When you mentioned home foundry, i did not expect this.I sure learnt something new today.In the first video i really had no clue of what you were up to, to seeing the end product and how the part was achieved.Amazing.
I feel very humble watching your work and I second Marty's statement that you are indeed a master at work here! At least to all us watching who are still in the "how hard can it be stage" and have absolutely no ideea of what we have to learn :-)! Thank you very much for sharing!
Thank you for your comment. "How hard can it be?" To make the perfect casting - all but impossible, I sure have not the equipment to do it. To make a good looking and very useable casting - well all it takes is patience, practice and perseverance plus a willingness to learn from every source available. Bear in mind that I have been at it for 60 years. There is a lot to learn and to be honest many people never seem to come to grips with that. But regardless research, learn, and study a bit then just get out there and give it a go. What can possibly go wrong? :-)!
Marty, My aim was to show it start to end but it really is hard to show all the little nuances that are involved in the process, if I got somewhere near it I am well pleased and I am glad that you enjoyed it. Master of the trade? well I don't know about that. I figure though that I know just about enough to know how little I really know!
Otterprince, Sadly, too few people know why or how to keep a sprue full or even see the slightest need for bothering to doing so. It comes under the heading of what John Campbell calls "the 6000 year old technology" used by many foundries. It is perhaps notable that it is easy to make a casting, any mug with a gas torch some scrap and a tin can, can do it but it is hard, damn hard to make a good casting - the full sprue is but one of the steps necessary to achieve the latter... Martin
Simon, Thanks for the comment. Of all the throttle bodies I used to make this one always just seemed to finish that little bit better. Sadly, now for reasons recently explained I no longer make these and they now come form China machined from solid billet. An horrendous waste of metal and although they don't look bad they just do not look right nothing like a good casting (not that I am biased 😏)… Martin
PGS, Thank you for your comment - I do appreciate it. Yes, It is a bit of a bother to have to reject a casting for what is a cosmetic as distinct from a functional defect. Clearly this casting would have done its job just as well as one without this visual imperfection. However the eventual buyers of these parts tend to take great pride in their vehicles and in particular in the "under hood" appearance thereof, so the casting - sadly - had to go!
JB, Thanks for the comment. I worked on that finish for many years before I got it to this level. It comes at a price - extra work in sand preperation and very low permeability in my sand which sure causes problems but I have managed to get round most of them.Martin
One of the many reasons I am keen to catch you on a trip to VIC in the near future, and of course finish my own foundry as well.. to learn from a master! cheers, Marcus
Ha ha love the "Beer Barrel" bosh!! excellent workmanship as usual,I've learned a few ideas from you, I coat all my tools like you do in contact with molten alloy with a zircon based refractory wash, including my pyrometer probe.
The beer barrel makes the best quench tank ever! I have another older and larger that is my fuel tank, I pressurise it to about 10 psi to push the fuel (diesel) to the burner. They are good solid tanks and they have to be after all one would not want one's beer container to spring a leak, that would be a tragedy! :). Instead of the Zircon wash I use a boron nitride "hardcoat " by ZYP coatings. It is very good, strongly repellent to molten aluminium, and my thermocouple has been in use now for many years and never suffered attack by the aluminium despite being often left in it for most of the day when I am gravity diecasting. Unfortunately its very expensive so while I also use it on my ladles and degassing lances as well I use something much cheaper on my drossing off spoon. The BN material is no good above 900 to 1000 deg C so its not suitable for copper base alloys. For that a zircon base wash Is the more suitable. I have used zircon based washes for a whole range of things and they always seem to work well... Martin
You should have more views. I liked and subscribed. I started with part 3, and will be going back to watch the rest. The finish right out of the mold was amazing. Looking forward to seeing how it was achieved.
Jerry, Thank you for your comment, the like, and the subscribe. Yes I think that I should have more views too - but then I am a bit biased :)As "Pooroldchap" (Checkout his intro) says "I am just trying to save a few books before my library burns down" and also to provide (hopefully) good information as a foil to those all too numerous videos that are well, ahem, and without wishing to be rude, lacking in what might be termed, technical and scientific rigor. More views would help in both these endeavours - hopefully they will come in time. The finish is achieved in the main through to use of very fine facing sand. I have a video in the can on making the facing sand and another on getting it ready for use - time permitting I should have these edited and up soon. I hope that you also enjoy parts 1 and 2.
I did enjoy parts 1 and 2. Thank you. I have learned so much from kind people such as yourself who are willing to give a little of their time to teach others. From making your own water glass and sand riddle to lost PVA casting. The techniques vary, which keeps things interesting. I will now have two foundry experts from England (I assume you are British) to learn from, you and myfordboy.
Again thank you for your comment and I am glad that you enjoyed parts 1 and 2. Giving the time is my pleasure.I have been at this casting thing for about 60 years (yes, I am old - way too old!) I am a qualified metallurgist and have worked in several foundries including a stint as a foreman in a gravity die shop and also 5 years as Foundry Metallurgist in a large (by our standards) Aluminium gravity die casting foundry who attempted (with some success) to make safety critical brake parts. I have also consulted for a few foundries and studied everything I can regarding anything to do with aluminium casting and indeed casting generally. It has been one continual learning process that I hope will not end until the library burns down - there is so much more to learn and try and - sigh - so little time.But, No, I am not British - I am in Melbourne Australia.
Jerry, I would like to know how you rate a youtube personality as a foundry expert? I assume that you have had many years of experience making moulds and melting various metals.
Jerry, For some reason TH-cam has withheld your comment of a day ago (as likely spam would you believe!) However I have read both versions of it and it would seem that we are on the cusp of a most unfortunate misunderstanding, I would like to try to peacefully and pleasantly resolve this situation. So can I ask that you come back to me in a private message that provides an address where I can contact you privately?
Really appreciate the videos. Would be interested in any further comments you might offer about the feed/gating system and the factors you feel are most critical to the surface finishes you achieve.
Sorry, but somehow I missed your comment earlier so hence this belated reply. There is no short answer to further comments re feed/gating or surface finish. Please allow me to ruminate on my reply and I will try and come back to you a bit later with a useful reply. Suffice it to say for now that the feed/gating system I use here is not technically perfect but it sufficies quite well, and getting that sort of surface finish in the end turned out to be fairly easy but took a good few years to come up with.
Apologies as I realize I’m inviting an education or perhaps a one word response…….everything. Let me restate. Are there any unique aspects in respect to mesh, composition, and conditioning of the facing sand, the prep, conditioning and pour temp of the metal, the alloy itself, and/or feed and gating system, or other, that you feel contribute to the consistency and quality of finish more than others? On the gating system, it looks consistent with what I was always taught, a good starting point being a non-pressurized system choked at the sprue with the runner and gates having several to four times the cross sectional area of the choke and the placement of the feeders would generally be toward the more massive portion of the part if the part was not of uniform cross section. On your throttle body (which I recognize as a Weber 48 IDA EFI conversion; another one of my hobbies!) it appears as what my foundry friends would have called a hot riser/feeder as opposed to cold, since it’s placed where the part is fed as opposed to the other end. All with the intent of getting the part to freeze back to the hottest source of metal. Per your comment, what would make it more technically correct? Best Regards, Kelly
Kelly, Ok let metry to get into it a bit. Surface finish first gating in a later reply. As you will have seen I use a facing sand. It’s a natural sand so its composition apart from a 0.5% addition of corn flour (wood flour is more traditional) as an anti expansion defect additive and its water level, is fixed. I go to quite some trouble over this sand, there is an upcoming video where I show how I grind it to make it much finer and then another video on how I prepare this ground sand for use using my aerator (I have a vid planed about the aerator too, might take a while so hang in there). Moisture level is important, too little and the sand rams tightly and gives a good finish but the mould is brittle and there can be a lot of parting line edge loss etc. Too much and the mould it much “tougher” and easier to work with but the finish deteriorates as the sand won’t ram as tightly and tends to get “supervoids” i.e. spaces bigger than a grain of sand on the mould surface. How one rams can have an effect some people start ramming when there is just a little sand over the pattern - always, always fill the box before starting to ram. Counter intuitively perhaps I have not found metal temperature to have much of an effect on finish (within reason of course) Efforts to lower temp to improve finish usually result in miss runs. I use 601 alloy (356 in the US) It’s a very good general purpose alloy that is easy to work with. Perhaps it will finish better than say the 12% Si alloy but again I have not found this to be much of a factor - unless of course you get some contamination with typically Sr this element seems to cause a metal mould reaction at a little more than the levels needed for Si structural modification, the castings take on a “burnt” appearance and often have gas under the skin. One should always pour aluminium in a calm, quiet, and controlled manner so as not to rupture the sausage like skin of oxide that it flows through. The use of overly high sprues of non tapered sprues and overly large sprues without decent pouring basins cause way too much turbulence which breaks the skin and the metal penetrates the sand as evidenced by rough sandy patches on its surface. Related is the problem of impact where the sand slams into the mould surface this will overcome the metal surface tension than holds the liquid surface smooth. The main contributor? - without doubt the use of the very fine facing sand but it is all important. But be warned this is but about a tenth of the story! Hope this helps.
Kelly, Ok let’s have a go at the gating. 1.4.4 is spoken of with almost reverential awe in much foundry literature as being the go to for good gating - but is it? Is the expectation that metal will instantly expand to fill 4 times the area without any turbulence and associated gas entrainment oxide generation and hydrogen level increase reasonable? Even a little knowledge of fluid flow would suggest that it is quite possibly a fantasy. Sure, when you break out the mould the 1.4.4 is nicely full of metal but when did that happen - how much of the metal in the casting arrived there through an only partially filled runner, aspirating as above on the way. Unfortunately getting any fluid to expand into a bigger passage and to fill it in a calm manner is very difficult. True, you don’t want a 1.1.1 type system either, that would entail jetting into the cavity, mould wall impingement and high turbulence levels. How one successfully slows down metalvelocity in gating systems is one of the great conundrums. Various casting techniques have been developed with just this problem in mind (Low pressure and tilt) but sadly they are often badly used. Filters can be a great help but again are often badly used. My system is not really a 1.4.4 it simply is what the pattern maker gave me but it is based on earlier work that he and I did. I have made thousands of this type of casting and my customer has never complained about any internal casting defects and he diamond machines the bores to a very fine finish. I get away with this system because it has low sprue height, is small and thus relatively high friction these factors keep velocities down, and of course because I do use a tapered sprue that runs full. Pour time for the 2 Kg casting is 10 - 14 sec.Yes, I always try to feeder gate as thus the last metal to enter the mould and therefore the hottest when fill is complete is in the feeder. The feeder extensions on top of the mould are there just to provide sufficient volume in the feeder. These are shell core sand and thus a bit less chilling that the green sand of the rest of the mould. The exothermic is the icing on the cake to ensure good feed. The golden rule is to sprue to the lowest point of the mould, metal to ALWAYS run uphill from there. Clearly my system violates this rule. So improvement could come from:1 Altering the sprue to comply with this rule and repositioning of the runner and gates accordingly 2 Using a filter in the runner 3 Altering the pouring basin, it is nothing like the correct shape it is in fact embarrassingly incorrect! I am currently working on this. 4 Use a tapered slot sprue instead of the round one, friction would increase and thus metal velocity would drop. However the rather tight fit of the casting in the box used makes these improvements difficult - I do not wish to go to a bigger box.The casting is certainly of the Webber EFI conversion type, check out my customer’s web site www.efihardware.com/Hope this helps if not ask away!
