On looking at the video I notice that I incorrectly broke the surface 😱 while stirring the "right' way. I can only put this lamentable error down to concentrating on what I was saying rather than what I was doing - sorry about that 🙄. I hope that you can do better.. I note that some paint manufacturers are advising stirring in this "right" way. Stands to reason I guess as you do not want air whipped into your paint and you do want the bottom bought to the top and stirred in.....Martin
Mister, Absolutely! Turbulence is the enemy. This does not mean that you need the impossible target of lamella flow just that you MUST avoid breaking and folding in of the surface.... Martin
Martin I have found all of your videos helpful over the years, there are so many people on TH-cam doing it the wrong way, it amazes me how people "damage" their metal by using improper processes. There are so many ingot polishers on here and when I see those videos I scroll past. Thank you for putting up premium content.
Brent, Without doubt introducing air into metal is responsible for a very large percentage of casting defects - and without doubt its the worst thing you can do. Molten metals are very reactive and will "burn" with any air to form oxides and sometimes nitrides to the great detriment of properties... Martin
It even makes sense to have a movement that goes up and down to mix the top and bottom metals together:: bring the bottom metal up, push the top metal down. Instead of string and expecting that the metals will be agitated enough to mix.
Martin in his Element! Its like in the dancing school! Cross - up - over - down.....good to see you fresh and motivated!! Best Regards from the other side of the planet!
Thomas, Yep, nothing like a bit of old time dancing foxtrot, barn dance, modern waltz, I did them all - Oh so long ago. In fact I met my wife at Doris Jacobs (she was something of a local legend) dancing classes - true story.... Martin
Earthy. Eh, not really feeling better just struggling on. Something like this, a few minutes at a time I can manage - sometimes. Just need to get those few minutes longer... Martin
Hard to argue when you make sense. If only all the amateur foundrymen and women would watch this. Nice to see you back at the educational videos Martin. Mark
Mark, I too wish that all foundrymen both amateur and professional would watch (would do wonders for my views 😊) Many professionals are worse that a lot of hobbyists - I do not know why they are still in business. But I sure wish they would watch me rather than some of the misleading stuff out there. More vids to come Hope - a head full of ideas...Martin
Will, The wife was very loath to loan me one of those jars - she has a fair number and the were her mothers - irreplaceable now of course. She was terrified I would break it. Fortunately for my access to a warm bed I did not break it.... Martin
Martin, thank you for all the time you spend editing and piecing your videos together. I would like to ask a question which I hope is not really dumb. Is it feasible to place reinforcing steel in the mould and then pour the aluminum around it? The intention being to give it more strength.
Iafarms, Not dumb at all. I do something similar with casting aluminium around a heating element :- see here studio.th-cam.com/users/videoQ4sGl4jOQtA/edit Of course this is not for strength but it is cast in just as a steel reinforcement might be. Note that I preheat the element to make sure that the aluminium runs around it properly. I doubt that you will get any true bonding with the steel reinforcing and I am not sure how much strength increase you will get or how reliable casting to casting it might be. You might just be better producing a superior quality casting out of, say, 357 alloy and then having it properly T6 heat treated.... Martin
@@olfoundryman8418 Thank you Martin, I would only be making two, or three and stretch the third unit it fails. I had not thought about casting around a heating element. That solves another project! David
Hi Martin, I think I'd seen you possibilities video before my second attempt @ a pour so didn't stir and when I took the dross out was a lot more gentle! Thanks for all your videos and help, stay safe n well. TFS, GB :)
I had a buddy who for some perverse reason had a passion for old Skodas - I think mainly because he got them for free. We were moving an engine-transmission and we let it drop onto the ground from the tremendous height of an inch. The transmission broke cleanly into two neat pieces. The interior of the casting had uniformly the appearance of a metal aerobar. Interestingly the casting exterior finish was superb - still wondering if this was intentional, sabotage or an unhappy accident. Love the channel.
francis, I understand perverse passions for odd vehicles only too well - I have been thus afflicted most of my life. Your metal aerobar casting sounds like a pressure diecasting. These commonly have a good surface finish. But the process relies on squirting metal into a die at just about sonic velocity much air can be entrained during this process and if the die is not well designed (many are not) you get the trapped air bubbles that pressure die castings are often known for. So intentional - no, sabotage - no, unhappy and likely recurring accident - yes. I love that you love the channel.... Martin
Thanks again - really great and usable information. I love how you share the evolution of your technique with the clangers along the way. Pressure diecasting makes sense - never having seen it in action I respect your analysis. I appreciate perverse passions - I wouldn't mind a Bristol or a panhard or a Vincent - a Skoda is more a lingering STD one can do without!@@olfoundryman8418
Gafrers, Maybe not 😊! To be honest the dies dispersed into the water way to quickly - I guess they are made to do that. But I really needed something that would mix in with a little more difficulty as I had hoped to show better mixing with the "right way" as well as the more important no air introduction. Perhaps a small amount of a thick water based house paint may have been better?.... Martin
And whipping away at like it's a cup of tea also results in the vortex paradox, where the heavier material gets concentrated in the centre of the vessel at the bottom. So it's just a BAD technique all around to stir the metal like it's a cup of tea or coffee.
