Roger, It was not me - alas - I do not have that skill level. It was a friend and trained pattern maker who I managed to house train him some years ago😊 I will pass your comment on to him, I am sure he will be pleased to hear it... Martin
When I was a younger man, I lived just up the road from a man who ran a very small one man machine shop and enjoyed doing the occasional sand casting. His trick was cutting his moulds with his little mill. He's no longer around but I very much wish that I had put in the extra effort to learn anything that he might have been willing to share.
This is the most interesting ubject matter I've seen in a LONG time. Whoever would have thought CO2 and Glucose powder had parts to play in casting? Bloody fascinating. Thank you so much.
Thank you very much for sharing your wisdom, I love learning with people like you, who explain how it works and how they do it, I hope you continue to feed our minds with your magic, my sincere regards Joao
Kelley, You are very right - I have seen so much skill and knowledge vanish form the local scene as foundry after foundry close down. I guess thats why I am on YT to try and pass on what I know.. Martin
Amalgamous, I guess that over the years I have built up quite a few contacts. I know most of the people associated with the foundry industry and there are very few people left now who do this sort of work in Australia - particular the one or two off (the hard stuff! 😏) That I seem to get "stuck" with it is always interesting though and often a challenge and a learning experience - this piston sure is a case in point... Martin
Thank you so much for your compelling videos, and the skill in mold making and casting. I have only ever cast gold or silver, in the jewelry trade, 45 years ago, and my first casting attempt (which succeeded) was a mold swing about my head with the gold in the basin. But then it was good old gold, never fails to perform. However, I was the eager student of an old-time craftsman from Mexico City, DF, who had generations of skill and wisdo, distilled into practice. Lucky me. Maybe I should get into it again, but I am on in years. Thanks again.
Geo. the video are my pleasure and its a pleasure doubled when people enjoy them. My brother as a dentist and he to used the swinging on the chain mould trick properly done it dies indeed work well. Gold has the remarkable advantage that it does not oxidize - no oxide films, way fewer problems. On in years - Huh - I am 74 next month, so give it a go. Something small and light like jewellery just the thing for us old folks.. Martin
Subscribed. Love watching you work and explain the process - so much work for a part not many of us would consider would take so much to produce. Thanks for the video - look forward to part 3.
Phantom, Thanks for the sub. Yes there is a lot of work in a part like this. More than you have seen here is the pattern making including the core box. There is a lot of thought as to how to go about it we initially got it all wrong and had to do a big rethink. Part 3 which now will be 3a and 3b because otherwise it would be way to long is coming soon - next few days for part 3a I hope, a couple more for part 3b. The real work is in part 3a!.... Martin
maybe a miniature cement mixer would work for mixing up the silicate core sand, turning it over into itself, add some metal jacks/caltrops to it to cut up the lumps
War, Part 3 about a week away - just need to get it edited. I intend to make shell core moulds for the basins that way I can make lots and have them on the shelf for ever.. Martin
Lee, Soon, but now looking so long I may have to break it into part 3 a and part 3 b. If I do this I will release only a day or so apart. Working on it... Martin
Olfoundryman can you go into more detail about the glucose pulver? I didn't read about its effect on softening the breakaway properties of cores after pouring yet.
rocketry. CO2 cores have a bad reputation for poor breakdown after casting. I have had to remove them from a casting with a hammer and chisel, or a carbide drill a very slow and painful process. Also cores with breakdown this poor can cause the casting to split as it cools down and tries to contract against the core. Adding 0.5% glucose powder is quite an old trick but oddly not one very well known. It makes it possible to hose the core out with water particularly if you water quench the castings while still quite hot like I do. The difference this addition makes is absolutely amazing. I buy the glucose powder from a health food shop but someone also suggested that brewing shops should also have it. I suspect that most commercial CO2 silicate binder brews made by commercial foundry supply companies have something like the glucose powder already incorporated. I did try glucose syrup but found it too hard to incorporate properly. Just throw the glucose powder into the dry sand mix a little and then add the sodium silicate and finish mixing... Martin
Have you thought about adding a small air port to the underside of the basin mold so you can use a light blast of compressed air to help free the product? We used to do that at a fiberglass factory we worked at, it made things easier.
Mickk, Interesting thought, and it would almost certainly help. However the sand is porous so some of the air pressure may just leak away through the sand. But I will definitely give it a go as its easy to try... Martin
I had to Google "shell core." It appears to be a core that can be made hollow. Commercially made by blowing resin coated sand into a hot metal core box. The heat sets the resin and the excess is dumped out. Leaving a hollow core. Did I understand that correctly?
Larry, Yes, you have understood correctly. In some of my videos I do use this shell process. I do not blow the sand into the core box - I simply tip it in but commercially they would blow it in. The video I did on the shell core for a runway light base shows this process, it makes an excellent core...Martin
Kevin, The engine is a single cylinder with a compression ratio of about 4 to 1, it develops 10 horse power - doubt you would get much more power out of it regardless of what you did. Also the weight of the piston is important for balance reasons... Martin
Martin, thank you very much for your insightful videos, and the obvious skill and expertise you bring to each casting task. It is great to watch. It is clear that a great deal of preparation and thought goes into each successful casting and the opportunity to literally look over the shoulder of a master at work is solid gold. It is riveting stuff. A couple of questions if I may? The first is how you correctly estimate how much alloy is required for each casting? Secondly what do you use for degassing and slag removal? Thirdly I live in Australia for part of each year and would be grateful if you could point me towards good suppliers of all the consumables. Fourthly and finally, somewhere you mentioned in passing a book you found helpful. Can you easily recall the details? I can honestly say that I learn something new every time I watch your videos. I hope your health issues permit you to continue your wonderful work - and teaching. Kind regards John
John, I posted a list of possible suppliers just yesterday in response to another comment. Here is a "paste" of that reply. Fluxes, exothermic, die sprays, mould washes and release agents from Foseco they are world wide. Ceramic filters from Pyrotek Foseco and Pyrotek tend to have much the same stuff sort of. Shell sand from Beckwith Macbro Refractories, insulating boards/wool, and crucibles from Refractory and Ceramic P/L speak to Brian Weichardt mention my name he will probably charge you double😀 - no not really, he is very helpful Sieves from CMT Equipment (www.sieves.net.au) Note, I reinforced the sieve with solder to increase bond between wire and frame. Parting agent (calcium carbonate) Cast metal services Aluminium (and other)Ingot from Hayes metal Sydney Thermocouples and instruments from TC Direct - a bewildering array of stuff! Also available on "Fleabay" and probably cheaper How much metal? I guess I have just got used to eyeballing the pattern and coming up with a figure. If I have any doubt I find the volume by calculation or water immersion multiply by 2.7 and that is the weight of aluminium. I double this to allow for feeders gates etc and then make sure the crucible (I know what it will hold) has enough in it to do the required number of castings. I always weigh the casting both as out of the mould and as fettled. I record these weights on a data sheet that I keep for each job - great for future reference. Degassing, I use an argon lance of my own design. I do have a video out on this but it does need an update (when I get time 😏) Slag removal I use "Coverall 11" flux from "Foseco". Book, The best book on the subject is without doubt John Campbell's "Complete Casting Handbook". Don't buy a hard copy from Elsevier as their bookbinding is terrible and my nearly $200.00 copy began to fall apart within a few weeks. It is a hard read in places very technical. A slightly easier read is his "Casting Practice the Ten rules of casting" This book is contained within the first which has a whole lot more besides. Most other books are a bit out of date but still in at least some places usefull the difficulty is in knowing where 😏 Health issues problematic!...Martin PS I do not know why this font keeps changing colours never happened before! Maybe it will be Ok when I click "reply"
Olfoundryman wow! that was solid gold. Thank you! What is the material that bursts into flames that you put on your risers after each pour? It certainly adds drama!
Martin, I found and purchased a PDF copy of John Campbell’s book for US$ 36 from KISSLIBRARY.com great book.. all 1200+ pages! Thank you for the advice. It seems that you can also print off the pages you want if there is something that deserves special attention.