Thank you for the thoughtful replies. I will look forward to the video on sand preparation. Gating is always an interesting subject. Like most things in engineering, there’s theory and then there’s practice; what’s optimal and what’s sufficient, and they are rarely the same. For me in a home setting it is always that which most likely yields a useable part on first attempt which may put a lot more metal in the gating system whereas production settings always long for quality/yield/economics. I am familiar with your throttle body customer albeit from a world away. Thanks again. Best, Kelly
thanks very much for the videos , learning a lot . i have dabbled a little and am going to do some more , still getting gear together, when its only a hobby it can be hard to source stuff sometimes . like i am having a heck of a time trying to find sand fine enough but i just battle on with the green sand i have .always seems to be the case when you want something its down the other end of the country ( i am in the hot sunshine state) johno
Doing the videos is my pleasure. Keep dabbling you will get there. There is a lot to get together and there is a learning curve with all of it. Sand can sure be a problem to find. I assume that you have done the phone book thing. You could ask local foundries where they get theirs. (pick a small one to ask - in the morning as they often pour in the afternoon and will be too busy to talk then) You could ask any geology teacher that you can find if there are any sand deposits near where you live. You could even try just walking along the beds of local creeks and rivers. Look at any geological or mining maps of your area. Try researching the geology of your area - sand is everywhere. I have seen "play sand" in local hardware stores which occasionally is fine enough but some of it contains lots of small shell pieces which is not good but you might get away with it for Aluminium (but not copper base) alloys - check with a bit of acid (vinegar will do) any shell will bubble and dissolve. My very fine facing sand I make by grinding my normal sand in a sort of flour mill - will have a video out on this soon (I hope!) Surprisingly ground sand does work. I have even used sand from an old gold mine stamp mill it was fine crushed quartz, it worked, but not well enough to recommend. We are lucky down in the rainy cloudy south 2/3 of Melbourne is underlain by sand and some of the other 1/3 had patches of it. Not all was suitable but lots was. Alternatively you could just buy some petrobond but at about $4.00 per KG its a bit much for an occasional hobby - keep looking for the sand and put you money into a proper graphite crucible instead. Bit humid for foundry work up where you are :).
no foundry anywhere near me im in the bush down on the qld nsw border . i have been using playsand from the big green shed mulled with bentonite. i built a muller which works ok ( very slow though can only do a bit at a time ) just the sand is to course . i have only been doing aluminium using a steel crucible but i have a bought a clay graphite A10 to have a go at making some bronze .
None near you - well, you can't win them all! While they do make life a bit easier you don't really need a Muller - I don't have one. Do you have a mate within a reasonable drive of you who lives near a foundry? Incidentally I tested "play sand" from "Bunkings" and it was about 30% fine bits of shell! Now I know I am going to get myself into all sorts of trouble here (no correspondence entered into!) and I am sorry to sound a bit hard nosed, but you really should not melt aluminium in a steel crucible. I know, I know, lots of people do it but it is bad practice and I also know (only too well!) that proper crucibles are expensive however looked after properly they should do over 100 Aluminium melts so its probably well less than a few cents per kilo of melted aluminium. I paid $260.00 for my last A25 it holds 11 Kg of Aluminium at 100 melts that's around 20 cents a Kg - compared to other costs - fuel , metal, fluxes, degassing, etc., and my time that's chicken poo! Aluminium dissolves iron so sooner or later (usually sooner) your steel crucible will piddle metal all over the inside of your furnace, the floor, your legs, your boots, the kid from next door who just happens to be watching and who's father is a lawyer, etc. But this is not the worst of it ;- iron absolutely ruins aluminium, it interferes with proper metal feeding and makes the aluminium extremely brittle. I would never place any faith in an aluminium casting made via a steel crucible. But worst of all iron is the death of aluminium for there is no way of getting it out of the aluminium again, I am no greenie but we should not be destroying a resource like this particularly one that took so much electricity to make! ( they don't call aluminium "frozen electricity" for nothing!) The best thing one can do with iron contaminated Aluminium is bury it in a hole in the ground! Seriously, please throw that steel crucible away and buy yourself another A10. While you are at it ask the crucible salesman where you can get sand - he will probably know. Incidentally don't use the one crucible for copper base and for aluminium as the latter can have a very nasty effect on the castability of copper base alloys. Note that some copper alloys can be extremely penetrating when it comes to coarser sands so expect possibly very rough surface finish.
think i am going to have to plan a trip to the big smoke that is brisbane and get some more needed gear looking at about 8 or 9 hours driving round trip plus time there but if i can pick up enough things i need it would be worthwhile . of course there is also a limit to how much a bloke can spend when it is only a hobby and not a money making venture . any way keep up the videos please i am enjoying them i have watched them all and will be waiting eagerly for the next one .i had some firebricks shipped up from brisbane today to toowoomba because i was in toowoomba for the day and yep they are not quite what i wanted but i will keep and use them because to send them back would not be viable one of the joys of living in the sticks thanks john
I certainly understand the spending limit thing it applies to me too even though I do make money. I still cut every corner that I reasonably can in the interests of economy. However it is true that all hobbies do cost money - the only thing that you can do for nothing is nothing! - the trick I think is to know which corners can be cut without unduly compromising what you are trying to do and which can not. I would suggest an overnight stay in Brizzy as that would give you more time to talk to people. See if you can find a small foundry or two in Brizzy phone them and ask if you can visit and ask them a few questions. Generally the foundry industry is very "incestuous" every one knows everybody. Ask any one where you can get something and even if they do not know they will know someone who probably will. If you ask politely most foundry folk will bend over backwards to help you. If you do get to visit a foundry and ask them about sand have some very strong big plastic bags in your vehicle - you might get lucky and they might give you some sand - it might be old and not last much longer but it will be a start. Feel the sand they are using to get an idea of what the right moisture level feels like, look at everything in great depth, say little, and listen a lot. Good luck.I have more videos "in the can" just need to time to edit them but it takes forever! I envy you in living in the "sticks" I would love to do it but the wife does not drive and - groan - loves to shop so in the suburbs we are stuck!
Marty, I have been asked about a video on heat treatment before but there is a bit of a problem - how deeply do I go into it? At a superficial level it would be maybe a 1 minute video - so short to be not worth the effort - but in depth it would be much, much more and quite technical, interesting for some perhaps but I suspect boring for most. What is your preference? .. Martin
@@olfoundryman8418 thats the problem every where you try to find information about heat treating. But I think there is enough people interested in the technical aspects of it.
Do you have a video explaining what the brown powder you put on the riser is for? In one of your videos you refer to it as an exothermic, I believe. I'm a German student and new to metal casting. I found your channel a few days ago and have been watching your videos one after the other. They are very interesting!
Matthias, No sadly I do not have a specific video on the subject of exothermic use. I had intended to do one but ill health has for the moment stopped me from producing videos. I hope that the following information might be of some help. The exothermic I use is called "Ferrux NF" it is made by Foseco. The idea is that the exothermic catches fire when added to the top of the molten metal in the feeder. This generates a lot of heat which keeps the feeder liquid for longer and thus it is better able to provide liquid feed metal for the solidifying casting underneath. Basically the exothermic is a sort of thermite. I wish more people would follow your example - find my channel and watch - thanks for that... Martin
Martin, I've watched this a few times now and you make excellent videos and I do appreciate your skills. I was wondering what you put on the sprue after the pour with the spoon? I've watched several different foundry videos from different casters and I've not seen anyone else do that! You do such beautiful work with such skill. Thanks for sharing these.
Billy, I am glad you founf d the answer - it is a surprisingly common question - I must have been asked it dozens of times! I guess that its becasue I do seem to be the only YTer using it. I would not be without it as It sure helps my feeders work better.... Martin
Donald, Yes, I could do so but how detailed do you want me to get? The basic mechanics are easy and would take about 30 seconds in a video but the theory behind it gets a little technical and would take a lot longer... Martin
As always so much fun to watch what flux are you using at the end? And do.you use any during the melt? Thanks for the great videos I haven't done casting for years but my new shop will definitely have a spot. I'm interested in grain structure etc. Any books to recommend. Thanks again Rob in Wa. State
Robert, I assume by "flux that I use at the end" you mean the red powder that I put on the top of the feeders as soon as I have poured. It is an exothermic compound called "Ferrux NF" it is made by Foseco. Its job is to catch fire and generate a lot of heat that helps kept feeder liquid for longer so its better able to provide feed for the solidifying casting underneath. The best books on casting generally are those by John Campbell and if you are up for a big read then his "Complete Casting Handbook" is the go. Compared to all the other books out there Campbell's work is a breath of fresh air and is certainly the best information currently available. Its around 1200 pages - just the thing for those cold Aussie winters nights... Martin
@@olfoundryman8418 thanks I figured it was something along those lines. But it's been many years since I did and casting other than lost wax. There are so many products then there's the problem of getting them to sell in quantities I would use. Thanks for taking the time to write back. I'm in the middle of moving from about 30 miles from Canada to straight down to the border with Oregon. Grandma wants to be closer to grandkids lol I remember go off to my grandparents to get away oh well things change .thanks again for the great videos I'm going to go to patreon for everything I can after the move. I have lost so many of the best channels. Rob
Robert, Sorry, I missed part of the answer to your question. I do use a flux at the end of melting but not actually during it. I use "Coveral 11" it is made by Foseco and is what I believe is called a "drossing off flux". I sprinkle it onto the top of the melt after degassing and removal of the worst of the dross then I lightly rabble it into the surface of the metal and then allow it to sit for a minute of two. During this time the flux exotherms a little and then cools and becomes a dry powder - nice and easy to remove form the surface. I am not exactly sure how much good it really does - Bob Puhakka seems to think that fluxes are a lot of poisonous junk - well that's what I think he says - bit hard to tell some times!... Martin
A new favorite channel thanks for doing them what was the flux you used? Sodium carbonate? Also the amount and best pouring temp ill sure keep watching
Robert, The flux I used was a commercial one called "coverall 11" it is made by "Foseco" It is what is called a drossing off flux. I assume by your mentioning of Sodium carbonate that you have somewhere seen reference to washing soda (a form of sodium carbonate) being used as a degassing agent. This treatment although practiced by quite a few rather mistaken people simply does not work. In fact it increases the gas level - it does not reduce it. True washing soda is about 64% water and its this water as steam that bubbles out through the aluminium when the washing soda is plunged to the bottom of the crucible. The water reacts with the molten aluminium to form aluminium oxide and hydrogen the latter dissolves in the aluminium thus increasing the gas levels. The castings made in this video were poured at 720 to 730 deg C. The pouring temperature I use will vary with the casting concerned and the actual aluminium alloy (I use 4 different aluminium alloys) The temperature will vary accordingly from 650 deg. C to about 760 deg. C. Thanks for making me a new favourite... Martin
I'm really enjoying your videos! Your surface finish is the best! Did you change equipment for recording, as I noticed that the audio is greatly improved in this series. Thanks for sharing your knowledge with us.
Law46, Thank you for your comment. I am glad that you are enjoining the videos. That surface finish is the result of many years of pedantically striving to always get a better finish and it comes at a price in that the very fine facing sand that I use to get it slowly clogs up the backing sand and greatly reduces its permeability so every now and then I have to throw out all of the sand and start afresh. When you say that the audio is greatly improved in this series can you tell me pleases, improved compared to which of my other videos. The reason I ask is that there have been several changes in equipment. I used to use a small Nikon Coolpix camera, the lens in and out drive failed (it was clearly built to fail!) so I swapped to an even cheaper Nikon Coolpix for a video or two but the resolution was poor. Then I went to a GoPro hero 4 silver in a water proof case in order to protect the camera from all the dust which we figured had resulted in the Nikon failure. Sound quality (or volume rather) in the case was very poor, very poor indeed so I got a Rode external mic and a cheap case which I cut a hole through to connect the Rode. My main gripe is that the GoPro turns the volume down when ever it hears a loud noise so that if I drop a tool on the bench for example for the next 3 seconds or so my voice is recorded at a lower volume - there is no adjustment on the camera to stop this lowering of volume and it is very frustrating - a definite bad feature of the Gopro. I would love a second camera so I could film at another angle and cut and past to give a better view of proceedings - I am aware that the camera position that I use tends to give a very flat sort of image. However camera choice is a very trying business - unless of course one has unlimited funds - I don't.