Lancer, Yep, but I guess its possible to stir tea (or coffee) with this down across up across down motion too 😊 but furiously round and round with the spoon, no, definitely not.... Martin
Good morning . my compliments for her foundry culture both theoretical and practical. I would like to know, if possible, how your molding sand mixture is composed. Given the excellent results of the castings she produces. Sincerely Alfio Antonini
alfio, The sand I use is a natural green sand. IT came from a quarry about 30 Km from where I live. As such it is composed of fine sand with about 15 to 20 % of a natural clay plus water.... Martin
Very nice; thanks for that. I guess it's good to try to build a better sense of what's happening to the metal at each step along the way; a feel for it. It's too easy to just take a quick intuitive approach without thinking about what's really happening!
G-day mate, catching up on a few videos at last, I will drop you a line. keep up the sweet little how to videos, think it's going to help a lot of people out.
Andy, Finally given up revving the crap out of that poor little Mazda? Front wheel drive is so damn useless up slippery hills particularly if you over do the revs😊 How many sets of front tyres did you wear out? All that smoke!!! 😱.... Martin
Ahh The MX5 is rear wheel drive Martin. No not given up, Mike has had a back op, so is out of action, I could have taken the MX on an event with someone else, but I have done that once already & as we co own the car, I felt I'd rather wait until he's fit again. last event we got through 2 tyre's, never due to wear, it's always punchers on the rock :(
Great video , I noticed you have a Mill in the background in your video , it looks like an Archdale vertical mill with a sliding head, I am asking as I have an Archdale VM30 , getting information on has proven fruitless as I am yet to get anything of use like an exploded diagram showing how it's put together , even a scanned copy of an owners manual would be of use
Allan, Thanks for your comment. I assume that you mean the mill right at the back that pretty much only the head of is visible, sorry but its a Cincinnati #2 vertical (I call her the "beast" - she weighs close to 3 t) so I can not help you with any info on your Archdale -sorry.... Martin
@@olfoundryman8418 Yes that machine you describe looked similar to my Archdale , it would be around the same weight as well, I just did a search on the model and while it has a sliding head like mine it is noticeably different to mine , I do know from others that it was made in the 1920s . I couldn't see enough to be sure of much , hanks for coming back to me
Im a machinist in the states and I have done some home aluminum casting in the past but I wasnt good at judging sprue, runner and riser sizes. I am getting ready to pour a prototype cylinder head for a pulling tractor. The one I am casting is just the size for 1 cyl. The casting will basically be a block of aluminum 6 1/2" x 7 5/8" x 5" thick with 2 cores for the intake and exhaust port. Would you have an idea of the size of the sprue , runner and the risers needed.
James, Hang on - a case of more information needed 😊. You seem to be talking about a rectangular lump of aluminium that neglecting the two port cores will weigh in at about 24 lb by the time we add about 16 Lb for feeders gates runners etc - that is a 40Lb casting. That seems very heavy for a single cylinder head.😱 So do you have a photo or drawing or even a sketch of the actual shape that you are after? You can send it to olfoundryman@gmail.com Martin
Bbuse, I believe that the spruce stick is to remove oxygen from the metal by virtue of the hydrocarbon gasses it gives off and not so much to stir it. It is a somewhat older technique and better methods are available today. To be honest I don't think too much of the method as water vapour is also given off and this can cause all sorts of problems with the metal, not to mention safety issues, pays to stand well back! Remember they start with ingots of the required alloy so no actual stirring is necessary.... Martin
Hello Martin, I'm into metal casting since two months now. I've build my own furnace and started my firts attempts to cast some simple parts from aluminium. After inplementing some of your tips - the results are getting better. Entraining of air was the biggest issue at the beginning. Since I got rid of the 'ridicoulously big pouring funnel' as you called it and reducing the diameter of the infill drastically - I was very pleased to see the first part without any visible inclusions. Thank you, very much for sharing your knowledge. I assume that the correct pouring temperature is also very important. I guess I always overheating the metal. Could you please be so kind to explain what kind of equipment you use to measure the temperature? Do you use a thermocouple? Which brand and how you protect it from the high heat?
