"polishing a turd" LMAO !!! Love it. Good to see you back sir, always good to see someone who is interested in passing on his wisdom. Hope you and yours are well, always good to see what you've got to share. Thank you.
Donnie, Yep, I tend to laugh too when I see one of these "turd polishers" at work, but sadly if one looks at their stats they are the ones laughing! 😥 They have hundreds of thousands of subs and seem to make an absolute fortune from YT - no wonder they can afford the polish! Sigh - Life (and YT) are just not fair.😰 😱 We are surviving but in full virus lockdown AGAIN! … Martin
@@olfoundryman8418 But Martin you also need to feature one or two very cute dogs, having a well earned beer and dropping an ice cream container ice block on top of your freshly cast ingots or coins, then polish said items.
@@olfoundryman8418 Martin, I have to admit I watch just a few of the "shows". One has just exploded, he's a countryman of yours, I started watching him because if his Aussie humor, dumb things like a wee bit too much to drink. Dumb but funny. Another I wish like many others would try to come back, again because of his mix of sarcastic humor is "oilburner". I know, I think, why he hasn't uploaded in three years. Sad Anyway, I have three channels I watch for the knowledge being shared. Yours is by far number one, luckygen number two, and the third I just subbed to is here close to me in the SE states. Primarily cast iron but casts very close to your tradition, "Windy Hill". Thanks Martin, again, the lockdown is causing problems everywhere. Stay safe and stay healthy.
@CastingIron Engines like I told Martin, there's a really big difference between entertainment and knowledge. You can see the comments from people that don't know the difference between foundry, furnace, and forge. Take notice of how they prepare their flasks and how they remove their patterns. I fill in with other professional casters why waiting on Martin and for my entertainment watch the other weekly channels. One, I won't mention, has an aluminum boat he's planning on melting. Entertainment.
Mark, Yeah, Am considering a couple of mutts named "Crucible" and Ladle" or maybe "Furnace" and Fuel" or even "Copper" and Bronze". I can manage the ice block and even a Carlton zero but I will be darned if I am going to get 5k worth of tats. Suggestions for dogs names taken (no notice of) 😊... Martin
"Full as a goog", "Polishing a turd" .... only in Australia! Thanks Martin. When I see you making a failed casting I feel slightly less inadequate. It's nice to hear the reasons behind the failures though. Regards, Mark
Jeffrey, Thank you for saying so and while I will gladly accept any privileges that come with any knighthood I would rather that I caught up to those errant UT foundry people with 200,000 subs plus - 20 times mine - sigh life (and YT) isn't fair 😰😊.... Martin
Scruffy, A man, much wiser than I, once said to me " the man who has not made a mistake has not made anything". I do not mind showing a mistake/ failure particularly if as you say it is a learning exercise.... Martin
Just watched this again and I have to say this is about as good a video as you have ever done. Going through the two failures as you did was most educational. Not that I need this knowledge, (cos I know a bloke who does this) but for those with a real interest, this must have been great.
Gday Martin, it is a great thing you do here as in all of your videos, showing ALL and explaining the reasons as to how when and why. Thanks Mate, John, EC Australia.
Thanks for explaining the casting defects at the end of this one Martin. As a beginner/hobbiest, it is often not clear what errors are causing rejects.
Rotary, Most people struggle to correctly identify the cause of rejects. Myth and legend abound even amongst long time professionals. However most defects are down to bad metal (wrong alloy or just contaminated metal), bad pouring technique, bad gating technique, and insufficient feeding.... Martin
I was watching another fella on TH-cam and he clearly needs to watch your videos. Thanks for the lesson and the lingo helps me remember my years living in Oz.
William, Yeah, I have noticed a few like this too 😏and I do wish that they would watch. Make a comment on his video suggesting that he does. Lingo is free of charge.😊... Martin
Martin, thank you for yet another very educational video. Showing and explaining the "failures" is _very_ educational. I'm looking forward to your next video!
Bob, At the start of the next video I will show the two replacement castings (made yesterday) beside the ones they replaced with explanation - the difference is amazing.... Martin
I swear, you only use exothermic, to make folks ask what it is! Love the way the camera operator is managing to apply the exothermic as well. I have seen your polishing wheel and you have polished things for me, I am sure you could polish those ingots as well as anybody. Nice to see more results from those patterns I printed, including those odd side pieces, they seem to work well. Let’s hope someone else prints them too!
Nigel, Yep, and they keep asking! The patterns worked very well and I hope that those who do print and try them for themselves have the same success - they should. But, No, I am not going in for ingot polishing and I do not care how many more subs doing it might get me - a man has his pride.... Martin
@@olfoundryman8418 If you are going to polish an ingot, at least section and etch it, so you can then talk about the pattern of the metal flow in the ingot mold. :-)
I wilton, I have sort of already done that with some sections of a few ingots to show the size of the gas porosity in them. As a metallurgist I spent many "Happy" hours polishing metallographic samples - but that did have a purpose....Martin
Another example of how "maker" videos should be made. As with most things, the deeper you get into something, the more you need to know about it and I (dare I say "we") appreciate the effort you go to. You have the teaching ability to explain the beginner stuff in a way that makes the experts think about it too. I'm still very interested to purchase whatever castings you have left over from this series and look forward to meeting you. Thanks Martin
ViScAsh, Thank you for your comment. I am not certain about the ultimate destination of any boxes I do get together but I will keep you interest in mind... Martin
@@olfoundryman8418 Martin, I hope we get to see you use these boxes at least a few times in videos, before you get rid of them (if you do). It would be interesting to get your opinion on them as an experienced foundryman. And to see if you come up with any tips on ramming/whatever with this design. You're more likely to know the tricks to get the best out of them than the rest of us -- that's why we're watching you, not the other way around!
ViScAsh, Yes, I remember the conversation but I have not yet decided what to do with the boxes I am making (assuming that I finish them of course). I may sell them in which case as you got in first with the offer to buy I will give you first right of refusal. But I may keep them or I may give them away as some sort of viewer giveaway. I do not know yet....Martin
dfross, I certainly will try them out but I don't think they will require any different techniques to my existing boxes - time will tell though....Martin
@@olfoundryman8418 I think it is because they wanted entertainment in the first place, come across someone that do it with a bit of showmanship and stayed a while until the fun wears off. Yours is for the craftsman and detailed to the degree that scares people off because they realize it means hard work...
Cobus, Yes, you are right. People watch YT to be entertained and not so much to actually learn anything. This very much favors the "turd polishers". However I think the truth is that it does not take any more work to do it properly than it does to do it badly - you just have to be a little fussier and exercise a little more care. Its a question of taking at least some pride in one's work. Sadly and to my extreme disappointment it seems that many are not prepared to do this. It is more a game of "he who dies with the most subs/views wins", rather than quality of the end result being the decider. As I said to Craig "it is what it is" I won't change and I doubt the "TPs" will either... Martin
@@olfoundryman8418 Lets hope you do not let your dissapointment translate into fewer or lesser videos. Very few of your calibre prepared to share like you do. Thanks for doing so.
@@cobusbrits2, Quite the reverse - my disappointment just increases my resolve to correct the bad info out there. Its just at the moment I am unwell to the point I can not make videos - very frustrating - brain is fine but body is falling to bits! Hopefully this is a temporary situation .😏 Sharing is my pleasure.....Martin
Nice video Martin. Thanks for the part where you teach us what doesn't work! It's just as important as what does work. I'll be one of the guys making the patterns out of wood. For me it is a no brainer kind of decision. I am watching, learning and brushing up on things that I have forgotten. Time for me to start looking for sand. If I remember correctly there is a rather large deposit of Olivine sand no all that far from me. About 90kms. Might be worth taking a few plastic drums and filling them up!
Olivine sand - you lucky soul! Take the 10 ton truck and fill it up! Is is fine enough or do you have to crush it? Almost temps me to get on a plane except we are in lock-down! ... Martin
@@olfoundryman8418 It is sold as sandblasting sand all over the place. So my guess is that it is in variable size as it is a natural deposit. Might be wise to go there with some sieves and get what I need. Only problem will be that the sieve will allow all the fines through to. But I guess that is what washed sand is really all about. All I need is time. We are still in a graduated lock down. Everyone has to wear masks in public. Offices where you are all lined up like chickens are not really running yet. But the infection rate is stabilizing. Wash my hands is the way to go for all of us.
Mark, Used for sandblasting what a waste! Obviously then it is a sand deposit as against a solid rock one requiring crushing lucky lucky you. You do need some fines a one size sand is pretty useless - won't get enough strength for a start. In the size range required sieving is very slow will take weeks to sieve enough. However first you use a 1.5 mm sieve to get rid of the big useless stuff and then you use air sizing. I did this once a long while ago and it does work quite well, if you wish I can explain with diagrams etc how to do it not hard to set up just a bit messy and you need a very still day.... Martin
@@olfoundryman8418 You even wonder if I'm interested! Of course I'm interested. I was thinking about requiring fines and a upper size after I typed about washing it. Rather silly when you think of how the sand will hold a shape. If they are all graded as it would be in sandblasting sand it will never ram up and keep a formed shape. So yes please I am most interested in your explanation. You are making me wonder if it is anything like an old time seed and chaff separator. I remember working around one when I was a little munchkin.
Mark, I will reply on this via email might take me a little time though as I have to do a few drawings (scribbles) 😊... Martin PS, seed and chaff - yes!
Thank you for sharing your experience. Especially interesting are your insights into setting up for a successful pour, e.g. temp, size and taper of the sprue, pouring basin, shape of the runners, and this time what air and gas defects look like, and permeability of the sand. Excellent stuff.