In your early videos, I could not understand much of what you were saying, although it doesn't help that my hearing is damaged from many years of working as a welder & machinist. The older videos weren't a total loss as I'm able to learn just by watching. One of the best teachers I ever had was a boss at one of my first jobs. I worked for him for nine years, lot's of jobs that we did were two man jobs. I would just follow his lead, or I would be watching. One other TH-cam channel that I watch uses a Rode mic & his audio improved after he got that as well, but they are directional I believe so they don't pick up too well if you turn away from the mic. You mention a case for the Rode, is the mic in it? Keep the great videos coming. Regards, David
David, The case that I mentioned is for the GoPro not the Rode. I bought a cheap case for the Gopro and cut a small hole in it so that the lead from the Rode could plug into the camera. I could of course have cut a hole in the case that came with the Gopro but I did not want to attack that case. Unfortunately when actually making the moulds I am looking down at what I am doing so I am in effect turned away from the Rode which is mounted on a little bracket beside the camera. The camera and therefore the Rode are mounted above my head with both pointing down.I do have a small lapel type mic which does seem to work quite well and as its on 1 to 2 metre lead I could experimental mount it lower down - not possible to wear it on my lapel unfortunately because I move around too much. What I really need I guess is a wearable wireless mic but they are out of my price range. Sometimes I seem to pick up an electronic hum - possibly from a nearby flouro light - and I have to run the audio through a program called Audacity to remove at least some of this hum, I have noticed that this can distort the remaining sound and noticeably change my voice, I try not to have to do this. Perhaps a longer lead for the Rode and mounting lower down might be the go but then I have to keep it out of the sand! Ah, the troubles of YT video maker one has to be Cecil B, Mel Blanc, and Akira all at once :)All in all it does sound like it was the earlier Nikon filmed videos that have the poorer sound and I am past that stage. And thanks to your input I can see ways of improving sound in future videos. I note than some YTers including foundry videos do not speak at all I think that with this silence they miss a big opportunity to convey information, and that's what try to make my videos are about.Thanks for your input - I value it.PS. My hearing isn't that good either!
agustin, I do not actually regulate the argon pressure rather I regulate the flow to around 1.5 litres per minute with a flow meter and I guess the pressure takes care of itself i.e. what ever is necessary to produce that 1.5 litre flow rate... Martin
Nathan, Sadly I do not have any photos of the finished product. However my customer is EFI Hardware, they have a good web site easily found with Google. On that site they have hundreds if not thousands of photos of various throttle bodies and instillations thereof on a wide range of cars, some fairly radical stuff amongst it. You could happily spend an hour or two looking at it all, enjoy! Note I don't cast all their throttle bodies, just the good looking ones :).. Martin
hmmm ausie company , thats a pitty i live in europe myself its a nice finish on the pieces you make , you do a lot of steps i havent seen other "hobby casters" do , (the degassing with actual shielding gas , letting the aluminium cool in the crusible to a certan temperature before starting , the stuff you trow on the outlet of the cast at the end of the pour ) all that stuff probably has a lot to do with it looking at wat this company asks for a full trottle body setup , and wat i have to pay in schipping and import fees over that amount it might be worth the trouble to try my hand at making these things myself
I have been trolling through diy casting videos in an attempt to have a try at casting throttle bodies for my hobby car. Do you sell your products. I would like to buy six raw castings if you will. I would then only need to machine and make the adapters assuming they are ok size. Love your work and the videos are great. You have obviously been doing this for a long time to have such expertise and knowledge..
Mike, Unfortunately I do not own these patterns and therefore I can not sell castings to anyone else. EFI hardware own them and perhaps they will sell you raw castings but somehow I doubt it. As an alternative I am in contact with a pattern maker who has made quite a lot of throttle body patterns all of which I believe he still has but they are single throat units not doubles like the ones in this video. He can make you a double throat pattern if you wish but it would not be cheap! If you can use any of his single patterns it would be much cheaper. I can put you into contact with him if you wish, just PM me. Yes I have been doing this for a fair while I must have made many thousands of these things by now in fact another ten to mould tomorrow! (Yes, Sunday - have to make the most of the occasional cool days in a hot Melbourne summer)... Martin
Was a sizzler here today(Qld). Would not have been fun around a smelter. You have sure had some heat down there. Single throats may be easier. Its for a V12. Runners would be a cinch to make. Forgive my ignorance...whats PM. I will probably make my own pattern given the machinery I have at hand. It would have been so easy if I could have acquired your casting but I do understand having had plugs and molds made for myself and I would not have appreciated someone getting benefit from what I paid to have made. I will continue to learn from your tutorials. Thank you for the quick reply. Mike
Mike, Not for a jag are they? I have just done 12 single bodies and matching plenum chamber castings for a jag. (video in the can) I don't think the customer has made them for commercial gain but rather for his own car, so he may be amenable to re use of his patterns perhaps. PM is private message if you go to my channel and click "about" almost directly under the work "About" and under the total number of views my channel has had there are two little icons one is a flag the other is s sort of square cartoon type speech bubble thingie if you click on the latter it will allow you to send me a private message if you include your email address I will send you back a photo of the Jag throttle bodies and plenum chambers plus a photo of a few of the throttle body patterns that I may have lying around that the pattern maker may have left here. Note though that the castings are not exactly cheap and 12 of them is a good few dollars. Yep, we have had and are about to get more hot weather down here too - this aint the frozen south (pity!). We have had 43 recently. Today is only 20 so I have made a set of moulds (throttle bodies as it happens!) and I will pour them tomorrow morning when it will again be cool, later in the weak though, Ugh! 38 on the way.... Martin
Warren, I put an exothermic on the top of the feeders. Its job is to catch fire and generate a lot of heat , this keeps the feeders liquid for longer so they are better able to provide feed metal to the solidifying casting below. The exothermic is called "Ferrux NF" it is made by Foseco".... Martin
Hi! First of all thanks for your very useful videos! You put the thermocouple back into the molten Al, and say "so we can see what temperature it is" but, you don't say what temperature your going to pour at! How about a video on pouring temperatures? Regards, Matthew
Matthew, How remiss of me! I should of course said what the pouring temperature would be. A video on the subject would be rather short, but I will devote some thought to it. For now I pour most of my work in the 720 to 740 deg. C range. Some work like pistons for example where there is a necessity to pour cold I aim for 650 to 670 deg. C. Gravity die work can be anywhere from 760 all the way down to 690 deg. C depending on the job... Martin
@@olfoundryman8418 It's probably so obvious to you! I try to gauge things by the thickness of the mold, but is it as simple as that? I have found that the colder the pour, the less gas I get. I haven't made a degasser yet! Thanks again, regards, Matthew.
In the comments of your facing sand making video you told me about the book John Campbell's complete casting handbook, which included the 10 rules of casting... i have yet to get the book, as my budget is very tight... will get it as soon as i can responsibly do so... the topic of the proper temperature for pouring different metals using different casting processes seems to be a big and important topic... can you tell me if that book covers it well.. or if there may be an additional and fairly comprehensive resource i should look for; that you may be aware of? Thanks again for your genuine investment in the community... in the enrichment of my own life.. .of everyones... i am fearful of the fact that your videos are dated from years ago and they are only now appearing in my youtube queue... as it seems, i have been searching for videos on casting for longer than you've been posting videos on youtube... not a little topic from any angle.
Jim, I have heard that the 2011 edition of John Campbell's book can be found somewhere on the web for download although at about 1200 pages I would expect it to be a big download. Pouring temperature. I have had a bit of a look at Campbell's book and a good few others as well and there is very little if any pouring temperature recommendation, (none in Campbell) Many have only the rather trite recommendation "pour as cold as the casting will run" One or two have some vague recommendations and if you send me a PM with an email address that I can send a scan of said recommendations too I will do so. Thinking on it I can see why there is so little actual "Pour at this temp" info out there. It is just so dependent on so many factors and to look at just a small number of these factors - What is the mould material, Cast iron, steel, aluminium, copper, graphite, ceramic, stone, rubber, sand etc. Is the mould preheated or dried, is it poured hot, does it incorporate chills. To look at sand only, Green sand (how much clay how much water), hard sand (which resin system), synthetic green, what refractory - silica, olivine, chromite, zircon, or a newer synthetic. What grain size and shape, what permeability, how rammed, any mould dressings used and if so which. These factors alone are enough to cause wide variation in the pouring temperature required and we haven't even considered part shape and size, casting process or the real biggie, alloy used. Thus in reality it is possible only to give the most general of advice re pouring temperatures - that trite recommendation above is looking good! But perhaps a figure of 100 Deg C above the liquidus is a reasonable if vague starting point - try it and come down from there until the casting wont run. Sadly this will be different for every job and its why I keep a data sheet for each job that includes the temperature poured at and a lot of other info and comments besides. Foundry is certainly not a little topic, there are many different areas each with their own peculiarities and required knowledge base and all, to me, fascinating... Martin
Yes sir, sure can understand, when it's put into the proper context.. ... thank you again for your time. I wont trouble you to send me any extra emails... but will take your advice well, with respect for it... will try to do the same as you with taking notes and developing the experience.
The risers (I should really call them feeders for that's what they are) are big because they have to still contain at least some liquid metal when the last of the casting proper solidifies for in this way they can provide liquid metal to make up for the shrinkage that occurs on solidification. The sprue (the one that I pour into) has an entirely different job. Its function, and indeed its only function, is to deliver metal at the correct rate and in as undamaged a condition as possible to the mould cavity. A small tapered sprue together with a good pouring basin (mine could be better) poured in such a way that the basin and thus the sprue remain full during all of the pour is the best way to insure this. There is little worse that pouring a stream down the middle of an overlarge, and/or overly high sprue as many are wont to do as this causes a great deal of turbulence and splashing which in turn increases gas and oxide contamination of the metal as well as producing random rough spots. My use of these techniques is part of the reason that the products are so nice. And thank you for commenting to that effect.
Olav, As soon as I have finished pouring each mould I put some "Ferrux NF" on each of that mould's risers. This is an exothermic product made by "Foseco" it catches fire and burns producing a lot of heat, this keeps the risers liquid for longer so they are better able to provide liquid feed metal to the solidifying casting. And yes, there is rather a lot to learn - I still learn every day that I am in my foundry - there is always something new to investigate and try.
Thomas. I made the flasks. I gravity die cast the sides in a home made die from memory I cast the 170 sides needed in a single day. Took a while to do the machining bolting and doweling though. In a few weeks I hope to have a video out re my 50 year journey through moulding boxes - the good the bad and the just plain ugly! I hope to follow that up some more weeks later with a video on my thoughts for the best flask design taking into consideration they amateurs needs and what I have learnt....Martin
What is the approximate wall thickness of the ''tubes'? I would imagine they are quite thin (3~4mm?) Surface finish very impressive, looks like 'factory' / OEM
Peter, I used to make a whole range of these throttle bodies and many were made with up to 3 alternate core sizes to match different eventual machined bore sizes. The thickest is about 12 mm as cast while the thinnest is perhaps 6 mm when machined to the largest bore sizes they can get down to around 3mm. Better that factory/OEM 😀(well, I like to think so 😏)… Martin
I hadn't thought about finish machining (doh, ijit :o) ), Your finishes are so good I kinda assumed they were finished except for drilling throttle shaft holes. Don't have much experience with fuel injected cars (except Opel Manta GTE I had in 90's) so didn't realise how 'bad OEM could b?, I'm a motorc ycle mechanic (or was, 25 yrs ago) Modern bikes use pressure die-casting with minimal cleanup. I think I'm learning more from your site in a few days than I've learned in years of watching 'casting' video's. Thank's PJ @@olfoundryman8418
A great set of videos. thank you for taking the time to post them.. what s the exothermic compound that you use on top of the riser. I gather you are in Melbourne Vic,
Thank you for your comment, taking the time to post them is my pleasure. The exothermic compound is "Ferrux NF"it is made by Foseco. I use it on almost all my castings. Yes I am in Melbourne - eastern suburbs, are you close?
thanks for the topping compound. I will look it up. Thank you. I gather you were Aussie and there were hints of being in Melbourne. I come from Sydney and just getting into the Art of Foundry. I am a hobbyist machinist and expanding into casting. I have set up a foundry run on sump oil and burns cleanly that is 100% clean burning. your site is refreshingly practical and well presented again thank you.