John, The material is an exothermic sort of like "thermite" it catches fire and generates a lot of heat this keeps the feeder liquid for longer so it is better able to provide feed metal to the solidifying casting underneath. It is called "Ferrux NF" and it is made by "Foseco" ... Martin
Adelan, No, both the pattern and the core box used for these pistons was made by a pattern maker and both were cut from wood. I have used 3D printed patterns for a few other jobs and I must say that I do not like them - they are weak and thus easily damaged and worst of all they have that horrid layered structure that just seems to grab the sand and make pattern withdrawal difficult - they require a lot of careful finishing if a good looking casting is to be produced. Sometimes its just easier, better, and quicker just to make the pattern using traditional methods.... Martin
Здравствуйте мастер.У меня не получается это форма. Уже второй месяц ни как не плучается. Смотрю на ваше видео отличная форма крепкая. Не скажете ли вы? Что вы добавили на песок? На 1 кг песка, сколько дабавим глина, вода или ещё что не будь житкого?
King, The sand I use is a natural moulding sand. So it already has the clay in it and all I do is add enough water to make it damp. If you are making up your own sand you need the finest sand you can get and add about 10% bentonite (by weight) to that. Mix thoroughly and then add just enough water to make it damp like a good garden soil would be. It needs to be mixed very well and may take some time to fully develop its strength. You could put it on a concrete drive and run a car over it back and forth with intermediate shoveling into a low heap. Doing this will help spread the clay over the and grains and thus help develop the sands strength. The 10% of bentonite is a starting point you can go up or down depending on how well it works. Hope this helps.... Martin
Я понял вас мастер Мартин. У меня кипить алюмини во время литьё в песочную форму. Что мне делать, что бы не кипел алюмини при литьё. Мастер Мартин спосибо вам. Моё имя Баккожа, привет из казахстана.
King, What you describe sounds like steam bubbling up between the metal and the sand - it seems to make the metal tremble and produces a rough and at times dark dull surface on the solid metal. The steam is supposed to get out through the small gaps between the sand grains in a rammed sand mould. There are three possible causes. 1. The sand is too fine or contains too much fine material so that the small gaps are closed up. Thus the steam has nowhere to go and forces itself up between the metal and the sand. 2. Th sand is too wet so there is too much steam to escape through the small gaps as it should. 3. The sand is rammed too hard this closes those small gaps up. My sand is very fine and I sometimes have this problem. I can cure it by poking a thin vent down into any area of the mould that I think might get this problem - typically around feeders and particularly around gate feeder junctions. I use about a 1 to 1.5 mm diameter wire to poke the vents into the mould. Hope this helps. Greetings from Melbourne Australia...... Martin
The complete casting handbook by Joseph Campbell is one Martin recommend to me although it's written more for the engineering side being more technical. another book is the 10 rules for casting by J Campbell (which might be an excerpt from the complete casting handbook) if you want I can get you a link to a place that's been selling a ebook pdf version of the complete casting handbook for about $30 USD
@@OldIronShops So I found the old link some people found to buy the PDF for cheap, but it sadly looks like the company has closed. here is the link although it's dead at this point digitalbookfinder.com/products/12980?variant=6794768842794 Sadly it's quite an expensive book on Amazon another option I've heard of is Scribd which has the ebook book online for paid subscribers.
I was thinking of making a pouring basin pattern something like that. I know you generally don't approve of adding head pressure extensions on top of sprues but is it worth risking a small height increase to easily get smoother cleaner basins than I can cut by hand? Beautiful patterns, and a great tip about adding glucose to the cores. I was going to try adding dextrin to improve collapsibility but I will see if I can find some glucose to try instead. Can't wait for part 3! Jeff
Jeff, A couple of points re the basin, It is actually quite easy and quick (after a little practice) to cut the basin in the top of the mould as I do at around 8 to 8.30 minutes in the Part 1 video of this series. The main think (I think!) is that the basin is vertically sided and it does not seem to matter that the bottom corners on the basin are square in fact this squareness seems to help. I have seen people cut basins that are very shallow and way too spoon shaped - definitely not a good thing! The use of a thin tube to cut out a "divot " for the basin is the easiest and quickest way. The tube I use is 30 mm diameter and I push in 30 mm deep, I then cut the sand away between this 30 mmm diameter hole and the top of the sprue leaving (very important!) a 10 mm high ridge between the basin and the sprue, the top of the ridge must be well radiused to the top of the sprue. Yes, I am very much against unnecessary head height - its just not necessary and is an evil in the way it increases turbulence during mould fill. However I am talking here about the unfortunate habit some YT casters have of extending their moulds up 100 mm or so. (The jam tin mob!) This is crazy! BUT a small increase of say 40 mm max to allow the use of a premade pouring basin is not going to cause too much of a problem and it is as you suggest a way of getting a good basin on a regular basis. Also of course coupled with a decent tapered sprue of the correct size the whole arrangement will put you miles ahead of said "jam tin mob". You can actually be very cunning with it sometimes by having the feeders vents etc not quite as high as the basin, in this way you stop pouring when the feeders are almost full and the basin drains almost completely increasing the metal yield. My "to do list" includes as a matter of some urgency the making of a little 4 cavity shell core mould to make just such basins, because the silly little funnel ones that I currently use on a lot of my work is a very poor design. The glucose powder in the core mix makes a truly amazing difference - try it. I get the glucose for a health food shop. I tried glucose syrup but could not get it to mix in properly while the powder mixes in to the dry sand very well. Part 3 in a week or so - I hope that you like it... Martin
Ron, Guy raised a similar concern to yourself regarding camera angle. He beat you by 2 hours so I answered him and sought to direct yo to my reply to him. However here is a copy of my reply to him. "Guy, I have struggled with camera angles. I have tried with the camera in all sorts of places and have not really found any to my liking. To me it looks like the right angle as it is the orientation that I see and I had jut assumed that most viewers would like that sort of view i.e. to see what I see but you are not the only person to comment on this aspect. I had not thought of people preferring to see it all from in front of me while effectively looking at me (I am a bit camera shy). In truth I am also most unhappy with the "flat" sort of perspective that the camera position gives. Many of the moulds are quite 3 dimensional and the flat view leaves a lot out. I have plans to get a second camera (when I can afford it I make nothing from YT) and mount it off to one side or something. (but it could be in front) I would value input from others out there who also feel better camera angle exists and for their ideas on it" Does this make sense?... Martin
+Olfoundryman Whatever camera angle(s) you choose, it will always miss something. While multiple camera angles helps reduce that, even if you only use 30 seconds of footage to show something in detail, you have to watch/edit twice as much footage to produce your finished video. Unless you only turn the 2nd camera on to record certain shots, in which case you lose time turning it on and off (probably with dirty/sandy hands), and doubtless you will forget to turn it on to record some critical shot. Personally, I quite like the angle you use for moulding. It's a bit different, and as you say, shows it from closer to your perspective than most angles.
@@olfoundryman8418 I think Guy may have deleted hos comment. I think tne camera angle oddness stems from the length of the boom the camera is attached to. I wasn't saying it's a bad angle, just a bit unusual, I'm not accustomed to it. 😐 If camera shyness is the issue, may I suggest a longer boom. That way, if part of your head gets into shot, it will just be the top or the back. Not that we see much else as it is now, but I do know what the tip of your nose looks like. 😄 How much draft is on that gudgeon (spelling?) boss? I know it's too late now, but those g-clamps might make serviceable handles for separating the core box halves. 👍
jkay, My "normal" core sand is a shell sand and it requires a hot (about 180 deg. C) core box mould to cure its binder, the mould has to be a reasonably good conductor of heat. The core box I had in this case was made from wood so no way it cold be used for a shell core... Martin
Charles, I don't actually set the pressure. I use a flow regulator and have about 3 to 5 litres of CO2 per minute. I make sure that there are lots of vents down into the core partly to let the CO2 into it to cure it properly and partly to let gases out during casting... Martin
Thanks for sharing, only just found your channel in these piston videos & very interesting too. Thanks for sharing, subbed to see the finished products. (Speaking of which, do you know if the machining/finishing and fitment of the pistons are to be on video too? Would be really cool to see them go through the whole process and then see the engine fire up for the first time too). Cheers, Dan.