D. Jeff, I hope to have a short video out in a week or so dealing with just this aspect of making a superior casting. Sadly, my sand is not one of the more permeable and this does cause me problems although I have learnt to get around them (mainly 😊) (use of a thin vent wire.)....Martin
Dennis, I was lucky and managed to get my hands on some very stiff stainless steel wire used by surgeons to hold bones together, it is 1.25 mm diameter although the tip has worn down to about 0.5 mm. This works very well but I have used the central wire from a child's sparkler, its a bit soft and bends all to easily even if you take it from an unused sparkler (way to soft if it has been lit!). For cores where I want a really good vent I use a knitting needle about 2 to 3 mm diameter - this also helps the CO2 for curing the core get in easier.... Martin
Dennis, Well I hope there are a few mussos down here too in which case it should be available locally - get some and give it a go and let us know how you get on with it... Martin
Mister. I have a short video shot that I hope to release in the next week or so on just this subject. It shows how to get this control using good pouring basin and sprue design. IF it is well received I may expand on it by doing videos on filling time and sprue calculations. … MARTIN
Its good to see proper gapping of the crucible to Furnace wall looks about 30-40mm it amazes me how many people make this gap way too big! and then get poor performance from there and wonder why... joel
TheSilver, Yes, I guess the gap is about that with this crucible - it is an A 90. But I also melt using an A 6 in this furnace and it does look a littler funny! Furnaces are a little like garages, workshops, and lathes - they are never big enough and never small enough. But I figure that a big furnace will fit a small crucible while a small furnace will not fit a big crucible. But you are right, little crucible in big furnace means lots more fuel and lots more time😰.... Martin
Great video as usual. I for the first time today tried sand blasting my 3D printed item, it worked very well to smooth the surface. Something to keep in mind
@@olfoundryman8418 You're welcome! I saw some vids on the web, one suggested blasting at a 60 degree angle. I tried it on PLA on a very hard to sand part and it worked very well, especially in preparation for a primer fill operation. I enjoy your videos and hope to see more in the future. Funny my first time talking with you, you had a pretty negative opinion pairing 3D printing with casting, I'm glad you found ways to incorporate 3D into your work. Stay safe out there!
caltick, It sounds very interesting and I will definitely give it a try - I have a few 3D prints that defy sanding and I had given upon (hence my reservations re 3D printing for patterns). I have to say that they sure worked well enough for these box sides and the ability to print complex shapes particularly if finishing is simplified makes the idea very attractive - if only it had been around 30 years ago - sigh!.... Martin
creast, Thank you for saying so. Sprues and pouring basins are the most important thing and in an upcoming video I go its this a bit more, stay tunned....Martin
Well done Martin and thanks for sharing what does happen, sad to say I’ve come across some casting problems today and third attempt is still not right but maybe recoverable-maybe. Always a pleasure to watch, cheers. Peter
G'day Martin, I sent you an email in response to your generous offer but you may not recognise it as me PGS , my name is Peter Stofmeel sorry for not identifying myself. Cheers
Hi, Sir, it's impressive to see you working and teaching at same time. More impressive is to see the passion with you do the job. I already saw almost all your videos wich are a great school to me and i already learn some small secrets that gave a huge change in the results for much better than i was achiving. One matter i still couldn't find with good precision in real world is about temperatures/problems. I know the melting point is 660ºC and in general the recomended temperature to poor should be around 750ºC. But i would like some more detail about the real temperature for each grade of aluminum and specially how to control that temperature. Also for experienced people like you the trained eye can read some signs about "where" is that temperature without special tools. That experience we can't find on books. Personally i deal with a big problem to control precisely temperature because i melt aluminum with an induction heater (i only melt 500gr at each time for smal pieces) and i can't use a thermocouple, once induction interfere with the metal sensor. And also with a IR thermometer, the reading are not to much precise... unless i could spent some thousands of euros in an industrial grade IR thermometer. Also could be good to listen the kind of problem we can get with too hight temperature and with too low temperatures. Hope one day you can do some video talking and showing examples about this topics like that one you did with tittle " Possibilities". So usefull that one!! Keep the good job and congratulations for share your knowladge with us. Thank you.
Paulo, To be honest I do not have much experience with measuring the temperature of molten metal in an induction furnace. My one experience was with alnico magnet alloy at around 2000 deg C. I used a Leeds and Northrup optical pyrometer model 8622 or 8621. I note that there are at least two of these for sale on eBay USA at the moment for around US$180. They are a good reliable instrument and are easy to use - I do not know but assume that they will go down as low as 750 deg C. (I would give my back teeth for one of these instruments!) I thought that maybe the use of an MIMS type K couple might have been ok with induction as the metal sheath plus the fact that the two thermocouple wires are close together and side by side - but I do not really know. For sure the (cheap) IR type of instrument has a big problem in that it relies on the emissivity of the metal surface. The problem here is that with aluminium in particular (and I suspect other metals as well) the emissivity varies wildly with the condition of the metal surface. If, for example, you were to take a reading of the metal after it had been sitting for a while then push the oxide on the surface aside to reveal a clean surface and immediately take another reading the two readings would likely be very different. Clearly such readings would be of no use as which one is correct? You can sometimes cheat a good reading by aiming the instrument at the crucible wall close to the molten metal - the emissivity of the crucible does not vary like that of the metal. BUT is the crucible at the same temp as the metal - with induction and say a graphite crucible that could be very debatable. Trying to judge the metal temp by its colour as perceived by one’s eye is hopeless! The temps we are talking about are around the range at which molten aluminium first starts to glow. The problem is that the ambient light greatly effects your eyes perception of the colour of the molten metal. My experience here is to have (often) stood beside a furnace of molten aluminium at about 750 Deg C all day. I knew the metal was at 750 deg C because I had a thermocouple in it. If it was a bright sunny day outside (big open door and lots of windows to let the outside light in) the metal would look quite silver but if a cloud came over the sun or if it was a cloudy day the metal looked quite a bright red. My perception of the colour was of no value in temperature determination ☹. If you cannot fine one of those Leeds and Northrup thingies then I suggest the following. Get a MIMS type K thermocouple preferably of fairly small diameter - they are on eBay everywhere and cheap. Repeatedly heat and cool the sheath for a bit more that the eventual immersion length to oxidise the sheath surface. Paint the surface with something like Boron Nitride Hard coat by ZYP Coatings. This material is expensive but provides the best protection against attack by molten metal. (I last paid about A$250.00 for a gallon of this material and it was one of those silly little American gallons 😊). However I believe it is possible to buy this or a similar material in a 1 pint size - see here for example www.graphitestore.com/pyro-paint-634-bn-boron-nitride-anti-oxidation-coating Still not cheap but very good - assuming it’s as good as the ZYP product! I clean off any aluminium and reapply the hard coat at the end of every day. My current thermocouple (6mm diameter) has lasted well over five years and still going strong despite being immersed in molten aluminium for hours at a time on hundreds of occasions. Take a guess when your metal is a little on the hot side. Switch off the induction power and immerse the preheated (in a nearby gas flame for example) thermocouple in the molten metal - the reading should come up or down to a steady figure quite quickly - this is the temp of your metal. Power back on and repeat the process or wait till the temp drops to what you want then pour the casting. In time you will get to know how long the power needs to be on for to get close to the temp you need. This would be my approach. Good luck and please let me know how you get on…. Martin
@@olfoundryman8418 Hi Sir, Thank you for your comments. Really good to listen from you. I was already looking for that pyrometer of Northrup at ebay and it really catch my eye. The price is not so big as i was thinking after read your info. Let's say... it's affordable. But i always have two concerns... First, is second hand precision instrument and always think if it is working good, and specialy is accurate and calibrated? If not.. how to fix? Who will fix?.. can be a problem. But for the price i would take the chance. The second concerne and the worst, is we are (Portuguese people) almost forbiden to import from USA. Why?? I don't know, but, everytime we import from USA, in the end the price goes up almost 3 times with taxes and import duties. It's funny, because from China is different. But i still didn't give up and i will try to find support about specs and how to use it. One question about this pyrometer: Once is optical instrument does it not suffer the same problem as IR thermometer as you explained? Well, another excellent idea you gave is about that pyro paint with boron-nitride. I have some K type thermocouple at home and one of them is rated for 1200ºC with 3mm diameter and 150mm long. And lucky i am this time, i can buy here boron-nitride pyro paint in form of aerosol can. Not the best... but enought to give a try. I also tried with another ceramic thermocouple type S to read the molten aluminum. And to do that i build a smal inox steel sleeve to protect ceramic tube once i immerse the probe on crucible. But readings was influenced by the magnetic field of induction heater because proble is also metal inside and also was very slow to reach the hight temperature of crucible. Now you gave that idea to warm up probe with a flame to equalize temp aprox and do the reading with power off of indution heater, and that, i will try next time. I am also thinking to build a small forge sized with my small crucible working on propane. In this way it will be easier to use that K-type 1200ºC thermocouple protected with boron-nitride. The best of induction heater is how fast it melts aluminum without big mess around. Easy process. But a hell to control temperature... Thank you again and keep teaching us with your huge knowlege! I am still thinking about that Northgrup optical pyrometer.... :):)
Paulo, My understanding - and I might be wrong - is that IR type temperature indicators rely on infra-red radiation from the metal being measured, as I have already mentioned the amount of this radiation varies as the thickness of the oxide film on the top of the molten metal. Instruments of the Leeds and Northrup type do not measure any radiation from the metal instead they compare the colour of the metal which is exactly corelated with its temperature with the colour of a lamp bulb type element within the machine. The lamp bulb element is within the instruments eyepiece superimposed on the view of the metal being measured and by adjusting the voltage on the element its colour is made to match that of the metal this gives a temperature reading. As you can see these are quite simple instruments - not a lot to go wrong! I guess that you could check the calibration of the instrument by taking readings of metal whose temperature is also being measured by a type K thermocouple.... Martin
Rupert, Too little too late and badly, very badly organised - hotel quarantine for those flying in was a farce with security Guards - And I use the term very loosely - trading sex for freedom, that is if they did bother to turn up for work! Heads need to roll!.... Martin
Jim, Thank you for your comment. I am not as well as I would like and am struggling a bit with the physical side of these videos (hence the slowness of publishing). Last time I spoke to lucky he was indeed well. I hope to see him soon but with Melbourne in lock-down - again! - he would be unwise to venture the 80 or so miles to get here... Martin
As ever educational Martin It shows the differences between our sands, finish is about the same as you have a decent fine green sand but my oil bonded shows very little expansion stress. As ever looking forward to your next episode mate.
Andy, Yes, it does appear that Petrobond has a few advantages, one of which is lower susceptibility to these wretched expansion defects. There will be a short interlude covering another subject before I get to the next episode... Martin
Andy, Yes I have heard this and many do not like the "feel" or smell of it, then there is as SW pointed out the disposal problem. It also slows solidification so mechanical properties are probably a bit lower but metal will run further and thinner in it (or so I have been told).. Martin
Yes, I think it runs better, I wear gloves when handling it, it can make pulling it out of the sand to water cool a little bit of a gamble, as thick parts do stay molten so much longer. & there are pro's and con's to that. but for me doing a lot of large thin items it works well, horses for courses I guess.
Farm, I have a separate cheap little air regulator set at 15 PSI just for the blow gun. Even so I use the gun with care typically pointing it away from the mould when I first pull the trigger as there always seems to be an initial pulse of stronger air. I never point it at any sharp sand edges and am very careful to hold the gun a ways back with delicate stuff like text.... Martin PS. Save your scrap for those turds - at least that way it won't get used for "proper" casting stuff 😊 (then throw the ingots away!)
@@olfoundryman8418 Thank you! I hope to make some of your molding boxes soon, and will probably do a video of it. Of course I will throw some love your way, recommending your channel in the vid. You deserve more views. Are you still planning on doing the final episode where you do the pins? You may be interested in my latest video where I try to cast a coin with some detailed small text using investment plaster, but fail many times. I'm sure you will cringe at many of my attempts. Watching you, I've learned that I need to make proper pour basins. I could sand cast it if I had a pattern with some draft, but I'm really trying to perfect my investment casting process.