@@FarmCraft101 , I buy it from the local "Foseco " branch. Although a UK company Foseco have branches all over the world. If they don't have one near you then just about any other foundry supply house should be able to supply an equalivant - just ask for an exothermic suitable for nonferrous metals. However I doubt that it will be available on line as - here in Australia anyway - it is classed as an explosive and therefore it can not be sent by post. Indeed the couriers who deliver it are supposed to be licensed to carry explosives. I buy it in a 25 Kg bag and that much should last the average hobbyist a lifetime. Maybe you can find a foundry close to you who uses it and but a few Kg off them for cash if you ask nicely... Martin
Land, I use what is called a "drossing off" flux. It is a commercial one called "Coverall 11" it is made by Foseco. I add it at the end of the melt just after degassing and its gets rid of all the oxide films floating around on the top of the metal... Martin
Scott, The extensions are made from resin coated shell core sand. The same sort as used to make the cores for these castings in part 1 of this video. I use a stronger sand (4% resin) for the feeder extensions and that way I get about 8 uses out of each one, they are tapered and just pull off the solid feeder immediately prior to break out. A coil of wire around the extension stops it cracking apart. The sprue extension is tapered the other way and will not pull off so I only get one use from them, I use a lower resin content sand for them (2 or 2.5%). Note that the shape of these sprue extensions is not optimum. They do not make as nice a pouring basin as is recommended for best practice, I am working on this but space on top of the mould is, as you can see, limited..... Martin
My pleasure to share. For degassing I bubble pure argon through the metal for about 7 minutes, the self built lance is designed to produce small bubbles as large bubble sizes are useless. Unfortunately many of the degassing techniques "out there" are also useless, some of them even increase gas levels - in particular plunging Sodium Carbonate in the form of "washing Soda" to the bottom of the melt as I have seen some do is very counterproductive as it effectively causes steam to bubble through the metal - bad in the extreme!I only use a final drossing off flux it is Foseco "Coveral 11" it works well and produces a nice dry dross but in humid weather the used flux dross mix can sometimes smell a bit of sulphides. The hot topping compound that I put on the risers (I should call them feeders as that's what they are but I am locked into the term Riser) is another Foseco product "Ferrux NF". It is an excellent product (No, I do not own shares in Foseco) it first exotherms to generate heat and then swells to form a red hot insulating pad over the top of the feeder. It dramatically improves feeding and I would not be without it. It has perhaps one small flaw in that a few small particles of the just burnt exothermic seem to float around in the air and very occasionally settle down the riser or sprue of a yet to be poured mould - very occasionally this mars the surface of the casting.I do tend to use commercial products as they work and its not worth fooling around with something that sort of does or maybe doesn't. I figure that making good castings is hard enough and that the last thing you need is something that you are not too sure about making it harder. (Unless of course you are into pain!)
Jon, Thank you for your comment. I do try to make the videos cool and interesting and it is nice to hear that I have had at least some success. The exothermic compound is "Ferrux NF". It is a commercial compound made by "Foseco". I use it a lot. Not only does it catch fire and generate a lot of heat as you can see but it also acts as an insulating cover on the feeder once the reaction dies down. Its only slight problem is that occasionally small pieces of ash drift around in the air and once or twice a bit of this has gone down the feeder of a just about to be poured casting and left a small mark on the surface of the casting.
K, The crucible that I bale out of is an A90. Alternatively when I lift the crucible out and pour directly from it in a shank it is an A25. The steel ladle I am using to bail out with and pour from in this video holds about 2.5 Kg... Martin
@@olfoundryman8418 on the a25 do you have a one man lifting tongs. If so do you have a vide of those ? Are the bought or did you make them ? I have an a30 I just bought but it is just me. Any suggestions? Thanks
K, Yes, for the A25 I have a crude pair of one man tongs. I place the A25 into a two man shank but I used to use the shank one man and some wheels. I don't really have a video of the shank but if you can send me an email address I can send you a picture of it. I find the A25 a bit of a struggle when its full of aluminium but I am a bit old and I think someone younger and fitter could manage an A30 on their own... Martin
bb, Yes, the use of a steel crucible is not a good idea. Iron will dissolve in the aluminium from such a crucible. The iron will combine with some of the aluminium and silicon within the alloy and form very brittle compounds that will seriously lower the ductility of the aluminium casting. In addition these compounds interfere with proper feeding of a casting during its solidification so greater porosity is likely. Also there is a safety risk as the steel crucible can suddenly get eaten right through and leak a stream of metal, perhaps down you leg! 😏 Once aluminium is contaminated with iron it is contaminated for ever it is NOT possible to get the iron out economically. Clay graphite crucibles are not cheap I know but all hobbies cost some money and this is something that money needs to be spent on. Well looked after a clay graphite crucible should last for around 100 or more melts with aluminium. If I see someone using a steel crucible on YT I stop watching and go look at something else... Martin
b b, No, stainless steel would be worse! The only thing stopping the aluminium attacking the steel is the layer of oxide on the surface of the steel. The oxide layer on the surface of stainless steel is a lot thinner and therefore provides less protection. Stainless steel is just as soluble as mild steel in molten aluminium perhaps even more so. Molten aluminium is a potent solvent for almost all metals.. Martin
Leticia, The material I put on top of the feeders immediately after pouring the casting is an exothermic called "Ferrux NF" it is made by "Foseco". Its job is to catch fire and generate a lot of heat, this helps keep the feeders liquid for longer so they are better able to feed the solidifying casting underneath... Martin
I am a mechanic and a hotrodder, Anytime I see a video on casting I think about all the guy's who cast and all the engine blocks that came out of Detroit. Man, That had to be hard work to do that all day!
jocrp6, Hard work indeed, and they did not get paid all that well - nor did they tend to live into old age - its an occupation that back then and even today to some extent takes a terrible toll on the human body...Martin
Mohammed, The exothermic compound is "Ferrux NF" , it is made by "Foseco" they have branches all over the world, it comes in 25 Kg bags and is not expensive. Most foundry supply companies would have an equivalent, you just have to tell them that it is for use on aluminium alloys so they know to provide a compound that ignites at the temperature of molten aluminium.Martin
Mohammed, Instead of exothermic compounds many foundries use insulating sleeves to line the feeders.Old time foundry men used to make liners up out of plaster of paris which they would oven dry before use. These days most foundry supply companies can provide sleeves made from a ceramic fibre and many foundries use these. Sometimes they will add either an insulating top to the metal in the sleeve once it fills or even some exothermic. Hope this helps. Martin.
Gamo, I assume that you me what gas do I use for degassing. I use industrial grade Argon and I bubble it through the metal for 7 minutes at a rate of 1 to 1.5 litres a minute. Note that it is 100% argon and not the argon CO2 mix that is also available.
Gamo, Yes, it is argon welding gas. Sorry to have to tell you this but washing soda does not work as a degasser. I do not know who started this washing soda thing off and I know that its use is popular but it just does not work.There are several different "washing sodas" but of the two most common there is straight sodium carbonate Na2CO3 it is usually a white powder and when plunged into molten aluminium it will perhaps give a small bubble or two but commonly it does not give off anything and therefore cannot possibly act as a degasser. Some people use it as a flux but it is useless for that too as it does not melt until about 830 deg. C and fluxes really need to be molten to work. The other common form of washing soda, usually as small clear crystals, and what might be called true washing soda is Na2CO3.10H2O It is the 10H2O that is the problem - its water of course - and in fact this washing soda is about 63 % water by weight. Plunging this stuff into molten aluminium is bad news as this water of crystallization as it is called is driven off by the heat and bubbles out through the aluminium - sometimes violently. But remembering that the hydrogen we are trying to get rid of got into the aluminium in the first place by the aluminium reacting with water in the air and in the furnace gasses I could not think of anything worst to do than to plunge something into the aluminium that causes water to bubble through it. In short this sort of washing soda will increase the hydrogen level in the aluminium not reduce it. It may not increase it much as the bubbling seems to be over and done with very quickly and just as it takes time to get hydrogen out of aluminium it takes time to get it in there too.Argon degassing requires fine bubbles to work successfully and lances like mine take a lot of looking after - its a bit of a pain to be honest.My suggestion is that if your work is fairly thin (and therefore solidifies quickly) and you melt quickly in a preheated furnace using a proper crucible (also preheated) and you do not let your metal get above 760 deg C and that you pour without delay as soon as its up to temperature and preferably on low humidity days you will not need to degas. If your work is on the thicker side you could have a problem but if you were getting away with it whilst using the dreaded washing soda then you will get away with it even better when you stop using the washing soda. Hope this helps.
Usefull info Martin, I've allways suspected that washing soda was an urban myth[never used it myself] a bit like melting brass into ingots to "clean it up", thelast thing I would do to brass is keep melting it, as an amateur using mainly old fittings I only melt once & have a lid on the crucible.btw is your furnace oil fired?.
Gamo, The flux that I use is a commercial product "Coverall 11" made by Foseco. The use of a flux is a bit problematic as many fluxes can be damp and the water that they thus contain will increase the hydrogen level of your melt. I make sure to dry the flux on a hot thick aluminium plate on top of the furnace before adding it to the top of the metal.
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When you mentioned home foundry, i did not expect this.I sure learnt something new today.In the first video i really had no clue of what you were up to, to seeing the end product and how the part was achieved.Amazing.
Richy, Yep, at first it can be a bit of a "what the" but once you see enough to get the basic idea it all makes sense... Martin
I feel very humble watching your work and I second Marty's statement that you are indeed a master at work here! At least to all us watching who are still in the "how hard can it be stage" and have absolutely no ideea of what we have to learn :-)!
Thank you very much for sharing!
Thank you for your comment. "How hard can it be?" To make the perfect casting - all but impossible, I sure have not the equipment to do it. To make a good looking and very useable casting - well all it takes is patience, practice and perseverance plus a willingness to learn from every source available. Bear in mind that I have been at it for 60 years. There is a lot to learn and to be honest many people never seem to come to grips with that. But regardless research, learn, and study a bit then just get out there and give it a go. What can possibly go wrong? :-)!
Thank you for taking the time to demonstrate the casting process from start to finish. You are a master of the trade. Marty
Marty, My aim was to show it start to end but it really is hard to show all the little nuances that are involved in the process, if I got somewhere near it I am well pleased and I am glad that you enjoyed it. Master of the trade? well I don't know about that. I figure though that I know just about enough to know how little I really know!
Thanks for the video, it brought back a lot of old memories, I appreciate someone that knows why and how to keep your sprue full :)
Otterprince, Sadly, too few people know why or how to keep a sprue full or even see the slightest need for bothering to doing so. It comes under the heading of what John Campbell calls "the 6000 year old technology" used by many foundries. It is perhaps notable that it is easy to make a casting, any mug with a gas torch some scrap and a tin can, can do it but it is hard, damn hard to make a good casting - the full sprue is but one of the steps necessary to achieve the latter... Martin
Great video! The hollow cores and finish are impressive.
Simon, Thanks for the comment. Of all the throttle bodies I used to make this one always just seemed to finish that little bit better. Sadly, now for reasons recently explained I no longer make these and they now come form China machined from solid billet. An horrendous waste of metal and although they don't look bad they just do not look right nothing like a good casting (not that I am biased 😏)… Martin
Love your work, and the finish is superb, I would be ecstatic with the one you rejected.