el, Yes, there is a right way and a wrong way as with most things. The right way gives a much better chance of a good casting. Temperature is important. A max of 760 deg C is advisable for aluminium as temps above this can cause bad gas problems. I tend to pour a bit hotter than perhaps I should - most of my castings are poured at 720 to 745 deg C. I have covered the thermocouple question in another answer to you but please note that the protective wash I mentioned i.e. the BN hardcoat is only of use up to 900 eg C so it is useless for bronze..... Martin
Thank you. I've found a dipstick sensor with a copper plating which should withstand temps up to 1100°C. I'm not sure if the hot aluminium will stick to the sensor or how fast it will be corroded. www.thermagmbh.de/en/shop/product/thermocouples/dipstick-thermocouples/dipstick-thermocouple-teflon-type-k/
@@elpresidente4441 This might be better and cheaper too plus it has the instrument that gives the readout www.ebay.com.au/itm/282576231648?hash=item41cadb1ce0:g:2e0AAOSwW4hcdcDy It is also thicker so a bit more robust (maybe ) coat the end that will go into the metal with some sort of a ceramic wash like a thin layer of fireclay and sodium silicate mixture painted on and dried. Get the longest one.... Martin
Hello, I want to cast an aluminum plate (12mm thick), so I need two sides to be as parallel/flat as possible so I don't have to face it too much later (my weak cnc router would appreciate it). I will use foam and plaster for this process. My question is: Should I position the mold flat to the flask as usual, or positioning it at an angle (like a 45º ramp) could it help to better homogenize the liquid aluminum? I ask this because I already got voids at the bottom and ends of some flat positioned castings. I also watched your video where you place a steel plate against the bottom and get good results, but I was using greensand.
Hunter, Foam and plaster? I hope that you do NOT mean plaster of Paris it contains lots of water and will cause problems. Thinned down dry wall compound (the non curing type) will work well though I believe. Check out the work of Kelly Coffield who is expert at one off lost foam castings. He would probably pour something like this at close to vertical. The use of a steel plate is to chill the metal and this makes it more gas and shrinkage free as well as giving it a finer stronger structure. It also promotes feeding by increasing the thermal gradient across the casting. I am not sure how you could combine chills with lost foam - never done it, never seen it done, doesn't meant that it can't be though.... Martin
Excellent information Martin [as allways!] A quick question please, I know you cast alloys but the principle is prob the same, I want to cast brass & bronze barstock [not at the same time!!hehe] some 3/8" 1/2" & 3/4" dia, for turning model steam engine fittings, ,in the past I just poke bars vertically into greensand but they often look great from the outside but on machining they have porous spots in the middle, Any ideas please? thanks Graham.
Graham, Ah yes, the old "lets cast own bar stock idea". After all "how hard can it be?" I am not trying to rubbish it, its just that most people do it so badly and end up with such defective castings that its all a bit of a dead loss. I note that those who claim it works for them seem to have low standards when it comes to casting quality 😊. The best way was invented by this bloke called Durville who solved the French mint's problem with aluminium bronze ingots for coin production - they had so much aluminium oxide film in them that they just split when rolled to coin thick sheet. See here for an introduction to his solution academy.ampcometal.com/a-brief-insight-into-the-history-of-tilt-casting. This is a bit complicated for the hobbyist but I do have some ideas to improve your chances, come to me at olfoundryman@gmail.com and I will explain. I will swear you to secrecy though, as I hope to do a video on the subject... Martin
Why would you cast brass and bronze? You can buy it ready made in the sizes you want. So much effort to cast it and for steam engine parts it should be good material.
@@smallcnclathes Why would I want to cast brass & bronze? the answer to that is, that's why I have a foundry, & I have a good supply of brass, bronze & alloys, & bronze bar is not that cheap, brass a bit cheaper.
Good day sir, I'm a machinist before but now i shift to make my diy casting. Now I'm making parts from the scrap aluminum, I've made it thicker but my problem is that, my product will crack. Well not all but sometimes it will crack, I know that there's gas trap inside the metal because when I'm going to machine, stinky smells comes out,.. now, I've researched and watch your videos, i need hydrogen to let the gas out, now, is this salt and chlorine will help to degas the aluminum and the salt helps to extract the impurities? I saw also they're using candle. If im going to combine salt, chlorine, and candle wax wrap to a foil, will this work? I hope you understand what i mean. Any explanation and help will be greatly appreciated. Thank you sir.
Boy, Lots of questions here! Before I get into them can you tell me what sort of scarp you are using - be as precise as possible? The fact that you sometimes get cracks and sometimes not suggests a problem of variable material . What sort of die coat are you using? The stinky smell is most likely acetylene it forma when carbides in the metal are exposed to air and the moisture that it contains, the carbides (likely aluminium carbide) react with the moisture to produce acetylene and hence the smell. I will get into the issues of fluxes etc. when you answer the questions..... Martin
@@olfoundryman8418 any kind of scrap aluminum, like brakeshoe, piston, motorcycle head cylinder, motorcycle hub mostly scrap aluminum from motorcycle, I melt it without cleaning, i soak any aluminum, scope the buff gently, since this is only diy, I don't have like yours to remove the gas, and i really need the most common types of chemical or whatever to remove the impurities, maybe you have any idea regarding on this, i used only charcoal burner and not graphite crucible, only from gas tank. I keep on searching on how to removed the flux,.. flouride is difficult to find from my place. I worked before in a very big smelter company but there using fluoride, metal fluxing like yours and then go to homoginizer. If candle can really help, or chorine, or salt i really dont know. I don't know also what type of alloy the motorcycle parts mostly using. Sorry for my english, I've tried only to explain, maybe you can help. I've tried to make triple tree clamp from motorcycle, and I've got a problem 2times already, it cracks maybe a week after installing, the crack was in the area where the bolt is tightened. Thickness 18mm, and with is around 9to10 mm.