Thanks for showing the rat tail defects. I have read about those, but good pictures of what they really look like have been hard to find. Looking forward to the machining video. I have no milling machine though - is it worth casting flask sides without one? So far all my flasks have been wooden. Good health to you and yours, Jeff
Given that you probably have a range of wood working tools, you can probably get acceptable results using a hand file, an angle grinder and an orbital sander. Keeping the file, any sanding discs and sand paper solely for use with aluminium will also prevent cross contamination from other metals. As an example I have a file dedicated to use with melamine iron on edging for cabinet work that is kept separate from other files.
Jeff,. The whole idea of this series on making your own boxes was that it can be done WITHOUT a milling machine or a lathe. I believe that we will end up with very usable flasks without the use of such machines. Hang in there and see what I wind up with and then decide if its for you. If you do make some I believe that like me you will never regret the effort that it takes.... Martin
Good morning over there, been studying your foundry lid. I'm making my own almost the same size of yours about 2 1/2 " smaller. I was able to figure what size yours was when you said it had a A90 crucible. My question deals with the can action on the lever to rise the lid. It seems that you have to rest the lid on the edge when it swung out the way to get to the crucible. Do you have a flat spot on the cam so it does have to ride on the refractory of the lid. On my lid which is close to the same size as yours it weighs right at 175 pounds. Curious how long has this lid let you. Always injoy your videos, your last three on tilt casing probably watched 20 times each, looking and learning in detail. Greatly appreciate your work and insights.
Brad, No, there is no flat spot on the cam. There is (almost) enough friction in the system to hold the lid up safter I have raised and swung it aside, but sometimes it does sort of slowly creep down to rest on the furnace edge. This does not seem to be any sort of problem provided I remember to raise it back up before swinging it closed again. One important thing that I notice many forget is to have stop to swing it closed against. This is the second lid that I have had. The first was constructed with the furnace in about 1975 and made from the same material - Thermocast 165 - a castable refractory able to be used up to 1650 deg C. The furnace lining itself is still in useable condition after what must be thousands of melts including hundreds of blisteringly hot aluminium bronze ones. However slowly and over many years with much use this original lid suffered from mechanical damage particularly around the central hole. I was given the existing top about 25 years ago and it is a proper manufactured furnace top complete with the central hole. It is one piece and made from the same material as good quality fire bricks. It was way too big in od so I had to cut it down. I gave no idea what it weighs but I do know it is heavy.....Martin. Ps, thanks for all those views..
Great video Martin, can venting with a thin wire reduce the Rat Tail effect. Ive had a similar finish on large flat faces in my castings and was woundering if venting abit more would help all the best
Woodsman, Randall, Yes venting with a fine wire (I use a 1/2 mm wire) can help as can coarser sand, more binder - particularly Western(sodium) bentonite, lower moisture in sand, things that soften and give the sand somewhere to go when it expands e.g. wood flour corn flour or coal dust. Use of non silica sands at least as a facing - olivine zircon and chromite. Large flat horizontal faces are the worst! Try breaking them up with a shallow cross hatch pattern. Some sands are very prone to this problem, sadly mine is one of them!.... Martin
Hi can you please tell me 1. what powder is that you put on the feeder ? 2. what does it do ? 3. why don't you put it on the gate / sprue ? Great videos I have leant so much Thanks .
Stuart, The powder I put on the feeders is called "Ferrux NF" it is an exothermic powder made by "Foseco". Its job is to catch fire and generate a lot of heat, this keeps the metal in the feeder liquid for longer so it is better able to provide liquid feed metal to the solidifying casting underneath. Things like the gates, sprue, and any vents have their own purposes which requires them to be relatively small - thus they will not stay liquid for anywhere near long enough to provide feed metal for the casting and putting exothermic on them would simply be a waste.... Martin
Hi Martin Enjoying your Explanation of molding. Could you explain how to heat treat. I think aluminum heads is Made from 556, and I have a set o like to try to Re harden.
Mr.T The heat treatment that I use is what is called a T5 process. It is an ageing process where the castings are held at a moderate temperature (aged) for about 8 hours in a fan forced electric oven, then they are allowed to cool naturally. I use a temperature of 165 deg C but 225 deg C is probably more commonly used (for the 356 alloy) Once the process has been done any attempt to redo it will be additive and it is a process that "goes over the top" and resoftens if it is carried on for too long. I am unfamiliar with 556 alloy (is the terminology correct?). I assume that you have carried out some welding which will of course have softened the heads but to re harden you would have to adopt a T6 process and this is beyond all but those with very, very good equipment as it entails holding the casting at very close to its melting point for 16 hours then water (or air blast) quenching followed by an ageing process. You would have to have this done commercially and you would need to know exactly what alloy you are dealing with. I would speak to someone who welds heads professionally and see what they do re any rehardening.... Martin
@@olfoundryman8418 Hi Martin Thanks for answering my question I missed quoted the martial it is 356, and I do have some welding I have to do on them, but the costumer I built a new set for had run the motor out of water 2 times, and the heads became so soft the they would cold flow while torqueing the motor up. Thanks Randy
Randy, "So soft they flow" Oh dear! The only way they can be recovered is to go right through a T6 process but at this involves holding about 10 degrees C below the melting point for 12 to 16 hours and the chances of distortion are well- there are no chances - It WILL distort and probably badly. It will all have to be re-machined and new guides and seats fitted, oversize ones of course as where they fit will have to be cleaned up. In short an impossible task - sell the heads to a scarp metal dealer and get some new ones and tell the customer to check the water from time to time. Sorry, but I see this as a non recoverable situation. 356 is not usually used for cylinder heads - wheels and general castings but heads would be unusual....Martin
Thanks martin That means I have to send them back to brodix, there the company that has them casted and sells them. They offer welding, and reheat treating.
I have a very odd shaped alum part that i need to fix. Which means make a cast copy of. Its rather small with high detail. I think I need to do a 2pc mold, with 1/2 the part in one side, and the other 1/2 in the other side of the mold. but I can't figure out how to make it work, as everyone always lays the part to be copied down into the box 1st, then flips. The issue I have, is this part has pieces that sit below the sand line when doing that. So it needs to be done in halves but casted as one piece. Do you have a video showing how to do that? Thanks
James, It’s a bit hard to work out from your description - can you send a photo to olfoundryman@gmail.com Most of the stuff shown on YT is with things that are either flat on one side or use split patterns so I can understand your confusion. I will have a look and see what of my videos (if any) show what you are looking for. Hmm, most of my work is either with flat one side stuff or with split patterns or has an odd side already made but try these two videos - they should give you the idea. th-cam.com/video/_2N31BxsZVU/w-d-xo.html th-cam.com/video/V_wLWRkrZ8Q/w-d-xo.html …..Martin
Mr. greens, Yes, the alloy (356) is weldable and I could have got a friend to do it for me as I do not have the facilities myself but it would be quicker (for me) to recast particularly at the moment when we are in virus lockdown and we are all supposed to stay at home .😢.. Martin
@@olfoundryman8418 thanks for your reply. I use diesel for the first 10ish minutes, then switch to WVO. The tight fit of A90 and walls got me wondering. Thanks.
Dennis, Years ago I tried waste motor oil. Problem was that half the time a 4 gallon tin contained 2 gallons of water 1 gallon of an ugly grey sludge and maybe 1 gallon of burnable fuel -the mess of sorting it out and disposing of the un-burnables was a real hassle. I did not have time for the mess of it all so I just buy diesel from the local service station way cheaper than gas and really a fairly minor cost.... Martin
Martin, Thank You for this series of highly informative videos on casting boxes. I doubt very many people who have never cast an ingot much less an actual patterned part would realize much less understand the importance of quality casting box. I am just dabbling with casting and have paid good money to take classes about casting and have learned far less than listening and watching videos. StaySafe and StayHealthy PS I about sprayed my screen with tea with your crack about polishing turds. The thing that amazes me is the number of people who roam this planet we call home that go Ape-Sh*t nuts over shiny turds. The one thing I have noticed is the shiny turd lovers generally don't know sh*t form Shinola which might explain the toilet paper hoarders.
gull, I reckon that if you have seen one polished turd you have seen them all, It is a sad fact that much of what passes for foundry "knowledge" is based on old technology and while well meant is just plain wrong - new books just copy old books. However John Campbell's work is a breath of fresh air and is very much worth studying... Martin
Dennis, Rubbing alcohol? what use is that - you can't drink it! And I don't care how available it is you can keep the "spotty" toiled paper to yourself (just what are the spots).😊... Martin
Dennis, Yeah I know re the rubbing alcohol. Locally many of the brands of hand sanitizer are in fact ethyl alcohol with a thickener. How do you make use it for comfort when its hot because its often well above 30 deg C here (we have hit 47! but several days above 40 is a summer feature During the toilet paper run (no pun intended) six months supply was sold in 3 weeks -where did it all go? I had a friend with that illness if I have guessed right and it drove the poor fellow nuts. - you have my sympathies... Martin
Kursor, I regard ingots as 1: The way I buy my metal 2: A convenient shape in which to cast that little bit extra at the end of a casting run. To me there is absolutely no point in putting a lot of effort into polishing them as they are only destined to be melted down 😊. I note too that many of the polished ingots one sees are a bit ordinary anyway - copper ingots, for example, that rise like a loaf of bread when they solidify because the metal has been very badly melted and is full of gas. But I guess it really boils down to the difference between making a useful casting and a shelf ornament 😊... Martin
@@olfoundryman8418 it was a joke but as You said for many IT can be nice shelf decoration;) I sent @ to You with my castings surface problem. Can You check that?
Thank you for the fabulously informative videos! You have answered so many of my questions already and I am endlessly grateful. I do have a question as a fledgling metallurgy nerd though. What aluminum alloys do you normally use? I'm very curious.
Zemyn, I am glad that you found the video to be of use, I use 4 different aluminium alloys. The one I use most is what we call 601 the Americans call it 356, the British LM 25. For mainly gravity die work I use what we call 401 not sure what the Americans call it but it is a eutectic aluminium silicon alloy containing 12% silicon and (apart from the aluminium) nothing else of significance. The British call it LM 6. I also use a piston alloy we call AA319, (US 336, British LM 13) and what we call 701 (British DTD5008). Hope this helps.... Martin
@@olfoundryman8418 - All of your videos have been INCREDIBLY helpful. My casting has improved massively in the couple days since I found your channel. Love A356. Having some issues, of course, with 6061 scrap that I have left over from other projects. Thinking of building some of your boxes with that. Thanks for sharing your vast experience. You've already changed at least my life for the better.
Thomas, No I have not tried and it would be a difficult thing to do as looking at the Ellingham diagram very few elements have a more rapacious appetite for oxygen than aluminium, Lithium, magnesium, and calcium are about it and probably only calcium sufficiently more oxygen hungry to reliably reduce Al2O3 to Al. The resulting Al would likely be contaminated with residual oxide plus unused calcium and calcium oxide - i.e. it would not be of much use. The only realistic (?) way would be to dissolve it all up in NaOH and go through the (same) electrolytic refining process originally used to produce the aluminium in the first place.... Martin
Olfoundryman yes that is what I was thinking. Then getting it hot and passing a current thru it to reduce the Al2O3 to Al OH3 to AL But I think it to expensive to bother. I think you are great!