PGS, Thank you for your comment - I do appreciate it. Yes, It is a bit of a bother to have to reject a casting for what is a cosmetic as distinct from a functional defect. Clearly this casting would have done its job just as well as one without this visual imperfection. However the eventual buyers of these parts tend to take great pride in their vehicles and in particular in the "under hood" appearance thereof, so the casting - sadly - had to go!
Excellent video! Thanks for your time.
Thomas, as always the time is my pleasure, Thank you for watching
surface finish is amazing!
JB, Thanks for the comment. I worked on that finish for many years before I got it to this level. It comes at a price - extra work in sand preperation and very low permeability in my sand which sure causes problems but I have managed to get round most of them.Martin
One of the many reasons I am keen to catch you on a trip to VIC in the near future, and of course finish my own foundry as well.. to learn from a master! cheers, Marcus
Marcus, I await your aerial and look forward to meeting you in person. Martin
Good to
Watch a pro at work. Can you tell me what flux you use, Thanks for all your great videos
Ha ha love the "Beer Barrel" bosh!! excellent workmanship as usual,I've learned a few ideas from you, I coat all my tools like you do in contact with molten alloy with a zircon based refractory wash, including my pyrometer probe.
The beer barrel makes the best quench tank ever! I have another older and larger that is my fuel tank, I pressurise it to about 10 psi to push the fuel (diesel) to the burner. They are good solid tanks and they have to be after all one would not want one's beer container to spring a leak, that would be a tragedy! :). Instead of the Zircon wash I use a boron nitride "hardcoat " by ZYP coatings. It is very good, strongly repellent to molten aluminium, and my thermocouple has been in use now for many years and never suffered attack by the aluminium despite being often left in it for most of the day when I am gravity diecasting. Unfortunately its very expensive so while I also use it on my ladles and degassing lances as well I use something much cheaper on my drossing off spoon. The BN material is no good above 900 to 1000 deg C so its not suitable for copper base alloys. For that a zircon base wash Is the more suitable. I have used zircon based washes for a whole range of things and they always seem to work well... Martin
Great finish on the castings!
Misterbones. Yes, I am rather happy with that finish but it took many years to get there....Martin
amazing! i watched the video several time but i just cant get enough.
22Mon, Please feel free to watch it as many times as you like....😊.Martin
Thank you sir!
I hope it will generate
over works
Jimmy, Thanks for your comment.... Martin
Great video.Could you please tell us all about your temperature probe and the gage that it's connected too.Thanks very much
You should have more views. I liked and subscribed. I started with part 3, and will be going back to watch the rest. The finish right out of the mold was amazing. Looking forward to seeing how it was achieved.
Jerry, Thank you for your comment, the like, and the subscribe. Yes I think that I should have more views too - but then I am a bit biased :)As "Pooroldchap" (Checkout his intro) says "I am just trying to save a few books before my library burns down" and also to provide (hopefully) good information as a foil to those all too numerous videos that are well, ahem, and without wishing to be rude, lacking in what might be termed, technical and scientific rigor. More views would help in both these endeavours - hopefully they will come in time. The finish is achieved in the main through to use of very fine facing sand. I have a video in the can on making the facing sand and another on getting it ready for use - time permitting I should have these edited and up soon. I hope that you also enjoy parts 1 and 2.
I did enjoy parts 1 and 2. Thank you. I have learned so much from kind people such as yourself who are willing to give a little of their time to teach others. From making your own water glass and sand riddle to lost PVA casting. The techniques vary, which keeps things interesting. I will now have two foundry experts from England (I assume you are British) to learn from, you and myfordboy.
Again thank you for your comment and I am glad that you enjoyed parts 1 and 2. Giving the time is my pleasure.I have been at this casting thing for about 60 years (yes, I am old - way too old!) I am a qualified metallurgist and have worked in several foundries including a stint as a foreman in a gravity die shop and also 5 years as Foundry Metallurgist in a large (by our standards) Aluminium gravity die casting foundry who attempted (with some success) to make safety critical brake parts. I have also consulted for a few foundries and studied everything I can regarding anything to do with aluminium casting and indeed casting generally. It has been one continual learning process that I hope will not end until the library burns down - there is so much more to learn and try and - sigh - so little time.But, No, I am not British - I am in Melbourne Australia.
Jerry, I would like to know how you rate a youtube personality as a foundry expert? I assume that you have had many years of experience making moulds and melting various
metals.
Jerry, For some reason TH-cam has withheld your comment of a day ago (as likely spam would you believe!) However I have read both versions of it and it would seem that we are on the cusp of a most unfortunate misunderstanding, I would like to try to peacefully and pleasantly resolve this situation. So can I ask that you come back to me in a private message that provides an address where I can contact you privately?
Really appreciate the videos. Would be interested in any further comments you might offer about the feed/gating system and the factors you feel are most critical to the surface finishes you achieve.
Sorry, but somehow I missed your comment earlier so hence this belated reply. There is no short answer to further comments re feed/gating or surface finish. Please allow me to ruminate on my reply and I will try and come back to you a bit later with a useful reply. Suffice it to say for now that the feed/gating system I use here is not technically perfect but it sufficies quite well, and getting that sort of surface finish in the end turned out to be fairly easy but took a good few years to come up with.
Apologies as I realize I’m inviting an education or perhaps a one word response…….everything. Let me restate.
Are there any unique aspects in respect to mesh, composition, and conditioning of the facing sand, the prep, conditioning and pour temp of the metal, the alloy itself, and/or feed and gating system, or other, that you feel contribute to the consistency and quality of finish more than others?
On the gating system, it looks consistent with what I was always taught, a good starting point being a non-pressurized system choked at the sprue with the runner and gates having several to four times the cross sectional area of the choke and the placement of the feeders would generally be toward the more massive portion of the part if the part was not of uniform cross section. On your throttle body (which I recognize as a Weber 48 IDA EFI conversion; another one of my hobbies!) it appears as what my foundry friends would have called a hot riser/feeder as opposed to cold, since it’s placed where the part is fed as opposed to the other end. All with the intent of getting the part to freeze back to the hottest source of metal. Per your comment, what would make it more technically correct?
Best Regards,
Kelly
Kelly,
Ok let metry to get into it a bit. Surface finish first gating in a later reply.
As you will have seen I use a facing sand. It’s a natural sand so its composition apart from a 0.5% addition of corn flour (wood flour is
more traditional) as an anti expansion defect additive and its water level, is fixed. I go to quite some trouble over this sand, there is an upcoming video
where I show how I grind it to make it much finer and then another video on how I prepare this ground sand for use using my aerator (I have a vid planed about
the aerator too, might take a while so hang in there). Moisture level is important, too little and the sand rams tightly and gives a good finish but the
mould is brittle and there can be a lot of parting line edge loss etc. Too much and the mould it much “tougher” and easier to work with but the finish deteriorates as the sand won’t ram as tightly and tends to get “supervoids” i.e. spaces bigger than a grain of sand on the mould surface. How one rams can have an effect some people start ramming when there is just a little sand over the pattern - always, always fill the box before starting to ram. Counter
intuitively perhaps I have not found metal temperature to have much of an effect on finish (within reason of course) Efforts to lower temp to improve
finish usually result in miss runs. I use 601 alloy (356 in the US) It’s a very good general purpose alloy that is easy to work with. Perhaps it will finish better than say the 12% Si alloy but again I have not found this to be much of a factor - unless of course you get some contamination with typically
Sr this element seems to cause a metal mould reaction at a little more than the levels needed for Si structural modification, the castings take on a “burnt” appearance and often have gas under the skin. One should always pour aluminium in a calm, quiet, and controlled manner so as not to rupture the sausage like skin of oxide that it flows through. The use of overly high sprues of non tapered sprues and overly large sprues without decent pouring basins cause way too much turbulence which breaks the skin and the metal penetrates the sand as evidenced by rough sandy patches on its surface. Related is the problem of impact where the sand slams into the mould surface this will overcome the metal surface tension than holds the liquid surface smooth. The main contributor? - without doubt the use of the very fine facing sand but it is all important. But be warned this is but about a tenth of
the story! Hope this helps.
Kelly,
Ok let’s have a go at the gating.
1.4.4 is spoken of with almost reverential awe in much foundry literature as being the go to for good gating - but is it?
Is the expectation that metal will instantly expand to fill 4 times the area without any turbulence and associated gas entrainment oxide generation and
hydrogen level increase reasonable? Even a little knowledge of fluid flow would suggest that it is quite possibly a fantasy. Sure, when you break out the mould
the 1.4.4 is nicely full of metal but when did that happen - how much of the metal in the casting arrived there through an only partially filled runner, aspirating
as above on the way. Unfortunately getting any fluid to expand into a bigger passage and to fill it in a calm manner is very difficult. True, you don’t want
a 1.1.1 type system either, that would entail jetting into the cavity, mould wall impingement and high turbulence levels. How one successfully slows down metalvelocity in gating systems is one of the great conundrums. Various casting techniques have been developed with just this problem in mind (Low pressure and tilt) but sadly they are often badly used. Filters can be a great help but again are often badly used. My system is not really a 1.4.4 it simply is what the
pattern maker gave me but it is based on earlier work that he and I did. I have made thousands of this type of casting and my customer has never complained
about any internal casting defects and he diamond machines the bores to a very fine finish. I get away with this system because it has low sprue height, is
small and thus relatively high friction these factors keep velocities down, and of course because I do use a tapered sprue that runs full. Pour time for the 2
Kg casting is 10 - 14 sec.Yes, I always try to feeder gate as thus the last metal to enter the mould and therefore the hottest when fill is complete is in the feeder. The feeder extensions on top of the mould are there just to provide sufficient volume in the feeder. These are shell core sand and thus a bit less chilling that the green sand of the rest of the mould. The exothermic is the icing on the cake to ensure good feed.
The golden rule is to sprue to the lowest point of the mould, metal to ALWAYS run uphill from there. Clearly my system violates this rule. So improvement could come from:1 Altering the sprue to comply
with this rule and repositioning of the runner and gates accordingly
2 Using a filter in the runner
3 Altering the pouring basin, it is nothing like the correct shape it is in fact embarrassingly incorrect! I am currently working on this.
4 Use a tapered slot sprue instead of the round one, friction would increase and thus metal velocity would drop.
However the rather tight fit of the casting in the box used makes these improvements difficult - I do not wish to go to a bigger box.The casting is certainly of the Webber EFI conversion type, check out my customer’s web site
www.efihardware.com/Hope this helps if not ask away!
Thank you for the thoughtful replies. I will look forward to the video on sand preparation. Gating is always an interesting subject. Like most things in engineering, there’s theory and then there’s practice; what’s optimal and what’s sufficient, and they are rarely the same. For me in a home setting it is always that which most likely yields a useable part on first attempt which may put a lot more metal in the gating system whereas production settings always long for quality/yield/economics. I am familiar with your throttle body customer albeit from a world away. Thanks again. Best, Kelly
thanks very much for the videos , learning a lot . i have dabbled a little and am going to do some more , still getting gear together,
when its only a hobby it can be hard to source stuff sometimes . like i am having a heck of a time trying to find sand fine enough but i just battle on with the green sand i have .always seems to be the case when you want something its down the other end of the country ( i am in the hot sunshine state)
johno
Doing the videos is my pleasure. Keep dabbling you will get there. There is a lot to get together and there is a learning curve with all of it. Sand can sure be a problem to find. I assume that you have done the phone book thing. You could ask local foundries where they get theirs. (pick a small one to ask - in the morning as they often pour in the afternoon and will be too busy to talk then) You could ask any geology teacher that you can find if there are any sand deposits near where you live. You could even try just walking along the beds of local creeks and rivers. Look at any geological or mining maps of your area. Try researching the geology of your area - sand is everywhere. I have seen "play sand" in local hardware stores which occasionally is fine enough but some of it contains lots of small shell pieces which is not good but you might get away with it for Aluminium (but not copper base) alloys - check with a bit of acid (vinegar will do) any shell will bubble and dissolve. My very fine facing sand I make by grinding my normal sand in a sort of flour mill - will have a video out on this soon (I hope!) Surprisingly ground sand does work. I have even used sand from an old gold mine stamp mill it was fine crushed quartz, it worked, but not well enough to recommend. We are lucky down in the rainy cloudy south 2/3 of Melbourne is underlain by sand and some of the other 1/3 had patches of it. Not all was suitable but lots was. Alternatively you could just buy some petrobond but at about $4.00 per KG its a bit much for an occasional hobby - keep looking for the sand and put you money into a proper graphite crucible instead. Bit humid for foundry work up where you are :).
no foundry anywhere near me im in the bush down on the qld nsw border . i have been using playsand from the big green shed mulled with bentonite. i built a muller which works ok ( very slow though can only do a bit at a time ) just the sand is to course . i have only been doing aluminium using a steel crucible but i have a bought a clay graphite A10 to have a go at making some bronze .