Dan, Sadly the machining, fitting etc. is out of my hands. I do have some photos of the finished piston and they will be shown at the end of part 3b. The engine has been long ago fired up on the first piston we made nearly a year ago. The owner says it runs very sweetly and is vey happy as he tootles along at about 30 Km per hour! Thank you for the sub. I hope that you don't mind me asking, but I have recently had an absolute explosion of sub and view numbers - what bought you to my channel - just random chance or some sort of recommendation, and if so from where? The owner has said he will bring the car around so maybe I can do a minute or two of it driving around a and an under the hood look etc as a separate short video. I will see what can be arranged... Martin
Rabih, Well its big for me 😏 I did not show it finished in the video as well as I might have only realised that after they had all been used!... Martin
another thought: if the core is very hard and does not break when pouring molten metal on it, would that sand mix be usable as a refractory to make a forge?
Luke, Here I am just plain not sure! But I suspect that the difference between a momentary few minutes immersion in molten aluminium and constant exposure to that temperature and well above for hours on end might be very significant. Also there is the problem of that wretched sudden expansion that silica goes through at 530 Deg. C. I should imagine that cycling through this zone each time a furnace was fired up and later cooled down would slowly pull it apart. There are aggregates that do not suffer this problem or at least not as badly - Zircon , chromite ,olivine, chamotte - lots of them in fact and many are ingredients in traditional refractories. Also we do not know what the sodium silicate actually becomes during gassing with the CO2 - it is tempting to think it converts to sodium carbonate ???? plus some silica gel. The latter would have a high melting point but sodium carbonate melts at about 830 deg. C. All you could do is try it and see what happens but prepare to be disappointed... Martin
@@lukearts2954, no, it will desintergrate at high temps. I worked in a large steel foundry using ss cores & they completely desintergrated in the shake out & were used for makeup sand. Our bottom pour ladles used a sand nozzle & stopper, their life span was seconds to minutes, even the large ladle (70 ton) linings were 2 feet thick and lasted 8 hours or less.
@@pvtimberfaller Thank you, Ross. It's sharing of experience and knowledge like this, that makes TH-cam a great platform. You save me time, effort and money! There's obviously no need to test what has already been proven :)))
Hi, interesting putting glucose powder into teh core mix. stated to make the core easier to dig out. could I ask , why not just put less silicate into the mix??
Charles, As I said in the video a 7.5% sodium silicate addition makes for a strong core - a very strong core. I certainly could have used 5% and indeed often have in the past. Properly mixed and gassed this is quite strong too. The breakdown at 5% is still poor but you don't have to use as big a hammer on the chisel 😏.Or resort to a masonry drill as much! I have had the unfortunate experience of placing a core in a mould only to have it break as I did so and fall into the mould - not only do you loose the core - you loose the mould too - so I like to keep my cores strong to avoid that as far as possible. I think it would be a very fine balance to make a core weak enough to breakdown easily (without the glucose) yet strong enough to be handed safely. For me its just easier to make a strong core and incorporate the breakdown agent. (Note, the breakdown agent does make the core a little weaker) I use ordinary sodium silicate not a propriety brew of a formulated binder for the Silicate/ CO2 process - I suspect that some, if not most, propriety brews have a breakdown agent incorporated in them. With the glucose incorporated the core will just hose out - little if any scraping and no chiselling required - the difference is truly amazing. It does seem to help if the casting is quenched in water - the heat plus the water really seems to get stuck into softening the core... Martin
Hi Martin, Thank you. as I see it you need strength to hold the core together, but the glucose powder helps the washing out of the material after the casting. thanks again.
Charles, Yes, I think so but I suspect the heat of the casting does something to the glucose too as it almost seems to wash out in a layered way with the core a short distance from the casting washing out easiest. I guess you have to see it yo know what I mean. Try it, you will be well pleased.. Martin
Fantastic video! Really looking forward to the next one. What is the powdered release agent you are painting on the core mold, the silvery aluminium like powder, please. Cheers.
Jimmy, It is not actually a "release agent" but it seems to work for me although I suspect there are way better ones out there. It is actually a mould coat called "Mouldcote 15" it is made by Foseco and it is a chill coat used to help control solidification - usually on things like shell cores. It looks like silverfrost paint but it never quite dries and it is very messy to work with - it gets everywhere! I guess it has a sort of minute flake structure of its aluminium(?) component and that is what provides the release... Martin
probably not if you have the tools already for it. If I make my molds ( 300x200x60mm ) I have to do it otherwise it is not penetrating enough co2 in the molds. But I'll make my Co2 by mixing vinegar with baking soda. And It still takes 3 days to cure my molds. after repeating the vacuum and co2 charging cycle
Sky, Yes it can. Big foundries often reclaim their sand but its a bit of a messy process and you have to blend the reclaim in with new, typically about 50:50. I think it a bit of a bother for the hobbyist to worry about, so for the small bloke - no - not worth it. Unless you are looking for a new hobby😀 .. Martin
@@olfoundryman8418 Thank you for taking the time to answer my question👍 I've enjoyed watching your channel and have learned some great stuff. Right down to your thumb as you drawl the pattern. Find it interesting that all those times I was in a panic to fill the mold with a huge feeder was just bad practice. Keep up the great work and love those "Julia Child" over the head camera shots😃
Informative video even for a viewer who knows nothing about foundry work. Can I ask how the core mould was made? And by whom? It looks like a precision piece of aluminium to be treated very carefully.
Peter, The core mould was made by a professional pattern maker (he is a good friend). I am not exactly sure how he made it and its a pity he did not video the process as I know a lot of people are interested in pattern making techniques and there is litte on YT about it. It is actually made out of wood, it looks like aluminium because the release agent I use is a sort of aluminium paint that does not dry. All pattern equipment including core boxes needs to be treated with respect if they is to last but its not that delicate it will take reasonable handling… Martin
@@olfoundryman8418, the detailed and prompt reply was much appreciated. Wood hey? I'm just enough of a hobby woodworker to be able to appreciate the skill that went into it. Must be a very fine grained species to be cut and shaped with such precision.
TheHalloween, It is a Foseco product called "Moldcote 15". It is not actually a release agent instead it is a chill coat designed to be painted on things like shell cores principally when gravity die casting. It just happens to seem to work as a release agent but I have to put in on almost every time before ramming up a core so I guess its not really all that good! It is very like a silver-frost paint that never quite dries and in fact I have used silver-frost paint on shell cores. You could try kerosene it sort of works too...Martin
Why do they want the piston to weigh the same as the cast iron piston ? Over the last 50 years I have replaced cast iron pistons in engines such as Chevy Sixes with alloy ones because they were lighter and the thermal efficiency was better. The latest ones I did were forged pistons for a 1955 Mercedes which were 30% lighter than the originals and the engine runs very sweetly. Does the car have a Wooden Front axle?
idle quality suffers when you get the rotating/reciprocating assembly to light. i just went thru this with a vintage Porsche air cooled engine, and have seen it before. the rotating assembly in my case was almost 2 pounds lighter, between new pistons and new lightwieght con rods. theres only so much material you can remove from the crank to get it back in balance.
Mercmad, Remember this is a single cylinder engine! With a multi cylinder each piston tends to balance the other but clearly not so here. I understand that the weight had to be right or the engine would be very rough. This engine never gets much above a modern Idle - I was told about 1000rpm peak!.. Martin
@@olfoundryman8418 I am guessing here but I am thinking they wanted the piston the same weight,other wise they would be adding weights to the crank and flywheel. 1000 RPM is about average for cars of that era. A lot of stationary engines ran at 300 RPM... :-)
Booger, It sure looks like aluminium doesn't it? But no, its actually wood. The release agent that I use tomake the cores come out easier is sort of like an aluminium paint and it gives the core box that aluminium look. If it had actually been aluminium I would have used shell sand cores as they are a lot better to work with... Martin
US SAE 336. Not just soda cans will do. But what could soda cans be used for? Better to reclaim a cylinder head for certain items? I'm transfixed sir. Thank you so very much. New Zealand's Burt Munro modified his engine with such techniques. Amazing.