Dennis, Yes, Cryolite is used as part of the molten salt electrolyte in the extraction of the aluminium and this would follow the NaOH dissolution type process. Your addition to the flux is a wise move as the standard "lite salt" flux - basically a 50:50 mix of sodium and potassium chlorides will not have much effect on aluminium oxide - you need a fluoride to attack the oxide and Croylite (sodium aluminium fluoride) is an excellent choice, but the fluorides of sodium potassium calcium and aluminium can be used too. Somewhere I have an article on fluxes for aluminium and I will see if IO can find it (we might be that lucky!). Ceramics stores are a wonderful source of all sorts of useful supplies.... Martin
Olfoundryman What about a DC electric current passed thru the molten aluminum with the ALUMINUM OXIDE and cryolite floating ON THE TOP? The fluorite is not used up in the reaction it’s just an adjuvant.
ShEtland, The coating I use on my ladles, thermocouple sheaths, and also on my degassing lance is "Hardcoat BN" it is made by ZYP coatings in the US. I re-coat everything everyday. The one thermocoupe has now lasted over 5 years and is at times immersed in the molten aluminium for several hours. I am fussy with the ladles being sure to clean off ALL aluminium before re-coating. The coat is less successful on the degassing lance as the bubbles rising up seem to disturb the coat sometimes and the metal of the lance gets attacked . When this happens I make sure to cut any attacked areas back to unattached metal before re-coating. There are a couple of problems with this coat - it is limited to 900 deg C so its no good for copper base alloys - and it is very expensive , roughly $200 per US gallon but I think you can buy it in 1 pint containers (check with ZYP) and it certainly is the best I have ever used.... Martin
G'day.. I realy like your work and I'm wondering if its possible if I could contact you for a bit of advice on a project im trying to do but I'm not sure if my plans are right. Cheers Mike.
What do you use for your flux and exotherm stuff? Also, are steel crucibles bad for aluminum? I like those green 1 pound propane cylinders for camping as I get them free, and while they only last 2 castings unless I strip the paint off and coat them with 2000F paint, they heat up pretty dang fast, they hold a lot of metal for their size, and I can bend the edge to a long and sharp angle for precise pouring. Not sure if they affect anything, but I'm down to a crucible for brass and a crucible for copper, and I have been too shiftless to purchase another. And, what fuel do you run?
Silicone, Flux is Coveral 11 by Foseco, Exothermic is Ferrux NF also by Foseco Steel crucibles are a very very big gigantic NO NO! They contaminate the aluminium with iron and iron is about the worst impurity to get in aluminium. Any aluminium melted in a steel crucible is only fit for burying in a hole in the backyard. I burn diesel for fuel and I use a commercial foundry furnace burner. Get rid of those scissor tongs for pouring they dangerous to use and difficult to get a good pour with. Get some decent metal, melting down junk will only make junk castings - GIGO and all that..... Martin PS, open your wallet and but a few proper crucibles preferably not those fleabay Chinese cheapies
@@olfoundryman8418 Good to know, I'll save the steel for casting stuff like lead or sling ammo then. I currently have some of those cheap ones that are just pliers with welded on wire, bought them ages ago and they work fine for my stuff so far. I cast in low volume as I run the classic barbecue tank foundry lined with ceramic wool, so I don't think I'll need to upgrade unless these tongs break. For metal, I use scrap, but separate it into 3 classes before I melt it, cast, extruded, and sketchy wire. Once that has been cast into ingots, I mark it with what it is, but then sort it by sinkage in the center, and how sharp the edges are. If I have enough of metal from one thing such as a pile of Sodastream tanks, I'll melt them on their own. I will likely buy some known alloys at some point, but my castings are decent for my purposes so far, so I am not in a hurry unless I run out of scrap. As for crucibles, I have heard good things about Morgan and Salamander crucibles, but I have gotten on fine with the cheap ones over the years. I would like to get some more in not too long as I'm getting sick of them getting all dirty and glassy. I saw somewhere that you should peel out the layer of metal in your crucible if you switch batches or alloys, but I doubt mine would do that as they are pretty thoroughly bonded. Any recommendations for crucibles?
Silicone, You might be surprised as to just how many of your casting problems wil go away when you start using known alloy in the form of bought ingots - I certainly was. I clean any skin or skull out of every crucible before each melt these skins are largely oxide and I do not want that in my next casting. I try to only use one alloy in any given crucible. If I have to change the alloy in a crucible I am very, very fussy about getting every little trace of the old alloy out. If you can not get it out when cold scrape it out immediately while still hot at the end of a pour - the more you get out hot the easier it is to get the remainder out cold later. Oh, and avoid using sticky fluxes they just make a mess of your crucibles and greatly shorten their lives. Always use either some thick cardboard, 20 plus sheets of newspaper, or even a glossy magazine under you crucible to stop it sticking to the plinth brick. Most of my crucibles are Morganite or Mars Tiegel.. Martin
Had another question, on your crucible do you use any kind of coating on the inside to make them last? And rough guess how may pours do you get out of the crucibles for aluminum?
Brad, I don't use and sore of wash on the inside of my crucibles. I did once try a zircon wash as it made it easier to clean the skull/skin out of the crucibles after every melt (something I am a bit fanatical about). It was not intended to lengthen crucible life and suspecting that it did the opposite I stopped the procedure. It is a rough guess but I believe that I get at least 100 melts from a crucible. They are still useable even after this but it's just that as a crucible gets older(with use) its thermal conductivity goes down (the graphite slowly burns out) and melting times go up too much. But note that I buy only good crucibles (expensive) not that junk on Ebay/Amazon.... Martin
Mariano, The powder is an exothermic that catches fire and helps keep the feeder liquid for longer so it is better able to feed the solidifying casting underneath. It is a commercial product called "Ferrux NF" it is made by Foseco. I do not know exactly what it contains but it would seem to be a type of thermite and thus contain aluminium powder and some sort of oxidizing agent..... Martin
Listening to you breath makes me worry that 40 years of parting dust may be about like 40 years of heavy smoking...I wonder...is there a brush on, or pour on, liquid parting agent that you could switch to?
I googled liquid parting agent for sand casting and found something called Aqua part II, from "The Hill and Griffith Company" out of Ohio (513) 921-1075 according to their website. If you try it please let us know what you think.
Jim, Bit more to this. I also did the 40 years of heavy smoking too😰 😱 gave up 15 may 1987! But at last check lungs are fine - about the best bit left! I wear the mike on my upper chest (clipped to shirt) so it "hears" every breath I take. Unfortunately I have CFS and have difficulty standing up, and staying up for 20 minute is an ordeal. The two hours on my feet to do this job was an exhausting ordeal from which I took 4 - 6 days to recover (hence the long time between videos). Because of all this my breathing is laboured as I struggle on, and I too can hear it in the videos particularly when I compare it to a video of just a few years ago. The parting agent I use is Calcium carbonate and is I believe fairly benign (I won't use talc!) However I will look into that liquid part - it does sound interesting, thank you for the tip... Martin
@@olfoundryman8418 thank you for going to the effort to let me know; am glad your lungs are still in order. Martin, thanks again for going to the trouble to make these videos...far better than any tv "star".
Jim, Thank you. And I did look into that liquid part -it seems to be some sort of dissolved wax ,the solvent for which evaporates reasonably quickly leaving a waterproof wax layer on the sand and pattern. It would be interesting to try but I am concerned that the "reasonably quickly " might not be quick enough and thus slow the process down... Martin
@@olfoundryman8418 right on... May be an option for certain circumstances....am afraid no matter what we do all doctor's lose all patients...we all succomb to mechanical deformation...and odds are no matter how careful we are it will be painful and expensive...am glad you and lucky are still well enough...your example is priceless from what I can see; it honors God's craftsmanship and gives us all a better chance to serve happily as the steward for all ever after...exactly what you and yours worked for all those years..cheers, Jim
"polishing a turd" LMAO !!! Love it. Good to see you back sir, always good to see someone who is interested in passing on his wisdom. Hope you and yours are well, always good to see what you've got to share. Thank you.
Donnie, Yep, I tend to laugh too when I see one of these "turd polishers" at work, but sadly if one looks at their stats they are the ones laughing! 😥 They have hundreds of thousands of subs and seem to make an absolute fortune from YT - no wonder they can afford the polish! Sigh - Life (and YT) are just not fair.😰 😱
We are surviving but in full virus lockdown AGAIN! … Martin
@@olfoundryman8418 But Martin you also need to feature one or two very cute dogs, having a well earned beer and dropping an ice cream container ice block on top of your freshly cast ingots or coins, then polish said items.
@@olfoundryman8418 Martin, I have to admit I watch just a few of the "shows". One has just exploded, he's a countryman of yours, I started watching him because if his Aussie humor, dumb things like a wee bit too much to drink. Dumb but funny. Another I wish like many others would try to come back, again because of his mix of sarcastic humor is "oilburner". I know, I think, why he hasn't uploaded in three years. Sad
Anyway, I have three channels I watch for the knowledge being shared. Yours is by far number one, luckygen number two, and the third I just subbed to is here close to me in the SE states. Primarily cast iron but casts very close to your tradition, "Windy Hill".
Thanks Martin, again, the lockdown is causing problems everywhere. Stay safe and stay healthy.
@CastingIron Engines like I told Martin, there's a really big difference between entertainment and knowledge. You can see the comments from people that don't know the difference between foundry, furnace, and forge. Take notice of how they prepare their flasks and how they remove their patterns.
I fill in with other professional casters why waiting on Martin and for my entertainment watch the other weekly channels. One, I won't mention, has an aluminum boat he's planning on melting. Entertainment.
Mark, Yeah, Am considering a couple of mutts named "Crucible" and Ladle" or maybe "Furnace" and Fuel" or even "Copper" and Bronze". I can manage the ice block and even a Carlton zero but I will be darned if I am going to get 5k worth of tats. Suggestions for dogs names taken (no notice of) 😊... Martin
"Full as a goog", "Polishing a turd" .... only in Australia! Thanks Martin. When I see you making a failed casting I feel slightly less inadequate. It's nice to hear the reasons behind the failures though.
Regards,
Mark
Mark, Once an Aussie always an Aussie. I like to throw a failure in now and then in order to keep your spirits up 😏😊... Martin
Dennis, Yep!... Martin
Every video you post helps us to improve our techniques. Thank you Martin
Michael, That's what I am aiming at - thank you for saying so....Martin
You have much to share, I hope youtubers notice the valuable content.
Metal, I hope so to - its why I am out there but sadly my audience is small....Martin
Martin you are an invaluable source of information. You should be knighted for your services to the casting community
Jeffrey, Thank you for saying so and while I will gladly accept any privileges that come with any knighthood I would rather that I caught up to those errant UT foundry people with 200,000 subs plus - 20 times mine - sigh life (and YT) isn't fair 😰😊.... Martin
The thing's that went wrong are good teaching tools thank you for showing them.
Have a good day.