None near you - well, you can't win them all! While they do make life a bit easier you don't really need a Muller - I don't have one. Do you have a mate within a reasonable drive of you who lives near a foundry? Incidentally I tested "play sand" from "Bunkings" and it was about 30% fine bits of shell! Now I know I am going to get myself into all sorts of trouble here (no correspondence entered into!) and I am sorry to sound a bit hard nosed, but you really should not melt aluminium in a steel crucible. I know, I know, lots of people do it but it is bad practice and I also know (only too well!) that proper crucibles are expensive however looked after properly they should do over 100 Aluminium melts so its probably well less than a few cents per kilo of melted aluminium. I paid $260.00 for my last A25 it holds 11 Kg of Aluminium at 100 melts that's around 20 cents a Kg - compared to other costs - fuel , metal, fluxes, degassing, etc., and my time that's chicken poo! Aluminium dissolves iron so sooner or later (usually sooner) your steel crucible will piddle metal all over the inside of your furnace, the floor, your legs, your boots, the kid from next door who just happens to be watching and who's father is a lawyer, etc. But this is not the worst of it ;- iron absolutely ruins aluminium, it interferes with proper metal feeding and makes the aluminium extremely brittle. I would never place any faith in an aluminium casting made via a steel crucible. But worst of all iron is the death of aluminium for there is no way of getting it out of the aluminium again, I am no greenie but we should not be destroying a resource like this particularly one that took so much electricity to make! ( they don't call aluminium "frozen electricity" for nothing!) The best thing one can do with iron contaminated Aluminium is bury it in a hole in the ground! Seriously, please throw that steel crucible away and buy yourself another A10. While you are at it ask the crucible salesman where you can get sand - he will probably know. Incidentally don't use the one crucible for copper base and for aluminium as the latter can have a very nasty effect on the castability of copper base alloys. Note that some copper alloys can be extremely penetrating when it comes to coarser sands so expect possibly very rough surface finish.
think i am going to have to plan a trip to the big smoke that is brisbane and get some more needed gear looking at about 8 or 9 hours driving round trip plus time there but if i can pick up enough things i need it would be worthwhile . of course there is also a limit to how much a bloke can spend when it is only a hobby and not a money making venture . any way keep up the videos please i am enjoying them i have watched them all and will be waiting eagerly for the next one .i had some firebricks shipped up from brisbane today to toowoomba because i was in toowoomba for the day and yep they are not quite what i wanted but i will keep and use them because to send them back would not be viable one of the joys of living in the sticks
thanks john
I certainly understand the spending limit thing it applies to me too even though I do make money. I still cut every corner that I reasonably can in the interests of economy. However it is true that all hobbies do cost money - the only thing that you can do for nothing is nothing! - the trick I think is to know which corners can be cut without unduly compromising what you are trying to do and which can not. I would suggest an overnight stay in Brizzy as that would give you more time to talk to people. See if you can find a small foundry or two in Brizzy phone them and ask if you can visit and ask them a few questions. Generally the foundry industry is very "incestuous" every one knows everybody. Ask any one where you can get something and even if they do not know they will know someone who probably will. If you ask politely most foundry folk will bend over backwards to help you. If you do get to visit a foundry and ask them about sand have some very strong big plastic bags in your vehicle - you might get lucky and they might give you some sand - it might be old and not last much longer but it will be a start. Feel the sand they are using to get an idea of what the right moisture level feels like, look at everything in great depth, say little, and listen a lot. Good luck.I have more videos "in the can" just need to time to edit them but it takes forever! I envy you in living in the "sticks" I would love to do it but the wife does not drive and - groan - loves to shop so in the suburbs we are stuck!
You should do a video on heat treatment. Love your video's. Nice smooth shining castings
Marty, I have been asked about a video on heat treatment before but there is a bit of a problem - how deeply do I go into it? At a superficial level it would be maybe a 1 minute video - so short to be not worth the effort - but in depth it would be much, much more and quite technical, interesting for some perhaps but I suspect boring for most. What is your preference? .. Martin
@@olfoundryman8418 thats the problem every where you try to find information about heat treating. But I think there is enough people interested in the technical aspects of it.
Long and interesting :)
Do you have a video explaining what the brown powder you put on the riser is for? In one of your videos you refer to it as an exothermic, I believe.
I'm a German student and new to metal casting. I found your channel a few days ago and have been watching your videos one after the other. They are very interesting!
Matthias, No sadly I do not have a specific video on the subject of exothermic use. I had intended to do one but ill health has for the moment stopped me from producing videos. I hope that the following information might be of some help. The exothermic I use is called "Ferrux NF" it is made by Foseco. The idea is that the exothermic catches fire when added to the top of the molten metal in the feeder. This generates a lot of heat which keeps the feeder liquid for longer and thus it is better able to provide liquid feed metal for the solidifying casting underneath. Basically the exothermic is a sort of thermite. I wish more people would follow your example - find my channel and watch - thanks for that... Martin
Martin, I've watched this a few times now and you make excellent videos and I do appreciate your skills. I was wondering what you put on the sprue after the pour with the spoon? I've watched several different foundry videos from different casters and I've not seen anyone else do that! You do such beautiful work with such skill. Thanks for sharing these.
Martin, continued reading the posts and found my answer. Thanks for sharing this wealth of information.
Billy, I am glad you founf d the answer - it is a surprisingly common question - I must have been asked it dozens of times! I guess that its becasue I do seem to be the only YTer using it. I would not be without it as It sure helps my feeders work better.... Martin
Could you do a video on the heat treatment after casting? This is one thing I know nothing about.
Donald, Yes, I could do so but how detailed do you want me to get? The basic mechanics are easy and would take about 30 seconds in a video but the theory behind it gets a little technical and would take a lot longer... Martin
As always so much fun to watch what flux are you using at the end? And do.you use any during the melt? Thanks for the great videos I haven't done casting for years but my new shop will definitely have a spot. I'm interested in grain structure etc. Any books to recommend. Thanks again Rob in Wa. State
Robert, I assume by "flux that I use at the end" you mean the red powder that I put on the top of the feeders as soon as I have poured. It is an exothermic compound called "Ferrux NF" it is made by Foseco. Its job is to catch fire and generate a lot of heat that helps kept feeder liquid for longer so its better able to provide feed for the solidifying casting underneath. The best books on casting generally are those by John Campbell and if you are up for a big read then his "Complete Casting Handbook" is the go. Compared to all the other books out there Campbell's work is a breath of fresh air and is certainly the best information currently available. Its around 1200 pages - just the thing for those cold Aussie winters nights... Martin
@@olfoundryman8418 thanks I figured it was something along those lines. But it's been many years since I did and casting other than lost wax. There are so many products then there's the problem of getting them to sell in quantities I would use. Thanks for taking the time to write back. I'm in the middle of moving from about 30 miles from Canada to straight down to the border with Oregon. Grandma wants to be closer to grandkids lol I remember go off to my grandparents to get away oh well things change .thanks again for the great videos I'm going to go to patreon for everything I can after the move. I have lost so many of the best channels. Rob
Robert, Sorry, I missed part of the answer to your question. I do use a flux at the end of melting but not actually during it. I use "Coveral 11" it is made by Foseco and is what I believe is called a "drossing off flux". I sprinkle it onto the top of the melt after degassing and removal of the worst of the dross then I lightly rabble it into the surface of the metal and then allow it to sit for a minute of two. During this time the flux exotherms a little and then cools and becomes a dry powder - nice and easy to remove form the surface. I am not exactly sure how much good it really does - Bob Puhakka seems to think that fluxes are a lot of poisonous junk - well that's what I think he says - bit hard to tell some times!... Martin
Thanks a lot I do remember using something the is awesome 1976 was a while ago lol
A new favorite channel thanks for doing them what was the flux you used? Sodium carbonate? Also the amount and best pouring temp ill sure keep watching
Robert, The flux I used was a commercial one called "coverall 11" it is made by "Foseco" It is what is called a drossing off flux. I assume by your mentioning of Sodium carbonate that you have somewhere seen reference to washing soda (a form of sodium carbonate) being used as a degassing agent. This treatment although practiced by quite a few rather mistaken people simply does not work. In fact it increases the gas level - it does not reduce it. True washing soda is about 64% water and its this water as steam that bubbles out through the aluminium when the washing soda is plunged to the bottom of the crucible. The water reacts with the molten aluminium to form aluminium oxide and hydrogen the latter dissolves in the aluminium thus increasing the gas levels.
The castings made in this video were poured at 720 to 730 deg C. The pouring temperature I use will vary with the casting concerned and the actual aluminium alloy (I use 4 different aluminium alloys) The temperature will vary accordingly from 650 deg. C to about 760 deg. C.
Thanks for making me a new favourite... Martin
I'm really enjoying your videos! Your surface finish is the best! Did you change equipment for recording, as I noticed that the audio is greatly improved in this series. Thanks for sharing your knowledge with us.
Law46, Thank you for your comment. I am glad that you are enjoining the videos. That surface finish is the result of many years of pedantically striving to always get a better finish and it comes at a price in that the very fine facing sand that I use to get it slowly clogs up the backing sand and greatly reduces its permeability so every now and then I have to throw out all of the sand and start afresh. When you say that the audio is greatly improved in this series can you tell me pleases, improved compared to which of my other videos. The reason I ask is that there have been several changes in equipment. I used to use a small Nikon Coolpix camera, the lens in and out drive failed (it was clearly built to fail!) so I swapped to an even cheaper Nikon Coolpix for a video or two but the resolution was poor. Then I went to a GoPro hero 4 silver in a water proof case in order to protect the camera from all the dust which we figured had resulted in the Nikon failure. Sound quality (or volume rather) in the case was very poor, very poor indeed so I got a Rode external mic and a cheap case which I cut a hole through to connect the Rode. My main gripe is that the GoPro turns the volume down when ever it hears a loud noise so that if I drop a tool on the bench for example for the next 3 seconds or so my voice is recorded at a lower volume - there is no adjustment on the camera to stop this lowering of volume and it is very frustrating - a definite bad feature of the Gopro. I would love a second camera so I could film at another angle and cut and past to give a better view of proceedings - I am aware that the camera position that I use tends to give a very flat sort of image. However camera choice is a very trying business - unless of course one has unlimited funds - I don't.