Gerald, No, not anti-seize It is Mo0ldecoat 15 made by Foseco. it is not actually a release agent but rather a chill coat for some sand mould surfaces it just seems to work for me as a release agent. Loctite anti-seize may well work though, but if I remember right about Loctite stuff it could be a bit expensive... Martin
Michael, I Was lucky I picked up about 50 litres many years ago but as I have almost run out so I need a supplier too! A bit of work with the great God google shows several sources within Australia, including fleabay (expensive) and a lot of pottery supply houses that carry it again not cheap - Ramshackle seems to be on to a good source. Next time I need it I will probably just go to Foseco and buy the CO2 silicate binder that they sell, it will probably already incorporate a breakdown agent - assuming of course that I can get it from them in reasonable small quantity. You could try a local foundry that uses it and offer them a handful of green for a few litres of it., It would be welcome beer money for them! Martin
Martin, thankyou for the extensive reply, really appreciated. If I find a source I will let you know. I have heard you can cook some up at home but would need to research that. Cheers Michael.
Jeffrey, I honestly do not know. I suspect that it could be, but doubt the economics - a "few off" would have to bear the cost of drawing, programming, and printing while a "lot off" would be up against the traditional gravity diecasting with its production rate of one every 11/2 to 2 minutes. 3d printing is improving all the time though, so who knows what the future holds for parts like this...Martin
@@olfoundryman8418 Good response, I was just wondering. I have done a little metal casting at home, but never any 3d printing. but metal printing will have an amazing future. Jay Leno talks about having parts for his antique cars made that way. Keep up the videos.
Jeffery, I think 3D printing to be in its infancy - will it die out, become a niche method, or will it go on to bigger things? Time will tell, my guess, somewhere between the last two... Martin
@@olfoundryman8418 Martin: It is my understanding that SpaceX is using 3d metal printers to build their rocket engines and possibly their fuel tanks, and possibly their spaceships. amazing, if true.
Stan, This issue has been discussed/commented on at some length. In the final part of this video series (part 3b) I spend some minutes towards the end of the video discussing just this issue and I refer you to that for the complete reasoning. However for the short version its quite simple I was asked to cast them so I did... Martin
Why not put the wires under the core? I would assume that would help keeping the wires in place as you stump the sand more, and might create more unity? Something else that struck me... You're a foundry man, but you don't work with metal nearly as much as you work with sand =D Of course, you need your metallurgy and your fluidomechanics knowledge up there, but your true craft ability lies in the crafting with sand...
Luke, I am not quite sure what you mean by "wires under the core" can you clarify please. Sand versus metal - Hmm, really both play a very important part and you don't tend to see the metal side of it as much in the video as the sand side, partly because the metal side is easier to control - good certified ingot, correct temperature, good degassing fluxing etc and care in handling and particularly pouring. The fluid side of things is forever an ongoing exercise in reading and learning and trying again it tens to goon more in the background just the results appear in the videos. Basically of course the sand side is just being a kid at the beach with a bucket and spade ...😏… Martin
@@olfoundryman8418 sorry, I used the wrong word... I meant the first wires you put in around 7:00 could have gone under and around the pin (so put in a bit sooner) adding an extra context between the parts under and above the pin... (I suppose if such a core breaks, it will break parallel to the bottom and at the height of that pin you put in there because of the difference in material and density) (I'm sorry, I just couldn't make out the correct word for that pin)
@@olfoundryman8418 about the bucket and spade: yes, that's certainly the feeling, but it's a kid that makes precision parts with his bucket, and the proper handling of the sand determines the level of precision, right? Just like you say: the metal part is more controllable, so it is more likely that even with less skill a decent result can be gotten on that front. But on the sand front, without skill there's no result at all...
Luke. I had thought of this and it would have worked very well indeed but I decided that it would have been to awkward to poke the sand around it. IN truth with a 7.5 silicate sand I would most likely have got away with no wires at all!... Martin
Luke, Re bucket and spade,- you are right of course but I will never be like those people who carve those fantastic sculptures out of (allegedly) beach sand they really do have skill... Martin
R.W. In the interests of improving my videos can you please specify what you mean by "hoopla"? Also can you give me a link to a MrPete video in which he does this? I have seen some of his work but not one covering this, of course he has a lot of videos so I could easily have missed it. Thank you … Martin
I am a customer of olfoundryman's and have NEVER had a quality issue. I don't think there is much amiss with his technique, as it produces good castings. As for the rest, he is trying to make a living making castings. One casting a week would not create much income.
I'm sorry, what is the point of your comment? Martin is probably the premier foundryman on TH-cam producing the finest casting out here. smallcnclathes is correct. He makes a living at this. I think the fact that he has spent the better part of 40 years perfecting his technique and skills shows remarkable patience. I defy you to find another person doing castings to have better technique.
Jmitsch, sw and smallcnc have pretty much said it. I guess that I am in the no man's land between hobbyist and professional foundry - perhaps a little closer to the latter than the former - its how I have earnt my living for many years. As such each job has to carry its own weight and hopefully make a little profit too, there are thus time constraints on production. While my intention is ever to make high integrity castings with excellent surface finish, I make no pretence of being an "artist". I have no intention of starving in a shiveringly cold garret in Paris (or anywhere else for that matter) while devoting endless hours to emulating the great Rodin. If you truly feel that my technique is "poor" could you please direct me to one of your videos that shows what you consider to be "proper technique". Several of us are waiting with some interest... Martin
![[TH] 2024 PMGC League | กลุ่มสีเหลืองวันที่ 1 | PUBG MOBILE Global Championship](http://i.ytimg.com/vi/I_FdxGT3WV4/mqdefault.jpg)
![🔴 ฟุตบอลแชมป์กีฬา 7HD แชมเปียน คัพ 2024 [รอบ 8 ทีมสุดท้าย] - ช่วงบ่าย](http://i.ytimg.com/vi/M0S_ReCIkxg/mqdefault.jpg)
10-10 to who ever made the core mold. Impressive job.
Roger, It was not me - alas - I do not have that skill level. It was a friend and trained pattern maker who I managed to house train him some years ago😊 I will pass your comment on to him, I am sure he will be pleased to hear it... Martin
When I was a younger man, I lived just up the road from a man who ran a very small one man machine shop and enjoyed doing the occasional sand casting. His trick was cutting his moulds with his little mill. He's no longer around but I very much wish that I had put in the extra effort to learn anything that he might have been willing to share.
Thank you sir!
Very much ..
You made my long journey of casting.
God bless America!
Jimmy, I am happy if I have made your journey of casting easier, Greetings from Australia.... Martin
This is the most interesting ubject matter I've seen in a LONG time. Whoever would have thought CO2 and Glucose powder had parts to play in casting? Bloody fascinating. Thank you so much.
Thank you very much for sharing your wisdom, I love learning with people like you, who explain how it works and how they do it, I hope you continue to feed our minds with your magic, my sincere regards Joao
Joao, Thank you for your comment - I will keep "feeding" as long as I can... Martin
Thanks for sharing...so important to pass these skills on to the next generation so that they don't get lost
Kelley, You are very right - I have seen so much skill and knowledge vanish form the local scene as foundry after foundry close down. I guess thats why I am on YT to try and pass on what I know.. Martin
Your name must travel for people to bring you random stuff like this. Another awesome video to learn from, thanks again!
Amalgamous, I guess that over the years I have built up quite a few contacts. I know most of the people associated with the foundry industry and there are very few people left now who do this sort of work in Australia - particular the one or two off (the hard stuff! 😏) That I seem to get "stuck" with it is always interesting though and often a challenge and a learning experience - this piston sure is a case in point... Martin
Thank you so much for your compelling videos, and the skill in mold making and casting. I have only ever cast gold or silver, in the jewelry trade, 45 years ago, and my first casting attempt (which succeeded) was a mold swing about my head with the gold in the basin. But then it was good old gold, never fails to perform. However, I was the eager student of an old-time craftsman from Mexico City, DF, who had generations of skill and wisdo, distilled into practice. Lucky me. Maybe I should get into it again, but I am on in years. Thanks again.
Geo. the video are my pleasure and its a pleasure doubled when people enjoy them. My brother as a dentist and he to used the swinging on the chain mould trick properly done it dies indeed work well. Gold has the remarkable advantage that it does not oxidize - no oxide films, way fewer problems. On in years - Huh - I am 74 next month, so give it a go. Something small and light like jewellery just the thing for us old folks.. Martin
geosutube Getting on in years?...as Winston Churchill would say: "It beats the ALTERNATIVE-!!"
Dale, Old age is a crock of crap and some days I am not to sure that Winnie was right 😏… Martin
@@olfoundryman8418 ...it beats dying YOUNG(!)