Scruffy, A man, much wiser than I, once said to me " the man who has not made a mistake has not made anything". I do not mind showing a mistake/ failure particularly if as you say it is a learning exercise.... Martin
@@olfoundryman8418 so true if you never made a mistake you never tried. I make them more than i want live and learn.
Just watched this again and I have to say this is about as good a video as you have ever done. Going through the two failures as you did was most educational. Not that I need this knowledge, (cos I know a bloke who does this) but for those with a real interest, this must have been great.
Nigel, Sadly the bloke you know "who does this" is getting a bit passed it - you may need the knowledge yet!... Martin
Gday Martin, it is a great thing you do here as in all of your videos, showing ALL and explaining the reasons as to how when and why. Thanks Mate, John, EC Australia.
joandar1, I am glad that you found it useful... Martin
Thanks for explaining the casting defects at the end of this one Martin. As a beginner/hobbiest, it is often not clear what errors are causing rejects.
Rotary, Most people struggle to correctly identify the cause of rejects. Myth and legend abound even amongst long time professionals. However most defects are down to bad metal (wrong alloy or just contaminated metal), bad pouring technique, bad gating technique, and insufficient feeding.... Martin
I was watching another fella on TH-cam and he clearly needs to watch your videos. Thanks for the lesson and the lingo helps me remember my years living in Oz.
William, Yeah, I have noticed a few like this too 😏and I do wish that they would watch. Make a comment on his video suggesting that he does. Lingo is free of charge.😊... Martin
Fascinating to see a true master craftsman at work. Wishing you many more years to come and thx for sharing your knowledge....
J. Malte, Thanks for your comment - I wish for many more years too but we do not know what the future holds until it becomes the present....Martin
Martin, thank you for yet another very educational video. Showing and explaining the "failures" is _very_ educational. I'm looking forward to your next video!
Bob, At the start of the next video I will show the two replacement castings (made yesterday) beside the ones they replaced with explanation - the difference is amazing.... Martin
I swear, you only use exothermic, to make folks ask what it is! Love the way the camera operator is managing to apply the exothermic as well. I have seen your polishing wheel and you have polished things for me, I am sure you could polish those ingots as well as anybody. Nice to see more results from those patterns I printed, including those odd side pieces, they seem to work well. Let’s hope someone else prints them too!
Nigel, Yep, and they keep asking! The patterns worked very well and I hope that those who do print and try them for themselves have the same success - they should. But, No, I am not going in for ingot polishing and I do not care how many more subs doing it might get me - a man has his pride.... Martin
@@olfoundryman8418 If you are going to polish an ingot, at least section and etch it, so you can then talk about the pattern of the metal flow in the ingot mold. :-)
I wilton, I have sort of already done that with some sections of a few ingots to show the size of the gas porosity in them. As a metallurgist I spent many "Happy" hours polishing metallographic samples - but that did have a purpose....Martin
Another example of how "maker" videos should be made. As with most things, the deeper you get into something, the more you need to know about it and I (dare I say "we") appreciate the effort you go to. You have the teaching ability to explain the beginner stuff in a way that makes the experts think about it too. I'm still very interested to purchase whatever castings you have left over from this series and look forward to meeting you. Thanks Martin
ViScAsh, Thank you for your comment. I am not certain about the ultimate destination of any boxes I do get together but I will keep you interest in mind... Martin
@@olfoundryman8418 - Hey Martin. I was referring to the conversation we had in Part 2 about purchasing boxes you weren't going to need
@@olfoundryman8418 Martin, I hope we get to see you use these boxes at least a few times in videos, before you get rid of them (if you do).
It would be interesting to get your opinion on them as an experienced foundryman. And to see if you come up with any tips on ramming/whatever with this design.
You're more likely to know the tricks to get the best out of them than the rest of us -- that's why we're watching you, not the other way around!
ViScAsh, Yes, I remember the conversation but I have not yet decided what to do with the boxes I am making (assuming that I finish them of course). I may sell them in which case as you got in first with the offer to buy I will give you first right of refusal. But I may keep them or I may give them away as some sort of viewer giveaway. I do not know yet....Martin
dfross, I certainly will try them out but I don't think they will require any different techniques to my existing boxes - time will tell though....Martin
Man, I love your videos, they're so informative. Best casting videos on the internet, in my opinion.
Well, spread the word so that Martin gets the viewers that he deserves!
@@markfryer9880 oh, don't worry, I do!
jrucker, Its my opinion too but I have to admit to being perhaps just a little biased😏.... Martin
Mark, Great idea 😊... Martin
jrucker, Thanks... Martin
One of the few channels I look forward to watching, Thanks!!
Skip, Thanks... Martin
Thanks Martin! I learn more about casting than from any other You Tuber, "Polishing a Turd," good one!
Craig, Sadly the "turd polishers" of this world do vastly better from YT than I do - it ain't fair, but it is what it is I guess😰 😱... Martin
@@olfoundryman8418 I think it is because they wanted entertainment in the first place, come across someone that do it with a bit of showmanship and stayed a while until the fun wears off. Yours is for the craftsman and detailed to the degree that scares people off because they realize it means hard work...
Cobus, Yes, you are right. People watch YT to be entertained and not so much to actually learn anything. This very much favors the "turd polishers". However I think the truth is that it does not take any more work to do it properly than it does to do it badly - you just have to be a little fussier and exercise a little more care. Its a question of taking at least some pride in one's work. Sadly and to my extreme disappointment it seems that many are not prepared to do this. It is more a game of "he who dies with the most subs/views wins", rather than quality of the end result being the decider. As I said to Craig "it is what it is" I won't change and I doubt the "TPs" will either... Martin
@@olfoundryman8418 Lets hope you do not let your dissapointment translate into fewer or lesser videos. Very few of your calibre prepared to share like you do. Thanks for doing so.
@@cobusbrits2, Quite the reverse - my disappointment just increases my resolve to correct the bad info out there. Its just at the moment I am unwell to the point I can not make videos - very frustrating - brain is fine but body is falling to bits! Hopefully this is a temporary situation .😏 Sharing is my pleasure.....Martin
Excellent how to and troubleshooting! Thanks Martin!
S Bell, Thank you for saying so... Martin
Nice video Martin. Thanks for the part where you teach us what doesn't work! It's just as important as what does work. I'll be one of the guys making the patterns out of wood. For me it is a no brainer kind of decision. I am watching, learning and brushing up on things that I have forgotten. Time for me to start looking for sand. If I remember correctly there is a rather large deposit of Olivine sand no all that far from me. About 90kms. Might be worth taking a few plastic drums and filling them up!
Olivine sand - you lucky soul! Take the 10 ton truck and fill it up! Is is fine enough or do you have to crush it? Almost temps me to get on a plane except we are in lock-down!
... Martin
@@olfoundryman8418 It is sold as sandblasting sand all over the place. So my guess is that it is in variable size as it is a natural deposit. Might be wise to go there with some sieves and get what I need. Only problem will be that the sieve will allow all the fines through to. But I guess that is what washed sand is really all about. All I need is time. We are still in a graduated lock down. Everyone has to wear masks in public. Offices where you are all lined up like chickens are not really running yet. But the infection rate is stabilizing. Wash my hands is the way to go for all of us.
Mark, Used for sandblasting what a waste! Obviously then it is a sand deposit as against a solid rock one requiring crushing lucky lucky you. You do need some fines a one size sand is pretty useless - won't get enough strength for a start. In the size range required sieving is very slow will take weeks to sieve enough. However first you use a 1.5 mm sieve to get rid of the big useless stuff and then you use air sizing. I did this once a long while ago and it does work quite well, if you wish I can explain with diagrams etc how to do it not hard to set up just a bit messy and you need a very still day.... Martin
@@olfoundryman8418 You even wonder if I'm interested! Of course I'm interested. I was thinking about requiring fines and a upper size after I typed about washing it. Rather silly when you think of how the sand will hold a shape. If they are all graded as it would be in sandblasting sand it will never ram up and keep a formed shape. So yes please I am most interested in your explanation. You are making me wonder if it is anything like an old time seed and chaff separator. I remember working around one when I was a little munchkin.
Mark, I will reply on this via email might take me a little time though as I have to do a few drawings (scribbles) 😊... Martin
PS, seed and chaff - yes!
Thank you for sharing your experience. Especially interesting are your insights into setting up for a successful pour, e.g. temp, size and taper of the sprue, pouring basin, shape of the runners, and this time what air and gas defects look like, and permeability of the sand. Excellent stuff.
D. Jeff, I hope to have a short video out in a week or so dealing with just this aspect of making a superior casting. Sadly, my sand is not one of the more permeable and this does cause me problems although I have learnt to get around them (mainly 😊) (use of a thin vent wire.)....Martin
Dennis, I was lucky and managed to get my hands on some very stiff stainless steel wire used by surgeons to hold bones together, it is 1.25 mm diameter although the tip has worn down to about 0.5 mm. This works very well but I have used the central wire from a child's sparkler, its a bit soft and bends all to easily even if you take it from an unused sparkler (way to soft if it has been lit!). For cores where I want a really good vent I use a knitting needle about 2 to 3 mm diameter - this also helps the CO2 for curing the core get in easier.... Martin
Dennis, Well I hope there are a few mussos down here too in which case it should be available locally - get some and give it a go and let us know how you get on with it... Martin
thank you for the video, but importantly for showing the defects. It was very enlightening.
Charles, I am glad that it was of use... Martin
Thank you for your allowing us to learn.
Bill, My pleasure... Martin
Glad to see a new video from you, Martin. I love watching the pouring of the molten metal, with how controlled it is. I hope you have a great day.
Mister. I have a short video shot that I hope to release in the next week or so on just this subject. It shows how to get this control using good pouring basin and sprue design. IF it is well received I may expand on it by doing videos on filling time and sprue calculations. … MARTIN
@@olfoundryman8418 All casting information is useful at some point in time, but knowing that it exists is the most important thing!
Its good to see proper gapping of the crucible to Furnace wall looks about 30-40mm it amazes me how many people make this gap way too big! and then get poor performance from there and wonder why... joel
TheSilver, Yes, I guess the gap is about that with this crucible - it is an A 90. But I also melt using an A 6 in this furnace and it does look a littler funny! Furnaces are a little like garages, workshops, and lathes - they are never big enough and never small enough. But I figure that a big furnace will fit a small crucible while a small furnace will not fit a big crucible. But you are right, little crucible in big furnace means lots more fuel and lots more time😰.... Martin
Great video as usual. I for the first time today tried sand blasting my 3D printed item, it worked very well to smooth the surface. Something to keep in mind
caltick, Interesting, I have a sand blasting gun and will give it a try thanks... Martin
@@olfoundryman8418 You're welcome! I saw some vids on the web, one suggested blasting at a 60 degree angle. I tried it on PLA on a very hard to sand part and it worked very well, especially in preparation for a primer fill operation. I enjoy your videos and hope to see more in the future. Funny my first time talking with you, you had a pretty negative opinion pairing 3D printing with casting, I'm glad you found ways to incorporate 3D into your work.