@@boytaloy3756 There are so many potential problems here with what you are doing that it is difficult to know where to start. I would judge a triple tree as a critical component from a structural and safety point of view. I believe it requires the very best of metal and technique. Considering that I would never attempt to make one as the consequences of producing a bad casting are disastrous. The casting would need to be well designed and flawless and also fully T6 heat treated. Why it takes a week for the cracks to develop is a complete mystery to me. But I think that most of your problems come from the metal that you are using. I long ago found out that the only thing you can reliably make by melting down all sorts of scrap is more scrap - sometimes you will get a reasonable casting and sometimes not. If the product that you are making is not critical and has low strength and corrosion resistance requirements you can get away with it - sometimes. But you are trying to produce a safety and strength critical component. I believe that your chances of doing this reliably from melted down scrap are zero. To make it even worse you are mixing scrap that is obviously made up from several different alloys. What you will get with each melt is unknown - its casting properties will vary batch to batch as will its strength, response to heat treatment, corrosions resistance and ductility etc. It does not matter how much you degas or flux the sort of metal mix that you are using you will never turn it into reliable metal. (Big recyclers with the knowledge and equipment including full analytical facilities can do this but small users like us cannot.) You need to use good known metal. My suggestion would be the 356 alloy. You can get this from old alloy wheels but I do not advise doing so as not all wheels are made from 356 (BMW wheels for example are not) In your place I would sell all the scrap you have and use the money to but some 356 ingot - either for a reputable ingot supplier or possibly from a local foundry who may be prepared to sell you some ingot for cash. I don’t really see much of a problem in melting with charcoal except that temperature control may be difficult. You MUST though, melt in a proper crucible NEVER NEVER melt in a steel crucible. You should never overheat the metal - a maximum of 760 deg C is allowable. With good metal degassing and fluxing are sometimes not necessary. For my gravity diecasting work, I do not degas and I just use a little drossing off flux - just to clean the surface of the molten metal. Salt (sodium chloride) is useless as a flux because its melting point is too high and fluxes need to be liquid to work. A 50:50 mix of sodium chloride and potassium chloride - sold in grocery shops as “Lite Salt” is in theory better as it melts at a much lower temperature. However, such a mix will NOT dissolve aluminium oxide so it cannot clean the metal. You need to add a fluoride to this mix, say 5 to 15% of sodium fluoride or the commonly used cryolite - sometimes you can buy these from pottery supply companies. This flux will not degas the metal and if at all damp will actually increase gas levels. People plunge all sorts of crazy things into molten aluminium in the very mistaken belief that they will clean and / or degas the metal. Washing soda, baking soda, Epsom salts are common examples and ALL just add gas and oxide rather than remove it. I do not believe that candle wax will do any good either. I am sorry to be so negative but you are trying to produce a safety critical part out of scrap and such attempts will only lead to disaster and possibly loss of life. Even with good metal and good technique I would refuse to make this part as its just too critical. I suggest that you find something less critical to make. Regards, Martin
@@olfoundryman8418 I understand sir, and thank you for your advise, will maybe I will try to work abroad again and concentrate to my profession as a cad cam programmer or a cnc machinist or manual machinist. I will leave this business soon. Thank you and more power to your channel at best of luck to your hobbies or businesses. Thank you
Mario. No, wisely I have stayed away from magnesium. A fellow foundryman local to me did a fair bit of it and he used to say that reject rates were significantly higher than with aluminium. He never had a fire but did have the fluxes to help suppress fire. I used to nervously watch large holding pots of Mag at VW Australasia during my time there - it was common to see a small white flame lazily lick its way across the top of the metal fluxes help keep it small (hopefully!) occasionally a furnace would catch fire badly and the approach was to turn the furnace off and hurriedly build a wall of sand bags around the furnace. A front end loader would then bury the furnace in cast iron chips. A week or so later when all had cooled down the same front end loader would come back and pick up the whole furnace and dump it out back, a new furnace was then installed 😊. There are chemicals which will put burning Mag out sulphur hexaflouride SF6 now difficult to obtain and hideously expensive. It will burn in CO2 (a bit slower than in air) Argon may smother it. It will react with water - even the water in mouldings and and it will also react with the sand itself, inhibitors like KBF (I think) or amonium biflouride will stop this reaction. Sands containing these inhibitors can not be used for casting other metals. Dusting sulphur on the burning Mag will also help and dusting S on the stream of Mg during a pour is very common practice. My advice -stay away from it......Martin
@@olfoundryman8418 wow, definitely not for me. It amazes me how the Italians seem to be all over it, they make lots of components for the motorcycle racing industry. Then again they’ve been doing it for a thousand years
Mario, Well, they have not been casting magnesium for thousands of years! Its not much over a century old as an in use metal. But its like anything once you get to grips with and master the necessary foibles of the material that you are working with you get good at it. I suspect that it was the Germans who first became good with magnesium by the way.... Martin
So, Maybe I should put the electric whisk back in the kitchen cupboard before the wife notices, have you got any tips on getting metal residue off of stainless steel? All joking aside, It's nice to know that my intuition about stirring was along the right lines. While I don't stir in quite the same way that you do it, it's to much the same effect, with minimal disturbance of the surface.