In your early videos, I could not understand much of what you were saying, although it doesn't help that my hearing is damaged from many years of working as a welder & machinist. The older videos weren't a total loss as I'm able to learn just by watching. One of the best teachers I ever had was a boss at one of my first jobs. I worked for him for nine years, lot's of jobs that we did were two man jobs. I would just follow his lead, or I would be watching. One other TH-cam channel that I watch uses a Rode mic & his audio improved after he got that as well, but they are directional I believe so they don't pick up too well if you turn away from the mic. You mention a case for the Rode, is the mic in it? Keep the great videos coming. Regards, David
David, The case that I mentioned is for the GoPro not the Rode. I bought a cheap case for the Gopro and cut a small hole in it so that the lead from the Rode could plug into the camera. I could of course have cut a hole in the case that came with the Gopro but I did not want to attack that case. Unfortunately when actually making the moulds I am looking down at what I am doing so I am in effect turned away from the Rode which is mounted on a little bracket beside the camera. The camera and therefore the Rode are mounted above my head with both pointing down.I do have a small lapel type mic which does seem to work quite well and as its on 1 to 2 metre lead I could experimental mount it lower down - not possible to wear it on my lapel unfortunately because I move around too much. What I really need I guess is a wearable wireless mic but they are out of my price range. Sometimes I seem to pick up an electronic hum - possibly from a nearby flouro light - and I have to run the audio through a program called Audacity to remove at least some of this hum, I have noticed that this can distort the remaining sound and noticeably change my voice, I try not to have to do this. Perhaps a longer lead for the Rode and mounting lower down might be the go but then I have to keep it out of the sand! Ah, the troubles of YT video maker one has to be Cecil B, Mel Blanc, and Akira all at once :)All in all it does sound like it was the earlier Nikon filmed videos that have the poorer sound and I am past that stage. And thanks to your input I can see ways of improving sound in future videos. I note than some YTers including foundry videos do not speak at all I think that with this silence they miss a big opportunity to convey information, and that's what try to make my videos are about.Thanks for your input - I value it.PS. My hearing isn't that good either!
what is the pressure you used for the argon? Excellent video btw.
agustin, I do not actually regulate the argon pressure rather I regulate the flow to around 1.5 litres per minute with a flow meter and I guess the pressure takes care of itself i.e. what ever is necessary to produce that 1.5 litre flow rate... Martin
@@olfoundryman8418 Thank you, Martin, I really appreciate the answer.
Thanks for sharing. What beautiful surface finishes. You don't have any pics of the carbs fully built do you?
Nathan, Sadly I do not have any photos of the finished product. However my customer is EFI Hardware, they have a good web site easily found with Google. On that site they have hundreds if not thousands of photos of various throttle bodies and instillations thereof on a wide range of cars, some fairly radical stuff amongst it. You could happily spend an hour or two looking at it all, enjoy! Note I don't cast all their throttle bodies, just the good looking ones :).. Martin
hmmm ausie company , thats a pitty i live in europe myself
its a nice finish on the pieces you make , you do a lot of steps i havent seen other "hobby casters" do , (the degassing with actual shielding gas , letting the aluminium cool in the crusible to a certan temperature before starting , the stuff you trow on the outlet of the cast at the end of the pour )
all that stuff probably has a lot to do with it
looking at wat this company asks for a full trottle body setup , and wat i have to pay in schipping and import fees over that amount it might be worth the trouble to try my hand at making these things myself
I have been trolling through diy casting videos in an attempt to have a try at casting throttle bodies for my hobby car. Do you sell your products. I would like to buy six raw castings if you will. I would then only need to machine and make the adapters assuming they are ok size. Love your work and the videos are great. You have obviously been doing this for a long time to have such expertise and knowledge..
Mike, Unfortunately I do not own these patterns and therefore I can not sell castings to anyone else. EFI hardware own them and perhaps they will sell you raw castings but somehow I doubt it. As an alternative I am in contact with a pattern maker who has made quite a lot of throttle body patterns all of which I believe he still has but they are single throat units not doubles like the ones in this video. He can make you a double throat pattern if you wish but it would not be cheap! If you can use any of his single patterns it would be much cheaper. I can put you into contact with him if you wish, just PM me.
Yes I have been doing this for a fair while I must have made many thousands of these things by now in fact another ten to mould tomorrow! (Yes, Sunday - have to make the most of the occasional cool days in a hot Melbourne summer)... Martin
Was a sizzler here today(Qld). Would not have been fun around a smelter. You have sure had some heat down there. Single throats may be easier. Its for a V12. Runners would be a cinch to make. Forgive my ignorance...whats PM. I will probably make my own pattern given the machinery I have at hand. It would have been so easy if I could have acquired your casting but I do understand having had plugs and molds made for myself and I would not have appreciated someone getting benefit from what I paid to have made. I will continue to learn from your tutorials. Thank you for the quick reply. Mike
Mike, Not for a jag are they? I have just done 12 single bodies and matching plenum chamber castings for a jag. (video in the can) I don't think the customer has made them for commercial gain but rather for his own car, so he may be amenable to re use of his patterns perhaps. PM is private message if you go to my channel and click "about" almost directly under the work "About" and under the total number of views my channel has had there are two little icons one is a flag the other is s sort of square cartoon type speech bubble thingie if you click on the latter it will allow you to send me a private message if you include your email address I will send you back a photo of the Jag throttle bodies and plenum chambers plus a photo of a few of the throttle body patterns that I may have lying around that the pattern maker may have left here. Note though that the castings are not exactly cheap and 12 of them is a good few dollars. Yep, we have had and are about to get more hot weather down here too - this aint the frozen south (pity!). We have had 43 recently. Today is only 20 so I have made a set of moulds (throttle bodies as it happens!) and I will pour them tomorrow morning when it will again be cool, later in the weak though, Ugh! 38 on the way.... Martin
What is that powder you spoon onto the hot aluminum in the vent pipes on top of the cast after you pour the mould ?
Warren, I put an exothermic on the top of the feeders. Its job is to catch fire and generate a lot of heat , this keeps the feeders liquid for longer so they are better able to provide feed metal to the solidifying casting below. The exothermic is called "Ferrux NF" it is made by Foseco".... Martin
Hi! First of all thanks for your very useful videos! You put the thermocouple back into the molten Al, and say "so we can see what temperature it is" but, you don't say what temperature your going to pour at! How about a video on pouring temperatures? Regards, Matthew
Matthew, How remiss of me! I should of course said what the pouring temperature would be. A video on the subject would be rather short, but I will devote some thought to it. For now I pour most of my work in the 720 to 740 deg. C range. Some work like pistons for example where there is a necessity to pour cold I aim for 650 to 670 deg. C. Gravity die work can be anywhere from 760 all the way down to 690 deg. C depending on the job... Martin
@@olfoundryman8418 It's probably so obvious to you! I try to gauge things by the thickness of the mold, but is it as simple as that? I have found that the colder the pour, the less gas I get. I haven't made a degasser yet! Thanks again, regards, Matthew.
In the comments of your facing sand making video you told me about the book John Campbell's complete casting handbook, which included the 10 rules of casting... i have yet to get the book, as my budget is very tight... will get it as soon as i can responsibly do so... the topic of the proper temperature for pouring different metals using different casting processes seems to be a big and important topic... can you tell me if that book covers it well.. or if there may be an additional and fairly comprehensive resource i should look for; that you may be aware of?
Thanks again for your genuine investment in the community... in the enrichment of my own life.. .of everyones... i am fearful of the fact that your videos are dated from years ago and they are only now appearing in my youtube queue... as it seems, i have been searching for videos on casting for longer than you've been posting videos on youtube... not a little topic from any angle.
Jim, I have heard that the 2011 edition of John Campbell's book can be found somewhere on the web for download although at about 1200 pages I would expect it to be a big download.
Pouring temperature. I have had a bit of a look at Campbell's book and a good few others as well and there is very little if any pouring temperature recommendation, (none in Campbell) Many have only the rather trite recommendation "pour as cold as the casting will run" One or two have some vague recommendations and if you send me a PM with an email address that I can send a scan of said recommendations too I will do so. Thinking on it I can see why there is so little actual "Pour at this temp" info out there. It is just so dependent on so many factors and to look at just a small number of these factors - What is the mould material, Cast iron, steel, aluminium, copper, graphite, ceramic, stone, rubber, sand etc. Is the mould preheated or dried, is it poured hot, does it incorporate chills. To look at sand only, Green sand (how much clay how much water), hard sand (which resin system), synthetic green, what refractory - silica, olivine, chromite, zircon, or a newer synthetic. What grain size and shape, what permeability, how rammed, any mould dressings used and if so which. These factors alone are enough to cause wide variation in the pouring temperature required and we haven't even considered part shape and size, casting process or the real biggie, alloy used. Thus in reality it is possible only to give the most general of advice re pouring temperatures - that trite recommendation above is looking good! But perhaps a figure of 100 Deg C above the liquidus is a reasonable if vague starting point - try it and come down from there until the casting wont run. Sadly this will be different for every job and its why I keep a data sheet for each job that includes the temperature poured at and a lot of other info and comments besides.
Foundry is certainly not a little topic, there are many different areas each with their own peculiarities and required knowledge base and all, to me, fascinating... Martin
Yes sir, sure can understand, when it's put into the proper context.. ... thank you again for your time. I wont trouble you to send me any extra emails... but will take your advice well, with respect for it... will try to do the same as you with taking notes and developing the experience.
Nice products, but why are your risers bigger than the one you pour into???
The risers (I should really call them feeders for that's what they are) are big because they have to still contain at least some liquid metal when the last of the casting proper solidifies for in this way they can provide liquid metal to make up for the shrinkage that occurs on solidification. The sprue (the one that I pour into) has an entirely different job. Its function, and indeed its only function, is to deliver metal at the correct rate and in as undamaged a condition as possible to the mould cavity. A small tapered sprue together with a good pouring basin (mine could be better) poured in such a way that the basin and thus the sprue remain full during all of the pour is the best way to insure this. There is little worse that pouring a stream down the middle of an overlarge, and/or overly high sprue as many are wont to do as this causes a great deal of turbulence and splashing which in turn increases gas and oxide contamination of the metal as well as producing random rough spots. My use of these techniques is part of the reason that the products are so nice. And thank you for commenting to that effect.
Olfoundryman ahh lots to learn. Thanks you, do you put ashes on top right after your pour?
Olav, As soon as I have finished pouring each mould I put some "Ferrux NF" on each of that mould's risers. This is an exothermic product made by "Foseco" it catches fire and burns producing a lot of heat, this keeps the risers liquid for longer so they are better able to provide liquid feed metal to the solidifying casting. And yes, there is rather a lot to learn - I still learn every day that I am in my foundry - there is always something new to investigate and try.
DAMN NICE WORK! WHERE DID YOU GET YOUR FLASK OR DID YOU MAKE THEM?
Thomas. I made the flasks. I gravity die cast the sides in a home made die from memory I cast the 170 sides needed in a single day. Took a while to do the machining bolting and doweling though. In a few weeks I hope to have a video out re my 50 year journey through moulding boxes - the good the bad and the just plain ugly! I hope to follow that up some more weeks later with a video on my thoughts for the best flask design taking into consideration they amateurs needs and what I have learnt....Martin
What is the approximate wall thickness of the ''tubes'? I would imagine they are quite thin (3~4mm?) Surface finish very impressive, looks like 'factory' / OEM
Peter, I used to make a whole range of these throttle bodies and many were made with up to 3 alternate core sizes to match different eventual machined bore sizes. The thickest is about 12 mm as cast while the thinnest is perhaps 6 mm when machined to the largest bore sizes they can get down to around 3mm. Better that factory/OEM 😀(well, I like to think so 😏)… Martin
I hadn't thought about finish machining (doh, ijit :o) ), Your finishes are so good I kinda assumed they were finished except for drilling throttle shaft holes. Don't have much experience with fuel injected cars (except Opel Manta GTE I had in 90's) so didn't realise how 'bad OEM could b?, I'm a motorc ycle mechanic (or was, 25 yrs ago) Modern bikes use pressure die-casting with minimal cleanup. I think I'm learning more from your site in a few days than I've learned in years of watching 'casting' video's. Thank's PJ @@olfoundryman8418
A great set of videos. thank you for taking the time to post them..
what s the exothermic compound that you use on top of the riser.
I gather you are in Melbourne Vic,
Thank you for your comment, taking the time to post them is my pleasure. The exothermic compound is "Ferrux NF"it is made by Foseco. I use it on almost all my castings. Yes I am in Melbourne - eastern suburbs, are you close?
thanks for the topping compound. I will look it up. Thank you.