Stay safe out there!
caltick, It sounds very interesting and I will definitely give it a try - I have a few 3D prints that defy sanding and I had given upon (hence my reservations re 3D printing for patterns). I have to say that they sure worked well enough for these box sides and the ability to print complex shapes particularly if finishing is simplified makes the idea very attractive - if only it had been around 30 years ago - sigh!.... Martin
Great vid. I always learn something from your posts, particularly on sprues and gating and the 'real' world of foundry work. All the best mate!
creast, Thank you for saying so. Sprues and pouring basins are the most important thing and in an upcoming video I go its this a bit more, stay tunned....Martin
Thanks again Martin for another excellent tutorial!
Japp, My pleasure - if you get something out of it I am well pleased.... Martin
Very nice castings Martin
Jess, Thank You.... Martin
Well done Martin and thanks for sharing what does happen, sad to say I’ve come across some casting problems today and third attempt is still not right but maybe recoverable-maybe.
Always a pleasure to watch, cheers. Peter
PGS, If you like send a photo of the problems to olfoundryman@gmail.com and I will take a look and can maybe suggest a solution.... Martin
G'day Martin, I sent you an email in response to your generous offer but you may not recognise it as me PGS , my name is Peter Stofmeel sorry for not identifying myself. Cheers
Peter, I have sent you a reply, you should have it by now - please let me know if you did not get it and I will resend... Martin
Hi, Sir, it's impressive to see you working and teaching at same time. More impressive is to see the passion with you do the job. I already saw almost all your videos wich are a great school to me and i already learn some small secrets that gave a huge change in the results for much better than i was achiving. One matter i still couldn't find with good precision in real world is about temperatures/problems. I know the melting point is 660ºC and in general the recomended temperature to poor should be around 750ºC. But i would like some more detail about the real temperature for each grade of aluminum and specially how to control that temperature. Also for experienced people like you the trained eye can read some signs about "where" is that temperature without special tools. That experience we can't find on books. Personally i deal with a big problem to control precisely temperature because i melt aluminum with an induction heater (i only melt 500gr at each time for smal pieces) and i can't use a thermocouple, once induction interfere with the metal sensor. And also with a IR thermometer, the reading are not to much precise... unless i could spent some thousands of euros in an industrial grade IR thermometer. Also could be good to listen the kind of problem we can get with too hight temperature and with too low temperatures. Hope one day you can do some video talking and showing examples about this topics like that one you did with tittle " Possibilities". So usefull that one!! Keep the good job and congratulations for share your knowladge with us. Thank you.
Paulo, To be honest I do not have much experience with measuring the temperature of molten metal in an induction furnace. My one experience was with alnico magnet alloy at around 2000 deg C. I used a Leeds and Northrup optical pyrometer model 8622 or 8621. I note that there are at least two of these for sale on eBay USA at the moment for around US$180. They are a good reliable instrument and are easy to use - I do not know but assume that they will go down as low as 750 deg C. (I would give my back teeth for one of these instruments!)
I thought that maybe the use of an MIMS type K couple might have been ok with induction as the metal sheath plus the fact that the two thermocouple wires are close together and side by side - but I do not really know.
For sure the (cheap) IR type of instrument has a big problem in that it relies on the emissivity of the metal surface. The problem here is that with aluminium in particular (and I suspect other metals as well) the emissivity varies wildly with the condition of the metal surface. If, for example, you were to take a reading of the metal after it had been sitting for a while then push the oxide on the surface aside to reveal a clean surface and immediately take another reading the two readings would likely be very different. Clearly such readings would be of no use as which one is correct? You can sometimes cheat a good reading by aiming the instrument at the crucible wall close to the molten metal - the emissivity of the crucible does not vary like that of the metal. BUT is the crucible at the same temp as the metal - with induction and say a graphite crucible that could be very debatable.
Trying to judge the metal temp by its colour as perceived by one’s eye is hopeless! The temps we are talking about are around the range at which molten aluminium first starts to glow. The problem is that the ambient light greatly effects your eyes perception of the colour of the molten metal. My experience here is to have (often) stood beside a furnace of molten aluminium at about 750 Deg C all day. I knew the metal was at 750 deg C because I had a thermocouple in it. If it was a bright sunny day outside (big open door and lots of windows to let the outside light in) the metal would look quite silver but if a cloud came over the sun or if it was a cloudy day the metal looked quite a bright red. My perception of the colour was of no value in temperature determination ☹.
If you cannot fine one of those Leeds and Northrup thingies then I suggest the following. Get a MIMS type K thermocouple preferably of fairly small diameter - they are on eBay everywhere and cheap. Repeatedly heat and cool the sheath for a bit more that the eventual immersion length to oxidise the sheath surface. Paint the surface with something like Boron Nitride Hard coat by ZYP Coatings. This material is expensive but provides the best protection against attack by molten metal. (I last paid about A$250.00 for a gallon of this material and it was one of those silly little American gallons 😊). However I believe it is possible to buy this or a similar material in a 1 pint size - see here for example www.graphitestore.com/pyro-paint-634-bn-boron-nitride-anti-oxidation-coating
Still not cheap but very good - assuming it’s as good as the ZYP product! I clean off any aluminium and reapply the hard coat at the end of every day. My current thermocouple (6mm diameter) has lasted well over five years and still going strong despite being immersed in molten aluminium for hours at a time on hundreds of occasions. Take a guess when your metal is a little on the hot side. Switch off the induction power and immerse the preheated (in a nearby gas flame for example) thermocouple in the molten metal - the reading should come up or down to a steady figure quite quickly - this is the temp of your metal. Power back on and repeat the process or wait till the temp drops to what you want then pour the casting. In time you will get to know how long the power needs to be on for to get close to the temp you need. This would be my approach.
Good luck and please let me know how you get on…. Martin
@@olfoundryman8418 Hi Sir, Thank you for your comments. Really good to listen from you. I was already looking for that pyrometer of Northrup at ebay and it really catch my eye. The price is not so big as i was thinking after read your info. Let's say... it's affordable. But i always have two concerns... First, is second hand precision instrument and always think if it is working good, and specialy is accurate and calibrated? If not.. how to fix? Who will fix?.. can be a problem. But for the price i would take the chance. The second concerne and the worst, is we are (Portuguese people) almost forbiden to import from USA. Why?? I don't know, but, everytime we import from USA, in the end the price goes up almost 3 times with taxes and import duties. It's funny, because from China is different. But i still didn't give up and i will try to find support about specs and how to use it. One question about this pyrometer: Once is optical instrument does it not suffer the same problem as IR thermometer as you explained? Well, another excellent idea you gave is about that pyro paint with boron-nitride. I have some K type thermocouple at home and one of them is rated for 1200ºC with 3mm diameter and 150mm long. And lucky i am this time, i can buy here boron-nitride pyro paint in form of aerosol can. Not the best... but enought to give a try. I also tried with another ceramic thermocouple type S to read the molten aluminum. And to do that i build a smal inox steel sleeve to protect ceramic tube once i immerse the probe on crucible. But readings was influenced by the magnetic field of induction heater because proble is also metal inside and also was very slow to reach the hight temperature of crucible. Now you gave that idea to warm up probe with a flame to equalize temp aprox and do the reading with power off of indution heater, and that, i will try next time. I am also thinking to build a small forge sized with my small crucible working on propane. In this way it will be easier to use that K-type 1200ºC thermocouple protected with boron-nitride. The best of induction heater is how fast it melts aluminum without big mess around. Easy process. But a hell to control temperature... Thank you again and keep teaching us with your huge knowlege! I am still thinking about that Northgrup optical pyrometer.... :):)
Paulo, My understanding - and I might be wrong - is that IR type temperature indicators rely on infra-red radiation from the metal being measured, as I have already mentioned the amount of this radiation varies as the thickness of the oxide film on the top of the molten metal. Instruments of the Leeds and Northrup type do not measure any radiation from the metal instead they compare the colour of the metal which is exactly corelated with its temperature with the colour of a lamp bulb type element within the machine. The lamp bulb element is within the instruments eyepiece superimposed on the view of the metal being measured and by adjusting the voltage on the element its colour is made to match that of the metal this gives a temperature reading. As you can see these are quite simple instruments - not a lot to go wrong! I guess that you could check the calibration of the instrument by taking readings of metal whose temperature is also being measured by a type K thermocouple.... Martin
Cheers Martin, take care out there
Rupert, We are now in lockdown again so there is not much "out there" allowed😊 but we are trying to stay healthy..... Martin
@@olfoundryman8418 I think your lockdown is a real one. The UK played at it and we have paid (still paying) big time
Rupert, Too little too late and badly, very badly organised - hotel quarantine for those flying in was a farce with security Guards - And I use the term very loosely - trading sex for freedom, that is if they did bother to turn up for work! Heads need to roll!.... Martin
Not good, there is talk today of a vaccine from Oxford. Just hope it works. Just hope WHEN a second wave hits we are more prepared!
Packed with quality observations as always...glad you are well; hope luckygen is also doing fine.
Jim, Thank you for your comment. I am not as well as I would like and am struggling a bit with the physical side of these videos (hence the slowness of publishing). Last time I spoke to lucky he was indeed well. I hope to see him soon but with Melbourne in lock-down - again! - he would be unwise to venture the 80 or so miles to get here... Martin
As ever educational Martin
It shows the differences between our sands, finish is about the same as you have a decent fine green sand but my oil bonded shows very little expansion stress.
As ever looking forward to your next episode mate.
Andy, Yes, it does appear that Petrobond has a few advantages, one of which is lower susceptibility to these wretched expansion defects. There will be a short interlude covering another subject before I get to the next episode... Martin
Martin, one disadvantage is the smoke, not a sand for a non ventilated area.
Andy, Yes I have heard this and many do not like the "feel" or smell of it, then there is as SW pointed out the disposal problem. It also slows solidification so mechanical properties are probably a bit lower but metal will run further and thinner in it (or so I have been told).. Martin
Yes, I think it runs better, I wear gloves when handling it, it can make pulling it out of the sand to water cool a little bit of a gamble, as thick parts do stay molten so much longer. & there are pro's and con's to that.
but for me doing a lot of large thin items it works well, horses for courses I guess.
I admit it. I've polished a turd before... ;-). What PSI is the air you use when doing your molds? Love your channel. Learn a lot. Thanks.
Farm, I have a separate cheap little air regulator set at 15 PSI just for the blow gun. Even so I use the gun with care typically pointing it away from the mould when I first pull the trigger as there always seems to be an initial pulse of stronger air. I never point it at any sharp sand edges and am very careful to hold the gun a ways back with delicate stuff like text.... Martin
PS. Save your scrap for those turds - at least that way it won't get used for "proper" casting stuff 😊 (then throw the ingots away!)