When I was working in a Scottish foundry earlier this year, I saw and used a lot of homemade dross skimming tools- heavy low carbon steel, bent at an end. One for each metal, ferrous and copper based alloys. I especially liked the small shovel used solely for aluminum. Check my chanel for some 'professional' videos and be critical in commenting my errors :D
Your Dawn vice has 6HQ on it, how old or not old is it? And do you know for sure what the HQ stands for? I mean from the horse's mouth, not the high quality assumption :-) looks fantastic either way. PS I have a 55kg 6OS (offset) :-)
Fredio, Well, I guess I had assumed the unmentionable obvious 😊. However I know someone who knows the people who took over the Dawn group I will see if I can get him to find out - but be prepared for the worst as the horse is probably long dead. I was given this vice by a friend who decided that the little 3 inch I had made whilst studding Metallurgy at RMIT was too small. He appeared one day saying "I have a vice for you, get the wheelbarrow" Says me "I don't need a wheel barrow for a vice" "Just get the barrow" he said sternly so I did and yes I did need it. It is a quick action type (maybe that's what the HQ signifies) but to be honest it's a bit of a candidate for a YT restoration video - it has seen better days. I have never even bothered to bolt it down it is so heavy who needs bolts 😊 I am very glad of it.... Martin
I look forward to your reply once you find out. You have or had a great friend. I bet you're right about the letters meaning, perhaps Hold Quick or similar. Please don't restore it, the patina is beautiful. If you insist, allow me to give you a call and explain my philosophy on that process since so many vices are permanently disfigured and destroyed for TH-cam ad revenue.
fredio, Well, I am not into ad revenue - I am not monetarized. As far as I went with restoration was to make a set of aluminium jaws as the originals were missing. Do you live close - I am in Melbourne Australia... Martin
Just, Do you mean why was the video recommended to you or do you mean why is it recommended that your stir metal this way? If the first then I guess you would have to ask the YT algorithm - way beyond my pay grade! If the second then the answer is to improve the properties of cast metals.... Martin
Sellam, I add an exothermic product. It is called "Ferrux NF" and it is made by Foseco. Its job is to catch fire and thus generate a lot of heat that keeps the metal in the feeder liquid for longer so it is better able to feed the solidifying metal underneath.... Martin
Stirring up the TH-cam casting community again Martin? Are you sure that your middle name is not Luther? Now I am the one stirring you! ;-) Mark from Melbourne
On looking at the video I notice that I incorrectly broke the surface 😱 while stirring the "right' way. I can only put this lamentable error down to concentrating on what I was saying rather than what I was doing - sorry about that 🙄. I hope that you can do better..
I note that some paint manufacturers are advising stirring in this "right" way. Stands to reason I guess as you do not want air whipped into your paint and you do want the bottom bought to the top and stirred in.....Martin
You're forgiven!
Thank you for posting this video !
Don't worry, the concept is always clearly explained.
Greetings from Galicia Spain.
hello, what material of product did you mix with the sand so that it becomes wet, thank you.
Sellam, My sand is a natural green sand so it is made wet with water.... Martin
Nice to have you back. You are such a good resource.
pallepirat, Thank you.... Martin
Excellent video here. The main takeaway, of course, is to be as gentle as possible when working with molten metal.
Mister, Absolutely! Turbulence is the enemy. This does not mean that you need the impossible target of lamella flow just that you MUST avoid breaking and folding in of the surface.... Martin
Very good video, as always very informative. Glad to see you back at it Martin!
Wilkus, It's good to be back and I hope you found the video useful.... Martin
Martin I have found all of your videos helpful over the years, there are so many people on TH-cam doing it the wrong way, it amazes me how people "damage" their metal by using improper processes. There are so many ingot polishers on here and when I see those videos I scroll past. Thank you for putting up premium content.
I never thought about introducing air to my melted metal, thanks for the new video!
Brent, Without doubt introducing air into metal is responsible for a very large percentage of casting defects - and without doubt its the worst thing you can do. Molten metals are very reactive and will "burn" with any air to form oxides and sometimes nitrides to the great detriment of properties... Martin
It even makes sense to have a movement that goes up and down to mix the top and bottom metals together:: bring the bottom metal up, push the top metal down. Instead of string and expecting that the metals will be agitated enough to mix.
Olivier, Exactly!..... Martin
Thanks Martin. I'm ashamed to admit that I was something of a stirrer once but I'm changing my ways.
Mark, Most of us were but the important thing is "were" not "am"... Martin
Martin in his Element! Its like in the dancing school! Cross - up - over - down.....good to see you fresh and motivated!!
Best Regards from the other side of the planet!