I gather you were Aussie and there were hints of being in Melbourne. I come from Sydney and just getting into the Art of Foundry. I am a hobbyist machinist and expanding into casting. I have set up a foundry run on sump oil and burns cleanly that is 100% clean burning.
your site is refreshingly practical and well presented again thank you.
@@olfoundryman8418 Where do you buy it? Is it available online that you know of? (Recently found your channel and I'm learning a lot. Thank you!)
@@FarmCraft101 , I buy it from the local "Foseco " branch. Although a UK company Foseco have branches all over the world. If they don't have one near you then just about any other foundry supply house should be able to supply an equalivant - just ask for an exothermic suitable for nonferrous metals. However I doubt that it will be available on line as - here in Australia anyway - it is classed as an explosive and therefore it can not be sent by post. Indeed the couriers who deliver it are supposed to be licensed to carry explosives. I buy it in a 25 Kg bag and that much should last the average hobbyist a lifetime. Maybe you can find a foundry close to you who uses it and but a few Kg off them for cash if you ask nicely... Martin
Great vid! What was your preferred Flux?
Land, I use what is called a "drossing off" flux. It is a commercial one called "Coverall 11" it is made by Foseco. I add it at the end of the melt just after degassing and its gets rid of all the oxide films floating around on the top of the metal... Martin
Amazing work! What are your sprue and feeder extensions made from?
Scott, The extensions are made from resin coated shell core sand. The same sort as used to make the cores for these castings in part 1 of this video. I use a stronger sand (4% resin) for the feeder extensions and that way I get about 8 uses out of each one, they are tapered and just pull off the solid feeder immediately prior to break out. A coil of wire around the extension stops it cracking apart. The sprue extension is tapered the other way and will not pull off so I only get one use from them, I use a lower resin content sand for them (2 or 2.5%). Note that the shape of these sprue extensions is not optimum. They do not make as nice a pouring basin as is recommended for best practice, I am working on this but space on top of the mould is, as you can see, limited..... Martin
Great video and thanks for sharing. I wanted to ask about the compounds you used as deagsing, flux, and that you put above risers.
My pleasure to share. For degassing I bubble pure argon through the metal for about 7 minutes, the self built lance is designed to produce small bubbles as large bubble sizes are useless. Unfortunately many of the degassing techniques "out there" are also useless, some of them even increase gas levels - in particular plunging Sodium Carbonate in the form of "washing Soda" to the bottom of the melt as I have seen some do is very counterproductive as it effectively causes steam to bubble through the metal - bad in the extreme!I only use a final drossing off flux it is Foseco "Coveral 11" it works well and produces a nice dry dross but in humid weather the used flux dross mix can sometimes smell a bit of sulphides. The hot topping compound that I put on the risers (I should call them feeders as that's what they are but I am locked into the term Riser) is another Foseco product "Ferrux NF". It is an excellent product (No, I do not own shares in Foseco) it first exotherms to generate heat and then swells to form a red hot insulating pad over the top of the feeder. It dramatically improves feeding and I would not be without it. It has perhaps one small flaw in that a few small particles of the just burnt exothermic seem to float around in the air and very occasionally settle down the riser or sprue of a yet to be poured mould - very occasionally this mars the surface of the casting.I do tend to use commercial products as they work and its not worth fooling around with something that sort of does or maybe doesn't. I figure that making good castings is hard enough and that the last thing you need is something that you are not too sure about making it harder. (Unless of course you are into pain!)
+Olfoundryman yes the quality of your castings are really superb 👍👍👍
very wise words there from some one that knows what they doing
@@olfoundryman8418 Martin, found my answer to my question! Guess I should have read before writing! Thanks for the info. Bill
You earned a new subscribirser from France haha
Deezel, Greetings back from Australia and thanks for the subscription… Martin
do you take internee? :) would love to come all the way from other continent.
Kashif, No, Sorry I do not take on internees... Martin
Aah my hard luck.
What the exothermic compound? 6:02
Cool casting videos.
Jon, Thank you for your comment. I do try to make the videos cool and interesting and it is nice to hear that I have had at least some success. The exothermic compound is "Ferrux NF". It is a commercial compound made by "Foseco". I use it a lot. Not only does it catch fire and generate a lot of heat as you can see but it also acts as an insulating cover on the feeder once the reaction dies down. Its only slight problem is that occasionally small pieces of ash drift around in the air and once or twice a bit of this has gone down the feeder of a just about to be poured casting and left a small mark on the surface of the casting.
Big thanks for clarifying. Wait more interesting videos. :)
Jon, Working on more! Have several "in the can" but need to do the necessary editing - problem is that my computer is , like me, old and slow :)
Awesome video... what size of crucible?
K, The crucible that I bale out of is an A90. Alternatively when I lift the crucible out and pour directly from it in a shank it is an A25. The steel ladle I am using to bail out with and pour from in this video holds about 2.5 Kg... Martin
@@olfoundryman8418 on the a25 do you have a one man lifting tongs. If so do you have a vide of those ? Are the bought or did you make them ? I have an a30 I just bought but it is just me. Any suggestions? Thanks
K, Yes, for the A25 I have a crude pair of one man tongs. I place the A25 into a two man shank but I used to use the shank one man and some wheels. I don't really have a video of the shank but if you can send me an email address I can send you a picture of it. I find the A25 a bit of a struggle when its full of aluminium but I am a bit old and I think someone younger and fitter could manage an A30 on their own... Martin
@@olfoundryman8418 thanks that would be nice. Thank you. It is sanghamember@gmail.com
K, Hopefully you will have the pictures, if not let me know and I will try again... Martin
foundryman I told steel crucible is bad but seen some like taow do this. told steel ruin aluminum or something. this right?
bb, Yes, the use of a steel crucible is not a good idea. Iron will dissolve in the aluminium from such a crucible. The iron will combine with some of the aluminium and silicon within the alloy and form very brittle compounds that will seriously lower the ductility of the aluminium casting. In addition these compounds interfere with proper feeding of a casting during its solidification so greater porosity is likely. Also there is a safety risk as the steel crucible can suddenly get eaten right through and leak a stream of metal, perhaps down you leg! 😏
Once aluminium is contaminated with iron it is contaminated for ever it is NOT possible to get the iron out economically.
Clay graphite crucibles are not cheap I know but all hobbies cost some money and this is something that money needs to be spent on. Well looked after a clay graphite crucible should last for around 100 or more melts with aluminium.
If I see someone using a steel crucible on YT I stop watching and go look at something else... Martin
thanks you. would staneless steel work better?
b b, No, stainless steel would be worse! The only thing stopping the aluminium attacking the steel is the layer of oxide on the surface of the steel. The oxide layer on the surface of stainless steel is a lot thinner and therefore provides less protection. Stainless steel is just as soluble as mild steel in molten aluminium perhaps even more so. Molten aluminium is a potent solvent for almost all metals.. Martin
Fantastic job!
Thank you for the comment... Martin
Que pó é esse colocado após despejar o alumínio
Leticia, The material I put on top of the feeders immediately after pouring the casting is an exothermic called "Ferrux NF" it is made by "Foseco". Its job is to catch fire and generate a lot of heat, this helps keep the feeders liquid for longer so they are better able to feed the solidifying casting underneath... Martin
Beautiful Finnish
Thank you for your comment - please see my reply on the Diesel to LPG conversion part 2 video.
F'ing Amazing!
I am a mechanic and a hotrodder, Anytime I see a video on casting I think about all the guy's who cast and all the engine blocks that came out of Detroit. Man, That had to be hard work to do that all day!
jocrp6, Hard work indeed, and they did not get paid all that well - nor did they tend to live into old age - its an occupation that back then and even today to some extent takes a terrible toll on the human body...Martin
C'est pourtant pas la première fois que vous coulez des pièces, détendez vous un peu ! 🤗
Matthew, Good advice thank you... Martin
Thank you very much how can I get a exothermic compound
Mohammed, The exothermic compound is "Ferrux NF" , it is made by "Foseco" they have branches all over the world, it comes in 25 Kg bags and is not expensive. Most foundry supply companies would have an equivalent, you just have to tell them that it is for use on aluminium alloys so they know to provide a compound that ignites at the temperature of molten aluminium.Martin
Big thanks for the clarification, excuse me, Is there an alternative to them and how to get them
Mohammed, Instead of exothermic compounds many foundries use insulating sleeves to line the feeders.Old time foundry men used to make liners up out of plaster of paris which they would oven dry before use. These days most foundry supply companies can provide sleeves made from a ceramic fibre and many foundries use these. Sometimes they will add either an insulating top to the metal in the sleeve once it fills or even some exothermic. Hope this helps. Martin.
Big thanks Martin .What is Sand Casting
Mohammed, I suggest that you go to this explanation en.wikipedia.org/wiki/Sand_castingMartin
what is the gas you use
Gamo, I assume that you me what gas do I use for degassing. I use industrial grade Argon and I bubble it through the metal for 7 minutes at a rate of 1 to 1.5 litres a minute. Note that it is 100% argon and not the argon CO2 mix that is also available.
so it is argon welding gas I was using washing soda for degassing
Gamo, Yes, it is argon welding gas. Sorry to have to tell you this but washing soda does not work as a degasser. I do not know who started this washing soda thing off and I know that its use is popular but it just does not work.There are several different "washing sodas" but of the two most common there is straight sodium carbonate Na2CO3 it is usually a white powder and when plunged into molten aluminium it will perhaps give a small bubble or two but commonly it does not give off anything and therefore cannot possibly act as a degasser. Some people use it as a flux but it is useless for that too as it does not melt until about 830 deg. C and fluxes really need to be molten to work. The other common form of washing soda, usually as small clear crystals, and what might be called true washing soda is Na2CO3.10H2O It is the 10H2O that is the problem - its water of course - and in fact this washing soda is about 63 % water by weight. Plunging this stuff into molten aluminium is bad news as this water of crystallization as it is called is driven off by the heat and bubbles out through the aluminium - sometimes violently. But remembering that the hydrogen we are trying to get rid of got into the aluminium in the first place by the aluminium reacting with water in the air and in the furnace gasses I could not think of anything worst to do than to plunge something into the aluminium that causes water to bubble through it. In short this sort of washing soda will increase the hydrogen level in the aluminium not reduce it. It may not increase it much as the bubbling seems to be over and done with very quickly and just as it takes time to get hydrogen out of aluminium it takes time to get it in there too.Argon degassing requires fine bubbles to work successfully and lances like mine take a lot of looking after - its a bit of a pain to be honest.My suggestion is that if your work is fairly thin (and therefore solidifies quickly) and you melt quickly in a preheated furnace using a proper crucible (also preheated) and you do not let your metal get above 760 deg C and that you pour without delay as soon as its up to temperature and preferably on low humidity days you will not need to degas. If your work is on the thicker side you could have a problem but if you were getting away with it whilst using the dreaded washing soda then you will get away with it even better when you stop using the washing soda. Hope this helps.
Usefull info Martin, I've allways suspected that washing soda was an urban myth[never used it myself] a bit like melting brass into ingots to "clean it up", thelast thing I would do to brass is keep melting it, as an amateur using mainly old fittings I only melt once & have a lid on the crucible.btw is your furnace oil fired?.
u need good sand molders with education and experience?
Hajd, No, sorry its just the wife and I - we are nowhere big enough to need a moulder... Martin
where are you from?
ok hvala thank you all the best for you
Hajd, Melbourne, Australia... Martin
ok my sister lives there in Liverpool
what is the flux you are using
Gamo, The flux that I use is a commercial product "Coverall 11" made by Foseco. The use of a flux is a bit problematic as many fluxes can be damp and the water that they thus contain will increase the hydrogen level of your melt. I make sure to dry the flux on a hot thick aluminium plate on top of the furnace before adding it to the top of the metal.