Dale, Yeh, I would agree with you there …😀 Martin
Subscribed. Love watching you work and explain the process - so much work for a part not many of us would consider would take so much to produce. Thanks for the video - look forward to part 3.
Phantom, Thanks for the sub. Yes there is a lot of work in a part like this. More than you have seen here is the pattern making including the core box. There is a lot of thought as to how to go about it we initially got it all wrong and had to do a big rethink.
Part 3 which now will be 3a and 3b because otherwise it would be way to long is coming soon - next few days for part 3a I hope, a couple more for part 3b. The real work is in part 3a!.... Martin
Nice work.... Your assistant is very patient.
Old, Women always are - well, way more so than men.😏 ..Martin
You make it look very easy
Jack, Its just practice - lots of practice..... Martin
Again a great video. Like the 'Not to shabby' line. Cheers from the UK
Rupert, Thank you and cheers from the antipodes... Martin
There's a whole lot of knowledge and experience on display here! Thanks. 👍
Tu, My pleasure to share… Martin
Again, excellent video with a lot of usable information. Thanks again.
Thomas, My pleasure... Martin
Great content for anyone interested in casting... keep it coming! Thanks.
svenp, Part 3 will be out in about a week. Glad that you like the content… Martin
maybe a miniature cement mixer would work for mixing up the silicate core sand, turning it over into itself, add some metal jacks/caltrops to it to cut up the lumps
20:14 Your release agent, you STICK with it. :)
Nice Pouring basins Martin, as you know mine are made with oil bonded sand.
looking forward to part 3.
War, Part 3 about a week away - just need to get it edited. I intend to make shell core moulds for the basins that way I can make lots and have them on the shelf for ever.. Martin
master, I watched with interest. thanks 👍
Eagerly awaiting part 3.
Lee, Soon, but now looking so long I may have to break it into part 3 a and part 3 b. If I do this I will release only a day or so apart. Working on it... Martin
This is trickier than making a souffle!
Allan, A friend, who makes a damn fine soufflé, would no doubt agree... Martin
Can't wait for part 3! Looking great
Jess, About a week away... Martin
You can feel the years of experience here....
Doug, About 60 years! .. Martin
great stuff. next gen should save all this info
Robert, Hopefully I am putting it in a form that will save at least some of it for them... Martin
Olfoundryman can you go into more detail about the glucose pulver? I didn't read about its effect on softening the breakaway properties of cores after pouring yet.
rocketry. CO2 cores have a bad reputation for poor breakdown after casting. I have had to remove them from a casting with a hammer and chisel, or a carbide drill a very slow and painful process. Also cores with breakdown this poor can cause the casting to split as it cools down and tries to contract against the core. Adding 0.5% glucose powder is quite an old trick but oddly not one very well known. It makes it possible to hose the core out with water particularly if you water quench the castings while still quite hot like I do. The difference this addition makes is absolutely amazing. I buy the glucose powder from a health food shop but someone also suggested that brewing shops should also have it. I suspect that most commercial CO2 silicate binder brews made by commercial foundry supply companies have something like the glucose powder already incorporated. I did try glucose syrup but found it too hard to incorporate properly. Just throw the glucose powder into the dry sand mix a little and then add the sodium silicate and finish mixing... Martin
Great videos, Subscribed.
Have you thought about adding a small air port to the underside of the basin mold so you can use a light blast of compressed air to help free the product? We used to do that at a fiberglass factory we worked at, it made things easier.
Mickk, Interesting thought, and it would almost certainly help. However the sand is porous so some of the air pressure may just leak away through the sand. But I will definitely give it a go as its easy to try... Martin
i love all your video !!!
Joao, That's what I like to hear, thank you... Martin
Very interesting.
B Clare, I am glad that you found it so... Martin
I had to Google "shell core." It appears to be a core that can be made hollow. Commercially made by blowing resin coated sand into a hot metal core box. The heat sets the resin and the excess is dumped out. Leaving a hollow core. Did I understand that correctly?
Larry, Yes, you have understood correctly. In some of my videos I do use this shell process. I do not blow the sand into the core box - I simply tip it in but commercially they would blow it in. The video I did on the shell core for a runway light base shows this process, it makes an excellent core...Martin
I think it would be fun to try a lightweight aluminum piston to see what higher rpm does. More power?
Kevin, The engine is a single cylinder with a compression ratio of about 4 to 1, it develops 10 horse power - doubt you would get much more power out of it regardless of what you did. Also the weight of the piston is important for balance reasons... Martin
Martin, thank you very much for your insightful videos, and the obvious skill and expertise you bring to each casting task. It is great to watch. It is clear that a great deal of preparation and thought goes into each successful casting and the opportunity to literally look over the shoulder of a master at work is solid gold. It is riveting stuff. A couple of questions if I may? The first is how you correctly estimate how much alloy is required for each casting? Secondly what do you use for degassing and slag removal? Thirdly I live in Australia for part of each year and would be grateful if you could point me towards good suppliers of all the consumables. Fourthly and finally, somewhere you mentioned in passing a book you found helpful. Can you easily recall the details? I can honestly say that I learn something new every time I watch your videos. I hope your health issues permit you to continue your wonderful work - and teaching. Kind regards John
John, I posted a list of possible suppliers just yesterday in response to another comment. Here is a "paste" of that reply.
Fluxes, exothermic, die sprays, mould washes and release agents from Foseco they are world wide.
Ceramic filters from Pyrotek
Foseco and Pyrotek tend to have much the same stuff sort of.
Shell sand from Beckwith Macbro
Refractories, insulating boards/wool, and crucibles from Refractory and Ceramic P/L speak to Brian Weichardt mention my name he will probably charge you double😀 - no not really, he is very helpful
Sieves from CMT Equipment (www.sieves.net.au) Note, I reinforced the sieve with solder to increase bond between wire and frame.
Parting agent (calcium carbonate) Cast metal services
Aluminium (and other)Ingot from Hayes metal Sydney
Thermocouples and instruments from TC Direct - a bewildering array of stuff! Also available on "Fleabay" and probably cheaper
How much metal? I guess I have just got used to eyeballing the pattern and coming up with a figure. If I have any doubt I find the volume by calculation or water immersion multiply by 2.7 and that is the weight of aluminium. I double this to allow for feeders gates etc and then make sure the crucible (I know what it will hold) has enough in it to do the required number of castings. I always weigh the casting both as out of the mould and as fettled. I record these weights on a data sheet that I keep for each job - great for future reference.
Degassing, I use an argon lance of my own design. I do have a video out on this but it does need an update (when I get time 😏)
Slag removal I use "Coverall 11" flux from "Foseco".
Book, The best book on the subject is without doubt John Campbell's "Complete Casting Handbook". Don't buy a hard copy from Elsevier as their bookbinding is terrible and my nearly $200.00 copy began to fall apart within a few weeks. It is a hard read in places very technical. A slightly easier read is his "Casting Practice the Ten rules of casting" This book is contained within the first which has a whole lot more besides. Most other books are a bit out of date but still in at least some places usefull the difficulty is in knowing where 😏 Health issues problematic!...Martin
PS I do not know why this font keeps changing colours never happened before! Maybe it will be Ok when I click "reply"
John Yep, sure enough I clicked reply and the colours vanished and the font is Ok another of those mysteries of YT I guess.. Martin
Olfoundryman wow! that was solid gold. Thank you! What is the material that bursts into flames that you put on your risers after each pour? It certainly adds drama!
Martin, I found and purchased a PDF copy of John Campbell’s book for US$ 36 from KISSLIBRARY.com great book.. all 1200+ pages! Thank you for the advice. It seems that you can also print off the pages you want if there is something that deserves special attention.
John, The material is an exothermic sort of like "thermite" it catches fire and generates a lot of heat this keeps the feeder liquid for longer so it is better able to provide feed metal to the solidifying casting underneath. It is called "Ferrux NF" and it is made by "Foseco" ... Martin
Are you using 3d printed molds?