Thomas, Yep, nothing like a bit of old time dancing foxtrot, barn dance, modern waltz, I did them all - Oh so long ago. In fact I met my wife at Doris Jacobs (she was something of a local legend) dancing classes - true story.... Martin
Great demonstration, thank you for sharing.
Heinrichs, My pleasure.... Martin
Great explanation, as always. Glad to see you back on TH-cam. Hope you are feeling better.
Earthy. Eh, not really feeling better just struggling on. Something like this, a few minutes at a time I can manage - sometimes. Just need to get those few minutes longer... Martin
We appreciate you sharing your experience Martin.
Rotary, My pleasure.... Martin
Thank you for making this video - I now know something that I never knew before and will be a better craftsman as a result.
Alpha, Excellent!.... Martin
Hard to argue when you make sense. If only all the amateur foundrymen and women would watch this. Nice to see you back at the educational videos Martin.
Mark
Mark, I too wish that all foundrymen both amateur and professional would watch (would do wonders for my views 😊) Many professionals are worse that a lot of hobbyists - I do not know why they are still in business. But I sure wish they would watch me rather than some of the misleading stuff out there. More vids to come Hope - a head full of ideas...Martin
Great video and explanation. I miss the old Pablo jars they were very handy 😁
Will, The wife was very loath to loan me one of those jars - she has a fair number and the were her mothers - irreplaceable now of course. She was terrified I would break it. Fortunately for my access to a warm bed I did not break it.... Martin
Martin, thank you for all the time you spend editing and piecing your videos together. I would like to ask a question which I hope is not really dumb. Is it feasible to place reinforcing steel in the mould and then pour the aluminum around it? The intention being to give it more strength.
Iafarms, Not dumb at all. I do something similar with casting aluminium around a heating element :- see here studio.th-cam.com/users/videoQ4sGl4jOQtA/edit Of course this is not for strength but it is cast in just as a steel reinforcement might be. Note that I preheat the element to make sure that the aluminium runs around it properly. I doubt that you will get any true bonding with the steel reinforcing and I am not sure how much strength increase you will get or how reliable casting to casting it might be. You might just be better producing a superior quality casting out of, say, 357 alloy and then having it properly T6 heat treated.... Martin
@@olfoundryman8418 Thank you Martin, I would only be making two, or three and stretch the third unit it fails. I had not thought about casting around a heating element. That solves another project! David
Thank you Martin.
@turbo, My pleasure.... Martin
Hi Martin, I think I'd seen you possibilities video before my second attempt @ a pour so didn't stir and when I took the dross out was a lot more gentle! Thanks for all your videos and help, stay safe n well. TFS, GB :)
Graeme, One should treat ones metal like a beer pour gently and don't stir.... Martin
Hello Martin,
Excellent video, well explained and demonstrated. Thank you.
Take care.
Paul,,
Paul, Glad that you liked it.... Martin
So good to see you back Martin! Hope you are all well.
John, Not well but battling on - sort of 😊. Thanks for asking.... Martin
Awesome! thanks I'm glad I could learn something from an old master of a trade.
ihdieselman, If I have managed to pass on some useful information to you then I am well pleased.... Martin
Thank you Martin glade to see your well stay safe cheers
Colin, Thank you for your good thoughts, not as well as i would like to be but battling on.... Martin
I had a buddy who for some perverse reason had a passion for old Skodas - I think mainly because he got them for free. We were moving an engine-transmission and we let it drop onto the ground from the tremendous height of an inch. The transmission broke cleanly into two neat pieces. The interior of the casting had uniformly the appearance of a metal aerobar. Interestingly the casting exterior finish was superb - still wondering if this was intentional, sabotage or an unhappy accident. Love the channel.
francis, I understand perverse passions for odd vehicles only too well - I have been thus afflicted most of my life. Your metal aerobar casting sounds like a pressure diecasting. These commonly have a good surface finish. But the process relies on squirting metal into a die at just about sonic velocity much air can be entrained during this process and if the die is not well designed (many are not) you get the trapped air bubbles that pressure die castings are often known for. So intentional - no, sabotage - no, unhappy and likely recurring accident - yes.
I love that you love the channel.... Martin
Thanks again - really great and usable information. I love how you share the evolution of your technique with the clangers along the way. Pressure diecasting makes sense - never having seen it in action I respect your analysis. I appreciate perverse passions - I wouldn't mind a Bristol or a panhard or a Vincent - a Skoda is more a lingering STD one can do without!@@olfoundryman8418
Wise words Martin.
B Clare Thank you... Martin
Thank you so much for sharing this very useful information!
user, My pleasure.... Martin
Thanks for sharing your knowledge. It has been very helpful
Mark, Sharing is my pleasure... Martin
Awesome advice. Keep educating, your help is much appreciated.
Krashan, My pleasure... Martin
Greatly and clearly explained.
Maybe black dye wasn't the best color choice.