@@olfoundryman8418 Thank you! I hope to make some of your molding boxes soon, and will probably do a video of it. Of course I will throw some love your way, recommending your channel in the vid. You deserve more views. Are you still planning on doing the final episode where you do the pins? You may be interested in my latest video where I try to cast a coin with some detailed small text using investment plaster, but fail many times. I'm sure you will cringe at many of my attempts. Watching you, I've learned that I need to make proper pour basins. I could sand cast it if I had a pattern with some draft, but I'm really trying to perfect my investment casting process.
Another awesome video!
Wikus, Thank you... Martin
Very good explanations!!!! Like always!
Thomas, Thank you for saying so.... Martin
Hello Martin, how are you? Can you help me? What is the name of the exothermic product placed on the still liquid metal?
PRANCHA, The exothermic compound is called "Ferrux NF" it is made by Foseco... Martin
@@olfoundryman8418 Obrigado!
I always learn so much. Thank you!
Nuts, Excellent! that's why I am here on YT... Martin
Your wing nut avatar looks like a Viking helmet.
Thanks for showing the rat tail defects. I have read about those, but good pictures of what they really look like have been hard to find. Looking forward to the machining video. I have no milling machine though - is it worth casting flask sides without one? So far all my flasks have been wooden. Good health to you and yours,
Jeff
Given that you probably have a range of wood working tools, you can probably get acceptable results using a hand file, an angle grinder and an orbital sander. Keeping the file, any sanding discs and sand paper solely for use with aluminium will also prevent cross contamination from other metals. As an example I have a file dedicated to use with melamine iron on edging for cabinet work that is kept separate from other files.
Jeff,. The whole idea of this series on making your own boxes was that it can be done WITHOUT a milling machine or a lathe. I believe that we will end up with very usable flasks without the use of such machines. Hang in there and see what I wind up with and then decide if its for you. If you do make some I believe that like me you will never regret the effort that it takes.... Martin
Mark, Spot on, but go easy with the angle grinder and orbital sander - they can be a bit brutal.. Martin
Dennis, Yep, works well and I sometimes use the chalk used to mark lines for welding..... Martin
@@olfoundryman8418 sounds great, looking forward to it!
Good morning over there, been studying your foundry lid. I'm making my own almost the same size of yours about 2 1/2 " smaller. I was able to figure what size yours was when you said it had a A90 crucible. My question deals with the can action on the lever to rise the lid. It seems that you have to rest the lid on the edge when it swung out the way to get to the crucible. Do you have a flat spot on the cam so it does have to ride on the refractory of the lid. On my lid which is close to the same size as yours it weighs right at 175 pounds. Curious how long has this lid let you. Always injoy your videos, your last three on tilt casing probably watched 20 times each, looking and learning in detail. Greatly appreciate your work and insights.
Brad, No, there is no flat spot on the cam. There is (almost) enough friction in the system to hold the lid up safter I have raised and swung it aside, but sometimes it does sort of slowly creep down to rest on the furnace edge. This does not seem to be any sort of problem provided I remember to raise it back up before swinging it closed again. One important thing that I notice many forget is to have stop to swing it closed against.
This is the second lid that I have had. The first was constructed with the furnace in about 1975 and made from the same material - Thermocast 165 - a castable refractory able to be used up to 1650 deg C. The furnace lining itself is still in useable condition after what must be thousands of melts including hundreds of blisteringly hot aluminium bronze ones. However slowly and over many years with much use this original lid suffered from mechanical damage particularly around the central hole. I was given the existing top about 25 years ago and it is a proper manufactured furnace top complete with the central hole. It is one piece and made from the same material as good quality fire bricks. It was way too big in od so I had to cut it down. I gave no idea what it weighs but I do know it is heavy.....Martin.
Ps, thanks for all those views..
Great video Martin, can venting with a thin wire reduce the Rat Tail effect. Ive had a similar finish on large flat faces in my castings and was woundering if venting abit more would help
all the best
I was wondering the same thing.
Woodsman, Randall, Yes venting with a fine wire (I use a 1/2 mm wire) can help as can coarser sand, more binder - particularly Western(sodium) bentonite, lower moisture in sand, things that soften and give the sand somewhere to go when it expands e.g. wood flour corn flour or coal dust. Use of non silica sands at least as a facing - olivine zircon and chromite. Large flat horizontal faces are the worst! Try breaking them up with a shallow cross hatch pattern. Some sands are very prone to this problem, sadly mine is one of them!.... Martin
Woodsman, Randall, Oops, mistake the vent wire I use is actually 1.25 mm although tip has been worn down by the sand to about 0.5 mm... Martin
@@olfoundryman8418 Cheers Martin that explains why I was struggling to find a wire .5mm stiff enough for the job. Many thanks again
Hi can you please tell me 1. what powder is that you put on the feeder ? 2. what does it do ? 3. why don't you put it on the gate / sprue ? Great videos I have leant so much Thanks .
Stuart, The powder I put on the feeders is called "Ferrux NF" it is an exothermic powder made by "Foseco". Its job is to catch fire and generate a lot of heat, this keeps the metal in the feeder liquid for longer so it is better able to provide liquid feed metal to the solidifying casting underneath. Things like the gates, sprue, and any vents have their own purposes which requires them to be relatively small - thus they will not stay liquid for anywhere near long enough to provide feed metal for the casting and putting exothermic on them would simply be a waste.... Martin
@@olfoundryman8418 Thanks Martin
Hi Martin
Enjoying your Explanation of molding.
Could you explain how to heat treat.
I think aluminum heads is Made from 556, and I have a set o like to try to Re harden.
Mr.T The heat treatment that I use is what is called a T5 process. It is an ageing process where the castings are held at a moderate temperature (aged) for about 8 hours in a fan forced electric oven, then they are allowed to cool naturally. I use a temperature of 165 deg C but 225 deg C is probably more commonly used (for the 356 alloy) Once the process has been done any attempt to redo it will be additive and it is a process that "goes over the top" and resoftens if it is carried on for too long. I am unfamiliar with 556 alloy (is the terminology correct?). I assume that you have carried out some welding which will of course have softened the heads but to re harden you would have to adopt a T6 process and this is beyond all but those with very, very good equipment as it entails holding the casting at very close to its melting point for 16 hours then water (or air blast) quenching followed by an ageing process. You would have to have this done commercially and you would need to know exactly what alloy you are dealing with. I would speak to someone who welds heads professionally and see what they do re any rehardening.... Martin
@@olfoundryman8418
Hi Martin
Thanks for answering my question
I missed quoted the martial it is 356, and I do have some welding I have to do on them, but the costumer I built a new set for had run the motor out of water 2 times, and the heads became so soft the they would cold flow while torqueing the motor up.
Thanks
Randy
Randy, "So soft they flow" Oh dear! The only way they can be recovered is to go right through a T6 process but at this involves holding about 10 degrees C below the melting point for 12 to 16 hours and the chances of distortion are well- there are no chances - It WILL distort and probably badly. It will all have to be re-machined and new guides and seats fitted, oversize ones of course as where they fit will have to be cleaned up. In short an impossible task - sell the heads to a scarp metal dealer and get some new ones and tell the customer to check the water from time to time. Sorry, but I see this as a non recoverable situation. 356 is not usually used for cylinder heads - wheels and general castings but heads would be unusual....Martin
Thanks martin
That means I have to send them back to brodix, there the company that has them casted and sells them. They offer welding, and reheat treating.
Mr T, Be interesting to see how they go with one so badly softened.... Martin
I have a very odd shaped alum part that i need to fix. Which means make a cast copy of. Its rather small with high detail. I think I need to do a 2pc mold, with 1/2 the part in one side, and the other 1/2 in the other side of the mold. but I can't figure out how to make it work, as everyone always lays the part to be copied down into the box 1st, then flips. The issue I have, is this part has pieces that sit below the sand line when doing that. So it needs to be done in halves but casted as one piece. Do you have a video showing how to do that?
Thanks
James, It’s a bit hard to work out from your description - can you send a photo to olfoundryman@gmail.com Most of the stuff shown on YT is with things that are either flat on one side or use split patterns so I can understand your confusion. I will have a look and see what of my videos (if any) show what you are looking for.
Hmm, most of my work is either with flat one side stuff or with split patterns or has an odd side already made but try these two videos - they should give you the idea.
th-cam.com/video/_2N31BxsZVU/w-d-xo.html
th-cam.com/video/V_wLWRkrZ8Q/w-d-xo.html
…..Martin
Could you weld the defects and clean it up that way?
Mr. greens, Yes, the alloy (356) is weldable and I could have got a friend to do it for me as I do not have the facilities myself but it would be quicker (for me) to recast particularly at the moment when we are in virus lockdown and we are all supposed to stay at home .😢.. Martin
Martin, what type of fuel are you using in your furnace?
OMM, Diesel - way cleaner than waste oils and about 1/2 to 1/3 the price of LPG.... Martin
@@olfoundryman8418 thanks for your reply. I use diesel for the first 10ish minutes, then switch to WVO. The tight fit of A90 and walls got me wondering. Thanks.
Dennis, Years ago I tried waste motor oil. Problem was that half the time a 4 gallon tin contained 2 gallons of water 1 gallon of an ugly grey sludge and maybe 1 gallon of burnable fuel -the mess of sorting it out and disposing of the un-burnables was a real hassle. I did not have time for the mess of it all so I just buy diesel from the local service station way cheaper than gas and really a fairly minor cost.... Martin
Martin, Thank You for this series of highly informative videos on casting boxes. I doubt very many people who have never cast an ingot much less an actual patterned part would realize much less understand the importance of quality casting box. I am just dabbling with casting and have paid good money to take classes about casting and have learned far less than listening and watching videos. StaySafe and StayHealthy
PS I about sprayed my screen with tea with your crack about polishing turds. The thing that amazes me is the number of people who roam this planet we call home that go Ape-Sh*t nuts over shiny turds. The one thing I have noticed is the shiny turd lovers generally don't know sh*t form Shinola which might explain the toilet paper hoarders.
Yeah, and Melbourne is back in Lockdown again and the toilet paper panic buyers have gone crazy again. :((
gull, I reckon that if you have seen one polished turd you have seen them all, It is a sad fact that much of what passes for foundry "knowledge" is based on old technology and while well meant is just plain wrong - new books just copy old books. However John Campbell's work is a breath of fresh air and is very much worth studying... Martin
Mark, What the hell do they do with all the toiled paper ?.... Martin
Dennis, Rubbing alcohol? what use is that - you can't drink it! And I don't care how available it is you can keep the "spotty" toiled paper to yourself (just what are the spots).😊... Martin
Dennis, Yeah I know re the rubbing alcohol. Locally many of the brands of hand sanitizer are in fact ethyl alcohol with a thickener.
How do you make use it for comfort when its hot because its often well above 30 deg C here (we have hit 47! but several days above 40 is a summer feature
During the toilet paper run (no pun intended) six months supply was sold in 3 weeks -where did it all go? I had a friend with that illness if I have guessed right and it drove the poor fellow nuts. - you have my sympathies... Martin
Ingots with mirror polish are the best, why You dont like them;)?
Kursor, I regard ingots as 1: The way I buy my metal
2: A convenient shape in which to cast that little bit extra at the end of a casting run.