Adelan, No, both the pattern and the core box used for these pistons was made by a pattern maker and both were cut from wood. I have used 3D printed patterns for a few other jobs and I must say that I do not like them - they are weak and thus easily damaged and worst of all they have that horrid layered structure that just seems to grab the sand and make pattern withdrawal difficult - they require a lot of careful finishing if a good looking casting is to be produced. Sometimes its just easier, better, and quicker just to make the pattern using traditional methods.... Martin
Здравствуйте мастер.У меня не получается это форма. Уже второй месяц ни как не плучается. Смотрю на ваше видео отличная форма крепкая. Не скажете ли вы? Что вы добавили на песок? На 1 кг песка, сколько дабавим глина, вода или ещё что не будь житкого?
King, The sand I use is a natural moulding sand. So it already has the clay in it and all I do is add enough water to make it damp. If you are making up your own sand you need the finest sand you can get and add about 10% bentonite (by weight) to that. Mix thoroughly and then add just enough water to make it damp like a good garden soil would be. It needs to be mixed very well and may take some time to fully develop its strength. You could put it on a concrete drive and run a car over it back and forth with intermediate shoveling into a low heap. Doing this will help spread the clay over the and grains and thus help develop the sands strength. The 10% of bentonite is a starting point you can go up or down depending on how well it works. Hope this helps.... Martin
@@olfoundryman8418 Спосибо.👍
Я понял вас мастер Мартин. У меня кипить алюмини во время литьё в песочную форму. Что мне делать, что бы не кипел алюмини при литьё. Мастер Мартин спосибо вам. Моё имя Баккожа, привет из казахстана.
King, What you describe sounds like steam bubbling up between the metal and the sand - it seems to make the metal tremble and produces a rough and at times dark dull surface on the solid metal. The steam is supposed to get out through the small gaps between the sand grains in a rammed sand mould.
There are three possible causes. 1. The sand is too fine or contains too much fine material so that the small gaps are closed up. Thus the steam has nowhere to go and forces itself up between the metal and the sand.
2. Th sand is too wet so there is too much steam to escape through the small gaps as it should.
3. The sand is rammed too hard this closes those small gaps up.
My sand is very fine and I sometimes have this problem. I can cure it by poking a thin vent down into any area of the mould that I think might get this problem - typically around feeders and particularly around gate feeder junctions. I use about a 1 to 1.5 mm diameter wire to poke the vents into the mould.
Hope this helps.
Greetings from Melbourne Australia...... Martin
you always publish in spurts lol great work like the bason mold. id like to see a list of reading material you recommend.
The complete casting handbook by Joseph Campbell is one Martin recommend to me although it's written more for the engineering side being more technical. another book is the 10 rules for casting by J Campbell (which might be an excerpt from the complete casting handbook) if you want I can get you a link to a place that's been selling a ebook pdf version of the complete casting handbook for about $30 USD
@@askquestionstrythings not a fan of pdf books but be handy none the less
@@OldIronShops So I found the old link some people found to buy the PDF for cheap, but it sadly looks like the company has closed.
here is the link although it's dead at this point
digitalbookfinder.com/products/12980?variant=6794768842794
Sadly it's quite an expensive book on Amazon
another option I've heard of is Scribd which has the ebook book online for paid subscribers.
I was thinking of making a pouring basin pattern something like that. I know you generally don't approve of adding head pressure extensions on top of sprues but is it worth risking a small height increase to easily get smoother cleaner basins than I can cut by hand?
Beautiful patterns, and a great tip about adding glucose to the cores. I was going to try adding dextrin to improve collapsibility but I will see if I can find some glucose to try instead. Can't wait for part 3!
Jeff
Jeff, A couple of points re the basin, It is actually quite easy and quick (after a little practice) to cut the basin in the top of the mould as I do at around 8 to 8.30 minutes in the Part 1 video of this series. The main think (I think!) is that the basin is vertically sided and it does not seem to matter that the bottom corners on the basin are square in fact this squareness seems to help. I have seen people cut basins that are very shallow and way too spoon shaped - definitely not a good thing! The use of a thin tube to cut out a "divot " for the basin is the easiest and quickest way. The tube I use is 30 mm diameter and I push in 30 mm deep, I then cut the sand away between this 30 mmm diameter hole and the top of the sprue leaving (very important!) a 10 mm high ridge between the basin and the sprue, the top of the ridge must be well radiused to the top of the sprue.
Yes, I am very much against unnecessary head height - its just not necessary and is an evil in the way it increases turbulence during mould fill. However I am talking here about the unfortunate habit some YT casters have of extending their moulds up 100 mm or so. (The jam tin mob!) This is crazy! BUT a small increase of say 40 mm max to allow the use of a premade pouring basin is not going to cause too much of a problem and it is as you suggest a way of getting a good basin on a regular basis. Also of course coupled with a decent tapered sprue of the correct size the whole arrangement will put you miles ahead of said "jam tin mob". You can actually be very cunning with it sometimes by having the feeders vents etc not quite as high as the basin, in this way you stop pouring when the feeders are almost full and the basin drains almost completely increasing the metal yield. My "to do list" includes as a matter of some urgency the making of a little 4 cavity shell core mould to make just such basins, because the silly little funnel ones that I currently use on a lot of my work is a very poor design.
The glucose powder in the core mix makes a truly amazing difference - try it. I get the glucose for a health food shop. I tried glucose syrup but could not get it to mix in properly while the powder mixes in to the dry sand very well. Part 3 in a week or so - I hope that you like it... Martin
@@olfoundryman8418 try glucose from a beer brewers supply.
After John Britten built his V 1000 anything is possible these days.
John, Britten - certainly a most inspiring story... Martin
That's an interesting camera angle. It's almost as if I were standing on my head. 😄 Too bad 1 core didn't turn out quite right.
Ron, Please see my reply to Guy Barry. Re the core - you can't win them all! But I had enough to get the job done.. Martin
@@olfoundryman8418 Guy Barry?
Ron, Guy raised a similar concern to yourself regarding camera angle. He beat you by 2 hours so I answered him and sought to direct yo to my reply to him. However here is a copy of my reply to him.
"Guy, I have struggled with camera angles. I have tried with the camera in all sorts of places and have not really found any to my liking. To me it looks like the right angle as it is the orientation that I see and I had jut assumed that most viewers would like that sort of view i.e. to see what I see but you are not the only person to comment on this aspect. I had not thought of people preferring to see it all from in front of me while effectively looking at me (I am a bit camera shy). In truth I am also most unhappy with the "flat" sort of perspective that the camera position gives. Many of the moulds are quite 3 dimensional and the flat view leaves a lot out. I have plans to get a second camera (when I can afford it I make nothing from YT) and mount it off to one side or something. (but it could be in front) I would value input from others out there who also feel better camera angle exists and for their ideas on it"
Does this make sense?... Martin
+Olfoundryman Whatever camera angle(s) you choose, it will always miss something. While multiple camera angles helps reduce that, even if you only use 30 seconds of footage to show something in detail, you have to watch/edit twice as much footage to produce your finished video. Unless you only turn the 2nd camera on to record certain shots, in which case you lose time turning it on and off (probably with dirty/sandy hands), and doubtless you will forget to turn it on to record some critical shot.
Personally, I quite like the angle you use for moulding. It's a bit different, and as you say, shows it from closer to your perspective than most angles.
@@olfoundryman8418 I think Guy may have deleted hos comment.
I think tne camera angle oddness stems from the length of the boom the camera is attached to. I wasn't saying it's a bad angle, just a bit unusual, I'm not accustomed to it. 😐 If camera shyness is the issue, may I suggest a longer boom. That way, if part of your head gets into shot, it will just be the top or the back. Not that we see much else as it is now, but I do know what the tip of your nose looks like. 😄
How much draft is on that gudgeon (spelling?) boss? I know it's too late now, but those g-clamps might make serviceable handles for separating the core box halves. 👍
Was wondering why you didn’t just use your normal core making sand instead of sodium silicate sand
jkay, My "normal" core sand is a shell sand and it requires a hot (about 180 deg. C) core box mould to cure its binder, the mould has to be a reasonably good conductor of heat. The core box I had in this case was made from wood so no way it cold be used for a shell core... Martin
@@olfoundryman8418 ah okay was just curious thank you for the explanation
What co2 pressure do you charge the core sand with.