Gafrers, Maybe not 😊! To be honest the dies dispersed into the water way to quickly - I guess they are made to do that. But I really needed something that would mix in with a little more difficulty as I had hoped to show better mixing with the "right way" as well as the more important no air introduction. Perhaps a small amount of a thick water based house paint may have been better?.... Martin
And whipping away at like it's a cup of tea also results in the vortex paradox, where the heavier material gets concentrated in the centre of the vessel at the bottom.
So it's just a BAD technique all around to stir the metal like it's a cup of tea or coffee.
Lancer, Yep, but I guess its possible to stir tea (or coffee) with this down across up across down motion too 😊 but furiously round and round with the spoon, no, definitely not.... Martin
Good morning .
my compliments for her foundry culture both theoretical and practical. I would like to know, if possible, how your molding sand mixture is composed. Given the excellent results of the castings she produces.
Sincerely
Alfio Antonini
alfio, The sand I use is a natural green sand. IT came from a quarry about 30 Km from where I live. As such it is composed of fine sand with about 15 to 20 % of a natural clay plus water.... Martin
Going to make better foundry men out of us all.
D, That's the aim 😊.... Martin
I learn watching each of your videos, many thanks
Gr eg, Thank you for saying so.... Martin
Very nice; thanks for that. I guess it's good to try to build a better sense of what's happening to the metal at each step along the way; a feel for it. It's too easy to just take a quick intuitive approach without thinking about what's really happening!
Phreadrick, I could not have put it better than you have here. Well said... Martin
Never thought about it, but makes perfect sense. Thanks.
Wanta, I think that you have hit the nail on the head. People do not think about these things but they are important.... Martin
G-day mate, catching up on a few videos at last, I will drop you a line. keep up the sweet little how to videos, think it's going to help a lot of people out.
Andy, Finally given up revving the crap out of that poor little Mazda? Front wheel drive is so damn useless up slippery hills particularly if you over do the revs😊 How many sets of front tyres did you wear out? All that smoke!!! 😱.... Martin
Ahh The MX5 is rear wheel drive Martin. No not given up, Mike has had a back op, so is out of action, I could have taken the MX on an event with someone else, but I have done that once already & as we co own the car, I felt I'd rather wait until he's fit again.
last event we got through 2 tyre's, never due to wear, it's always punchers on the rock :(
I do a punge motion. But taal under the surface of the metal. Basically the same just in the opposite direction
Manus, Anything that brings top to bottom and bottom to top without breaking the surface is good.... Martin
Great video , I noticed you have a Mill in the background in your video , it looks like an Archdale vertical mill with a sliding head, I am asking as I have an Archdale VM30 , getting information on has proven fruitless as I am yet to get anything of use like an exploded diagram showing how it's put together , even a scanned copy of an owners manual would be of use
Allan, Thanks for your comment. I assume that you mean the mill right at the back that pretty much only the head of is visible, sorry but its a Cincinnati #2 vertical (I call her the "beast" - she weighs close to 3 t) so I can not help you with any info on your Archdale -sorry.... Martin
@@olfoundryman8418 Yes that machine you describe looked similar to my Archdale , it would be around the same weight as well, I just did a search on the model and while it has a sliding head like mine it is noticeably different to mine , I do know from others that it was made in the 1920s . I couldn't see enough to be sure of much , hanks for coming back to me
Im a machinist in the states and I have done some home aluminum casting in the past but I wasnt good at judging sprue, runner and riser sizes. I am getting ready to pour a prototype cylinder head for a pulling tractor. The one I am casting is just the size for 1 cyl. The casting will basically be a block of aluminum 6 1/2" x 7 5/8" x 5" thick with 2 cores for the intake and exhaust port. Would you have an idea of the size of the sprue , runner and the risers needed.
James, Hang on - a case of more information needed 😊. You seem to be talking about a rectangular lump of aluminium that neglecting the two port cores will weigh in at about 24 lb by the time we add about 16 Lb for feeders gates runners etc - that is a 40Lb casting. That seems very heavy for a single cylinder head.😱 So do you have a photo or drawing or even a sketch of the actual shape that you are after? You can send it to olfoundryman@gmail.com
Martin
in traditional bell casting they use a spruce stick to stir the bronze. what's your opinion on that?
Bbuse, I believe that the spruce stick is to remove oxygen from the metal by virtue of the hydrocarbon gasses it gives off and not so much to stir it. It is a somewhat older technique and better methods are available today. To be honest I don't think too much of the method as water vapour is also given off and this can cause all sorts of problems with the metal, not to mention safety issues, pays to stand well back! Remember they start with ingots of the required alloy so no actual stirring is necessary.... Martin
Good information. Thanks
Ron, Hope that you find it useful... Martin
Thanks for sharing 👍 it's good information.