To me there is absolutely no point in putting a lot of effort into polishing them as they are only destined to be melted down 😊. I note too that many of the polished ingots one sees are a bit ordinary anyway - copper ingots, for example, that rise like a loaf of bread when they solidify because the metal has been very badly melted and is full of gas. But I guess it really boils down to the difference between making a useful casting and a shelf ornament 😊... Martin
@@olfoundryman8418 it was a joke but as You said for many IT can be nice shelf decoration;) I sent @ to You with my castings surface problem. Can You check that?
Kursor, Yeah, shes right mate, I knew it was a joke 😊 But then the whole process of melting stuff down just to make ingots is a joke 🤡... Martin
Thank you for the fabulously informative videos! You have answered so many of my questions already and I am endlessly grateful.
I do have a question as a fledgling metallurgy nerd though. What aluminum alloys do you normally use? I'm very curious.
Zemyn, I am glad that you found the video to be of use, I use 4 different aluminium alloys. The one I use most is what we call 601 the Americans call it 356, the British LM 25. For mainly gravity die work I use what we call 401 not sure what the Americans call it but it is a eutectic aluminium silicon alloy containing 12% silicon and (apart from the aluminium) nothing else of significance. The British call it LM 6. I also use a piston alloy we call AA319, (US 336, British LM 13) and what we call 701 (British DTD5008).
Hope this helps.... Martin
@@olfoundryman8418 - All of your videos have been INCREDIBLY helpful. My casting has improved massively in the couple days since I found your channel.
Love A356. Having some issues, of course, with 6061 scrap that I have left over from other projects. Thinking of building some of your boxes with that.
Thanks for sharing your vast experience. You've already changed at least my life for the better.
Zemyn, Now you know why I am opposed to using wrought alloys for casting! I am glad that I have been helpful... Martin
Have you ever tried to reduce the aluminum oxide (the waste your scooping off) back to pure aluminum???
Thomas, No I have not tried and it would be a difficult thing to do as looking at the Ellingham diagram very few elements have a more rapacious appetite for oxygen than aluminium, Lithium, magnesium, and calcium are about it and probably only calcium sufficiently more oxygen hungry to reliably reduce Al2O3 to Al. The resulting Al would likely be contaminated with residual oxide plus unused calcium and calcium oxide - i.e. it would not be of much use. The only realistic (?) way would be to dissolve it all up in NaOH and go through the (same) electrolytic refining process originally used to produce the aluminium in the first place.... Martin
Olfoundryman yes that is what I was thinking. Then getting it hot and passing a current thru it to reduce the Al2O3 to
Al OH3 to AL
But I think it to expensive to bother.
I think you are great!
Thomas, Thanks... Martin
Dennis, Yes, Cryolite is used as part of the molten salt electrolyte in the extraction of the aluminium and this would follow the NaOH dissolution type process. Your addition to the flux is a wise move as the standard "lite salt" flux - basically a 50:50 mix of sodium and potassium chlorides will not have much effect on aluminium oxide - you need a fluoride to attack the oxide and Croylite (sodium aluminium fluoride) is an excellent choice, but the fluorides of sodium potassium calcium and aluminium can be used too. Somewhere I have an article on fluxes for aluminium and I will see if IO can find it (we might be that lucky!). Ceramics stores are a wonderful source of all sorts of useful supplies.... Martin
Olfoundryman What about a DC electric current passed thru the molten aluminum with the ALUMINUM OXIDE and cryolite floating ON THE TOP? The fluorite is not used up in the reaction it’s just an adjuvant.
Can you recommend coating/paint for laddles ? Thanks
ShEtland, The coating I use on my ladles, thermocouple sheaths, and also on my degassing lance is "Hardcoat BN" it is made by ZYP coatings in the US. I re-coat everything everyday. The one thermocoupe has now lasted over 5 years and is at times immersed in the molten aluminium for several hours. I am fussy with the ladles being sure to clean off ALL aluminium before re-coating. The coat is less successful on the degassing lance as the bubbles rising up seem to disturb the coat sometimes and the metal of the lance gets attacked . When this happens I make sure to cut any attacked areas back to unattached metal before re-coating. There are a couple of problems with this coat - it is limited to 900 deg C so its no good for copper base alloys - and it is very expensive , roughly $200 per US gallon but I think you can buy it in 1 pint containers (check with ZYP) and it certainly is the best I have ever used.... Martin
G'day.. I realy like your work and I'm wondering if its possible if I could contact you for a bit of advice on a project im trying to do but I'm not sure if my plans are right.
Cheers
Mike.
Michael, You can contact me on olfoundryman@gmail.com .... Martin
What do you use for your flux and exotherm stuff?
Also, are steel crucibles bad for aluminum?
I like those green 1 pound propane cylinders for camping as I get them free, and while they only last 2 castings unless I strip the paint off and coat them with 2000F paint, they heat up pretty dang fast, they hold a lot of metal for their size, and I can bend the edge to a long and sharp angle for precise pouring. Not sure if they affect anything, but I'm down to a crucible for brass and a crucible for copper, and I have been too shiftless to purchase another.
And, what fuel do you run?
Silicone, Flux is Coveral 11 by Foseco, Exothermic is Ferrux NF also by Foseco
Steel crucibles are a very very big gigantic NO NO! They contaminate the aluminium with iron and iron is about the worst impurity to get in aluminium. Any aluminium melted in a steel crucible is only fit for burying in a hole in the backyard.
I burn diesel for fuel and I use a commercial foundry furnace burner.
Get rid of those scissor tongs for pouring they dangerous to use and difficult to get a good pour with.
Get some decent metal, melting down junk will only make junk castings - GIGO and all that..... Martin
PS, open your wallet and but a few proper crucibles preferably not those fleabay Chinese cheapies
@@olfoundryman8418 Good to know, I'll save the steel for casting stuff like lead or sling ammo then.
I currently have some of those cheap ones that are just pliers with welded on wire, bought them ages ago and they work fine for my stuff so far. I cast in low volume as I run the classic barbecue tank foundry lined with ceramic wool, so I don't think I'll need to upgrade unless these tongs break.
For metal, I use scrap, but separate it into 3 classes before I melt it, cast, extruded, and sketchy wire. Once that has been cast into ingots, I mark it with what it is, but then sort it by sinkage in the center, and how sharp the edges are. If I have enough of metal from one thing such as a pile of Sodastream tanks, I'll melt them on their own. I will likely buy some known alloys at some point, but my castings are decent for my purposes so far, so I am not in a hurry unless I run out of scrap.
As for crucibles, I have heard good things about Morgan and Salamander crucibles, but I have gotten on fine with the cheap ones over the years. I would like to get some more in not too long as I'm getting sick of them getting all dirty and glassy. I saw somewhere that you should peel out the layer of metal in your crucible if you switch batches or alloys, but I doubt mine would do that as they are pretty thoroughly bonded. Any recommendations for crucibles?
Silicone, You might be surprised as to just how many of your casting problems wil go away when you start using known alloy in the form of bought ingots - I certainly was. I clean any skin or skull out of every crucible before each melt these skins are largely oxide and I do not want that in my next casting. I try to only use one alloy in any given crucible. If I have to change the alloy in a crucible I am very, very fussy about getting every little trace of the old alloy out. If you can not get it out when cold scrape it out immediately while still hot at the end of a pour - the more you get out hot the easier it is to get the remainder out cold later. Oh, and avoid using sticky fluxes they just make a mess of your crucibles and greatly shorten their lives. Always use either some thick cardboard, 20 plus sheets of newspaper, or even a glossy magazine under you crucible to stop it sticking to the plinth brick. Most of my crucibles are Morganite or Mars Tiegel.. Martin
Had another question, on your crucible do you use any kind of coating on the inside to make them last? And rough guess how may pours do you get out of the crucibles for aluminum?
Brad, I don't use and sore of wash on the inside of my crucibles. I did once try a zircon wash as it made it easier to clean the skull/skin out of the crucibles after every melt (something I am a bit fanatical about). It was not intended to lengthen crucible life and suspecting that it did the opposite I stopped the procedure. It is a rough guess but I believe that I get at least 100 melts from a crucible. They are still useable even after this but it's just that as a crucible gets older(with use) its thermal conductivity goes down (the graphite slowly burns out) and melting times go up too much. But note that I buy only good crucibles (expensive) not that junk on Ebay/Amazon.... Martin
@@olfoundryman8418 thank you for the info
hello! One question, what does the powder that you put on the aluminum after filling the mold contain?
Mariano, The powder is an exothermic that catches fire and helps keep the feeder liquid for longer so it is better able to feed the solidifying casting underneath. It is a commercial product called "Ferrux NF" it is made by Foseco. I do not know exactly what it contains but it would seem to be a type of thermite and thus contain aluminium powder and some sort of oxidizing agent..... Martin
@@olfoundryman8418 Thank you very much, Martin, I will soon go through my materials vendor. let's see what it can offer me
What flux are you using?
SRP, I use "Coverall 11" It is made by Foseco and is a "drossing off" flux designed to just clean the dross etc. off the top of the metal.... Martin
Listening to you breath makes me worry that 40 years of parting dust may be about like 40 years of heavy smoking...I wonder...is there a brush on, or pour on, liquid parting agent that you could switch to?
I googled liquid parting agent for sand casting and found something called Aqua part II, from "The Hill and Griffith Company" out of Ohio (513) 921-1075 according to their website. If you try it please let us know what you think.
Jim, Bit more to this. I also did the 40 years of heavy smoking too😰 😱 gave up 15 may 1987! But at last check lungs are fine - about the best bit left! I wear the mike on my upper chest (clipped to shirt) so it "hears" every breath I take. Unfortunately I have CFS and have difficulty standing up, and staying up for 20 minute is an ordeal. The two hours on my feet to do this job was an exhausting ordeal from which I took 4 - 6 days to recover (hence the long time between videos). Because of all this my breathing is laboured as I struggle on, and I too can hear it in the videos particularly when I compare it to a video of just a few years ago. The parting agent I use is Calcium carbonate and is I believe fairly benign (I won't use talc!) However I will look into that liquid part - it does sound interesting, thank you for the tip... Martin
@@olfoundryman8418 thank you for going to the effort to let me know; am glad your lungs are still in order. Martin, thanks again for going to the trouble to make these videos...far better than any tv "star".
Jim, Thank you. And I did look into that liquid part -it seems to be some sort of dissolved wax ,the solvent for which evaporates reasonably quickly leaving a waterproof wax layer on the sand and pattern. It would be interesting to try but I am concerned that the "reasonably quickly " might not be quick enough and thus slow the process down... Martin
@@olfoundryman8418 right on... May be an option for certain circumstances....am afraid no matter what we do all doctor's lose all patients...we all succomb to mechanical deformation...and odds are no matter how careful we are it will be painful and expensive...am glad you and lucky are still well enough...your example is priceless from what I can see; it honors God's craftsmanship and gives us all a better chance to serve happily as the steward for all ever after...exactly what you and yours worked for all those years..cheers, Jim