Charles, I don't actually set the pressure. I use a flow regulator and have about 3 to 5 litres of CO2 per minute. I make sure that there are lots of vents down into the core partly to let the CO2 into it to cure it properly and partly to let gases out during casting... Martin
Thanks for sharing, only just found your channel in these piston videos & very interesting too. Thanks for sharing, subbed to see the finished products. (Speaking of which, do you know if the machining/finishing and fitment of the pistons are to be on video too? Would be really cool to see them go through the whole process and then see the engine fire up for the first time too). Cheers, Dan.
Dan, Sadly the machining, fitting etc. is out of my hands. I do have some photos of the finished piston and they will be shown at the end of part 3b. The engine has been long ago fired up on the first piston we made nearly a year ago. The owner says it runs very sweetly and is vey happy as he tootles along at about 30 Km per hour! Thank you for the sub.
I hope that you don't mind me asking, but I have recently had an absolute explosion of sub and view numbers - what bought you to my channel - just random chance or some sort of recommendation, and if so from where?
The owner has said he will bring the car around so maybe I can do a minute or two of it driving around a and an under the hood look etc as a separate short video. I will see what can be arranged... Martin
14:59...as Penfold would say: "AW, CRUMBS- DANGERMOUSE!!"
Dale, Indeed! But these things happen. And if I had not been on camera it would have been a bit more than "crumbs" . 😏...Martin
Olfoundryman Well...you can't win 'em ALL-!!
What is size of silica sand granules for metal foundry
3, My green sand is very fine probably about 180 AFS, the sand I use to make silicate cores is AFS 70.... Martin
Thats a big sand core
Rabih, Well its big for me 😏 I did not show it finished in the video as well as I might have only realised that after they had all been used!... Martin
another thought: if the core is very hard and does not break when pouring molten metal on it, would that sand mix be usable as a refractory to make a forge?
Luke, Here I am just plain not sure! But I suspect that the difference between a momentary few minutes immersion in molten aluminium and constant exposure to that temperature and well above for hours on end might be very significant. Also there is the problem of that wretched sudden expansion that silica goes through at 530 Deg. C. I should imagine that cycling through this zone each time a furnace was fired up and later cooled down would slowly pull it apart. There are aggregates that do not suffer this problem or at least not as badly - Zircon , chromite ,olivine, chamotte - lots of them in fact and many are ingredients in traditional refractories. Also we do not know what the sodium silicate actually becomes during gassing with the CO2 - it is tempting to think it converts to sodium carbonate ???? plus some silica gel. The latter would have a high melting point but sodium carbonate melts at about 830 deg. C. All you could do is try it and see what happens but prepare to be disappointed... Martin
@@olfoundryman8418 would make an interesting experiment. But you make some VERY good points against it :)))
@@lukearts2954, no, it will desintergrate at high temps. I worked in a large steel foundry using ss cores & they completely desintergrated in the shake out & were used for makeup sand.
Our bottom pour ladles used a sand nozzle & stopper, their life span was seconds to minutes, even the large ladle (70 ton) linings were 2 feet thick and lasted 8 hours or less.
@@pvtimberfaller Thank you, Ross. It's sharing of experience and knowledge like this, that makes TH-cam a great platform. You save me time, effort and money! There's obviously no need to test what has already been proven :)))
thanks very good video but what do you put in the silicate sand ?
Pasquier, Three things. The washed dried graded 70 AFS sand, 7.5% by weight sodium silicate, 0.5% glucose powder... Martin
Hi,
interesting putting glucose powder into teh core mix. stated to make the core easier to dig out. could I ask , why not just put less silicate into the mix??
Charles, As I said in the video a 7.5% sodium silicate addition makes for a strong core - a very strong core. I certainly could have used 5% and indeed often have in the past. Properly mixed and gassed this is quite strong too. The breakdown at 5% is still poor but you don't have to use as big a hammer on the chisel 😏.Or resort to a masonry drill as much! I have had the unfortunate experience of placing a core in a mould only to have it break as I did so and fall into the mould - not only do you loose the core - you loose the mould too - so I like to keep my cores strong to avoid that as far as possible. I think it would be a very fine balance to make a core weak enough to breakdown easily (without the glucose) yet strong enough to be handed safely. For me its just easier to make a strong core and incorporate the breakdown agent. (Note, the breakdown agent does make the core a little weaker) I use ordinary sodium silicate not a propriety brew of a formulated binder for the Silicate/ CO2 process - I suspect that some, if not most, propriety brews have a breakdown agent incorporated in them.
With the glucose incorporated the core will just hose out - little if any scraping and no chiselling required - the difference is truly amazing. It does seem to help if the casting is quenched in water - the heat plus the water really seems to get stuck into softening the core... Martin
Hi Martin,
Thank you. as I see it you need strength to hold the core together, but the glucose powder helps the washing out of the material after the casting.
thanks again.
Charles, Yes, I think so but I suspect the heat of the casting does something to the glucose too as it almost seems to wash out in a layered way with the core a short distance from the casting washing out easiest. I guess you have to see it yo know what I mean. Try it, you will be well pleased.. Martin
Fantastic video! Really looking forward to the next one. What is the powdered release agent you are painting on the core mold, the silvery aluminium like powder, please. Cheers.
Jimmy, It is not actually a "release agent" but it seems to work for me although I suspect there are way better ones out there. It is actually a mould coat called "Mouldcote 15" it is made by Foseco and it is a chill coat used to help control solidification - usually on things like shell cores. It looks like silverfrost paint but it never quite dries and it is very messy to work with - it gets everywhere! I guess it has a sort of minute flake structure of its aluminium(?) component and that is what provides the release... Martin
@@olfoundryman8418 Very many thanks Martin, that is really appreciated. If it works, it works! Cheers.
Would vacuum chamber of silicate sand parts, then backfill with CO2 be overkill?
probably not if you have the tools already for it. If I make my molds ( 300x200x60mm ) I have to do it otherwise it is not penetrating enough co2 in the molds. But I'll make my Co2 by mixing vinegar with baking soda. And It still takes 3 days to cure my molds. after repeating the vacuum and co2 charging cycle
Silly question maybe, but can the sand from silicate cores be re-used? Or is it even worth it?
Sky, Yes it can. Big foundries often reclaim their sand but its a bit of a messy process and you have to blend the reclaim in with new, typically about 50:50. I think it a bit of a bother for the hobbyist to worry about, so for the small bloke - no - not worth it. Unless you are looking for a new hobby😀 .. Martin
@@olfoundryman8418 Thank you for taking the time to answer my question👍 I've enjoyed watching your channel and have learned some great stuff. Right down to your thumb as you drawl the pattern. Find it interesting that all those times I was in a panic to fill the mold with a huge feeder was just bad practice. Keep up the great work and love those "Julia Child" over the head camera shots😃
Informative video even for a viewer who knows nothing about foundry work. Can I ask how the core mould was made? And by whom? It looks like a precision piece of aluminium to be treated very carefully.
Peter, The core mould was made by a professional pattern maker (he is a good friend). I am not exactly sure how he made it and its a pity he did not video the process as I know a lot of people are interested in pattern making techniques and there is litte on YT about it. It is actually made out of wood, it looks like aluminium because the release agent I use is a sort of aluminium paint that does not dry. All pattern equipment including core boxes needs to be treated with respect if they is to last but its not that delicate it will take reasonable handling… Martin
@@olfoundryman8418, the detailed and prompt reply was much appreciated. Wood hey? I'm just enough of a hobby woodworker to be able to appreciate the skill that went into it. Must be a very fine grained species to be cut and shaped with such precision.
what is the name of the release agent do you use?
TheHalloween, It is a Foseco product called "Moldcote 15". It is not actually a release agent instead it is a chill coat designed to be painted on things like shell cores principally when gravity die casting. It just happens to seem to work as a release agent but I have to put in on almost every time before ramming up a core so I guess its not really all that good! It is very like a silver-frost paint that never quite dries and in fact I have used silver-frost paint on shell cores. You could try kerosene it sort of works too...Martin
Why do they want the piston to weigh the same as the cast iron piston ? Over the last 50 years I have replaced cast iron pistons in engines such as Chevy Sixes with alloy ones because they were lighter and the thermal efficiency was better. The latest ones I did were forged pistons for a 1955 Mercedes which were 30% lighter than the originals and the engine runs very sweetly. Does the car have a Wooden Front axle?
idle quality suffers when you get the rotating/reciprocating assembly to light. i just went thru this with a vintage Porsche air cooled engine, and have seen it before.
the rotating assembly in my case was almost 2 pounds lighter, between new pistons and new lightwieght con rods.
theres only so much material you can remove from the crank to get it back in balance.
Mercmad, Remember this is a single cylinder engine! With a multi cylinder each piston tends to balance the other but clearly not so here. I understand that the weight had to be right or the engine would be very rough. This engine never gets much above a modern Idle - I was told about 1000rpm peak!.. Martin
@@olfoundryman8418 I am guessing here but I am thinking they wanted the piston the same weight,other wise they would be adding weights to the crank and flywheel. 1000 RPM is about average for cars of that era. A lot of stationary engines ran at 300 RPM... :-)
@@Mercmad they would need to remove weight from the crankshaft counterweight.
Is that mold made of aluminum?
Booger, It sure looks like aluminium doesn't it? But no, its actually wood. The release agent that I use tomake the cores come out easier is sort of like an aluminium paint and it gives the core box that aluminium look. If it had actually been aluminium I would have used shell sand cores as they are a lot better to work with... Martin
Yeah. I thought it's aluminium because of the color. Then I got confused when I see the bottom that looks like wood so I asked about it. Lol
Interesting, what kind of aluminum are you using for pistons?
Marty, The alloy is 336 known locally as AA319 and as LM 13 in the UK... Martin
US SAE 336. Not just soda cans will do. But what could soda cans be used for? Better to reclaim a cylinder head for certain items? I'm transfixed sir. Thank you so very much. New Zealand's Burt Munro modified his engine with such techniques. Amazing.
That release agent looks like Loctite Anti-seize. Would that be it?
Gerald, No, not anti-seize It is Mo0ldecoat 15 made by Foseco. it is not actually a release agent but rather a chill coat for some sand mould surfaces it just seems to work for me as a release agent. Loctite anti-seize may well work though, but if I remember right about Loctite stuff it could be a bit expensive... Martin
Loctite is also very hard to clean off. There are memes online about mechanics getting it all over themselves.@@olfoundryman8418
Laughin, maaaaate!
Just wondering where is the best place in Australia to get sodium silicate?
ABLE WESTCHEM (About $35.00 +gst per 5L)
Ron, Are you sure its silicon and not silica i.e. silicon dioxide (sand). With the caustic soda method they generally use pure white sand.. Martin
Ram, Can't find it on their rather strangely arranged web site so I will take your word for it . That is not too bad a price... Martin
Michael, I Was lucky I picked up about 50 litres many years ago but as I have almost run out so I need a supplier too! A bit of work with the great God google shows several sources within Australia, including fleabay (expensive) and a lot of pottery supply houses that carry it again not cheap - Ramshackle seems to be on to a good source. Next time I need it I will probably just go to Foseco and buy the CO2 silicate binder that they sell, it will probably already incorporate a breakdown agent - assuming of course that I can get it from them in reasonable small quantity. You could try a local foundry that uses it and offer them a handful of green for a few litres of it., It would be welcome beer money for them! Martin
Martin, thankyou for the extensive reply, really appreciated. If I find a source I will let you know. I have heard you can cook some up at home but would need to research that. Cheers Michael.
OMG ! What an ordeal!
Iguana, Yep, nothing good comes easy! You wait till you see part 3!.. Martin
Is it possible to make the piston with 3d metal printing?
Jeffrey, I honestly do not know. I suspect that it could be, but doubt the economics - a "few off" would have to bear the cost of drawing, programming, and printing while a "lot off" would be up against the traditional gravity diecasting with its production rate of one every 11/2 to 2 minutes. 3d printing is improving all the time though, so who knows what the future holds for parts like this...Martin
@@olfoundryman8418 Good response, I was just wondering. I have done a little metal casting at home, but never any 3d printing. but metal printing will have an amazing future. Jay Leno talks about having parts for his antique cars made that way. Keep up the videos.
Jeffery, I think 3D printing to be in its infancy - will it die out, become a niche method, or will it go on to bigger things? Time will tell, my guess, somewhere between the last two... Martin
@@olfoundryman8418 Martin: It is my understanding that SpaceX is using 3d metal printers to build their rocket engines and possibly their fuel tanks, and possibly their spaceships. amazing, if true.
🙌👏👏👏👏Showw!!!
9mm, Glad you liked it.. Martin
Part 3?
345, Coming, coming, but answering all these comments is slowing me down 😏… Martin
the piston is a simple enough shape why wasnt it just machined from a billet.
Stan, This issue has been discussed/commented on at some length. In the final part of this video series (part 3b) I spend some minutes towards the end of the video discussing just this issue and I refer you to that for the complete reasoning. However for the short version its quite simple I was asked to cast them so I did... Martin
Why not put the wires under the core? I would assume that would help keeping the wires in place as you stump the sand more, and might create more unity?
Something else that struck me... You're a foundry man, but you don't work with metal nearly as much as you work with sand =D Of course, you need your metallurgy and your fluidomechanics knowledge up there, but your true craft ability lies in the crafting with sand...
Luke, I am not quite sure what you mean by "wires under the core" can you clarify please.
Sand versus metal - Hmm, really both play a very important part and you don't tend to see the metal side of it as much in the video as the sand side, partly because the metal side is easier to control - good certified ingot, correct temperature, good degassing fluxing etc and care in handling and particularly pouring. The fluid side of things is forever an ongoing exercise in reading and learning and trying again it tens to goon more in the background just the results appear in the videos.
Basically of course the sand side is just being a kid at the beach with a bucket and spade ...😏… Martin
@@olfoundryman8418 sorry, I used the wrong word... I meant the first wires you put in around 7:00 could have gone under and around the pin (so put in a bit sooner) adding an extra context between the parts under and above the pin... (I suppose if such a core breaks, it will break parallel to the bottom and at the height of that pin you put in there because of the difference in material and density) (I'm sorry, I just couldn't make out the correct word for that pin)
@@olfoundryman8418 about the bucket and spade: yes, that's certainly the feeling, but it's a kid that makes precision parts with his bucket, and the proper handling of the sand determines the level of precision, right? Just like you say: the metal part is more controllable, so it is more likely that even with less skill a decent result can be gotten on that front. But on the sand front, without skill there's no result at all...
Luke. I had thought of this and it would have worked very well indeed but I decided that it would have been to awkward to poke the sand around it. IN truth with a 7.5 silicate sand I would most likely have got away with no wires at all!... Martin
Luke, Re bucket and spade,- you are right of course but I will never be like those people who carve those fantastic sculptures out of (allegedly) beach sand they really do have skill... Martin
Get a small cement mixer
Will, Its a plan. Z mixers work well too - but I don't do enough of this work to make it worth while... Martin
tubalcain can do this without all the hoopla!!!!!
R.W. In the interests of improving my videos can you please specify what you mean by "hoopla"?
Also can you give me a link to a MrPete video in which he does this? I have seen some of his work but not one covering this, of course he has a lot of videos so I could easily have missed it. Thank you … Martin
Ron, Thanks for your input... Martin
Poor technique working much to fast. Lots of skill little patience.
I am a customer of olfoundryman's and have NEVER had a quality issue. I don't think there is much amiss with his technique, as it produces good castings. As for the rest, he is trying to make a living making castings. One casting a week would not create much income.
I'm sorry, what is the point of your comment? Martin is probably the premier foundryman on TH-cam producing the finest casting out here. smallcnclathes is correct. He makes a living at this. I think the fact that he has spent the better part of 40 years perfecting his technique and skills shows remarkable patience. I defy you to find another person doing castings to have better technique.
Jmitsch, sw and smallcnc have pretty much said it. I guess that I am in the no man's land between hobbyist and professional foundry - perhaps a little closer to the latter than the former - its how I have earnt my living for many years. As such each job has to carry its own weight and hopefully make a little profit too, there are thus time constraints on production. While my intention is ever to make high integrity castings with excellent surface finish, I make no pretence of being an "artist". I have no intention of starving in a shiveringly cold garret in Paris (or anywhere else for that matter) while devoting endless hours to emulating the great Rodin.
If you truly feel that my technique is "poor" could you please direct me to one of your videos that shows what you consider to be "proper technique". Several of us are waiting with some interest... Martin