Craig, Nice to hear from you again - I hope that you find the information of use.... Martin
Hello Martin, I'm into metal casting since two months now. I've build my own furnace and started my firts attempts to cast some simple parts from aluminium. After inplementing some of your tips - the results are getting better. Entraining of air was the biggest issue at the beginning. Since I got rid of the 'ridicoulously big pouring funnel' as you called it and reducing the diameter of the infill drastically - I was very pleased to see the first part without any visible inclusions. Thank you, very much for sharing your knowledge. I assume that the correct pouring temperature is also very important. I guess I always overheating the metal. Could you please be so kind to explain what kind of equipment you use to measure the temperature? Do you use a thermocouple? Which brand and how you protect it from the high heat?
el, Yes, there is a right way and a wrong way as with most things. The right way gives a much better chance of a good casting. Temperature is important. A max of 760 deg C is advisable for aluminium as temps above this can cause bad gas problems. I tend to pour a bit hotter than perhaps I should - most of my castings are poured at 720 to 745 deg C. I have covered the thermocouple question in another answer to you but please note that the protective wash I mentioned i.e. the BN hardcoat is only of use up to 900 eg C so it is useless for bronze..... Martin
Thank you. I've found a dipstick sensor with a copper plating which should withstand temps up to 1100°C. I'm not sure if the hot aluminium will stick to the sensor or how fast it will be corroded. www.thermagmbh.de/en/shop/product/thermocouples/dipstick-thermocouples/dipstick-thermocouple-teflon-type-k/
@@elpresidente4441 This might be better and cheaper too plus it has the instrument that gives the readout www.ebay.com.au/itm/282576231648?hash=item41cadb1ce0:g:2e0AAOSwW4hcdcDy It is also thicker so a bit more robust (maybe ) coat the end that will go into the metal with some sort of a ceramic wash like a thin layer of fireclay and sodium silicate mixture painted on and dried. Get the longest one.... Martin
Hello, I want to cast an aluminum plate (12mm thick), so I need two sides to be as parallel/flat as possible so I don't have to face it too much later (my weak cnc router would appreciate it). I will use foam and plaster for this process. My question is: Should I position the mold flat to the flask as usual, or positioning it at an angle (like a 45º ramp) could it help to better homogenize the liquid aluminum? I ask this because I already got voids at the bottom and ends of some flat positioned castings. I also watched your video where you place a steel plate against the bottom and get good results, but I was using greensand.
Hunter, Foam and plaster? I hope that you do NOT mean plaster of Paris it contains lots of water and will cause problems. Thinned down dry wall compound (the non curing type) will work well though I believe. Check out the work of Kelly Coffield who is expert at one off lost foam castings. He would probably pour something like this at close to vertical. The use of a steel plate is to chill the metal and this makes it more gas and shrinkage free as well as giving it a finer stronger structure. It also promotes feeding by increasing the thermal gradient across the casting. I am not sure how you could combine chills with lost foam - never done it, never seen it done, doesn't meant that it can't be though.... Martin
"Cocktail mixology " 👍
Jamie, You betcha.... Martin
a very informative and sensible vid, thanks
hrxy, I am glad that you found it so, and thanks for saying so.... Martin
Thank you!
Freeman, My pleasure.... Martin
Excellent information Martin [as allways!] A quick question please, I know you cast alloys but the principle is prob the same, I want to cast brass & bronze barstock [not at the same time!!hehe] some 3/8" 1/2" & 3/4" dia, for turning model steam engine fittings, ,in the past I just poke bars vertically into greensand but they often look great from the outside but on machining they have porous spots in the middle, Any ideas please? thanks
Graham.
Graham, Ah yes, the old "lets cast own bar stock idea". After all "how hard can it be?" I am not trying to rubbish it, its just that most people do it so badly and end up with such defective castings that its all a bit of a dead loss. I note that those who claim it works for them seem to have low standards when it comes to casting quality 😊. The best way was invented by this bloke called Durville who solved the French mint's problem with aluminium bronze ingots for coin production - they had so much aluminium oxide film in them that they just split when rolled to coin thick sheet. See here for an introduction to his solution academy.ampcometal.com/a-brief-insight-into-the-history-of-tilt-casting. This is a bit complicated for the hobbyist but I do have some ideas to improve your chances, come to me at olfoundryman@gmail.com and I will explain. I will swear you to secrecy though, as I hope to do a video on the subject... Martin
Why would you cast brass and bronze? You can buy it ready made in the sizes you want. So much effort to cast it and for steam engine parts it should be good material.
@@smallcnclathes Why would I want to cast brass & bronze? the answer to that is, that's why I have a foundry, & I have a good supply of brass, bronze & alloys, & bronze bar is not that cheap, brass a bit cheaper.
@@olfoundryman8418 Thanks for the reply Martin ,very good of you ,I'll be in touch.
Graham.
Very Clear. Thanks
Rex, Thanks for saying so.... Martin
Good day sir, I'm a machinist before but now i shift to make my diy casting. Now I'm making parts from the scrap aluminum, I've made it thicker but my problem is that, my product will crack. Well not all but sometimes it will crack, I know that there's gas trap inside the metal because when I'm going to machine, stinky smells comes out,.. now, I've researched and watch your videos, i need hydrogen to let the gas out, now, is this salt and chlorine will help to degas the aluminum and the salt helps to extract the impurities? I saw also they're using candle. If im going to combine salt, chlorine, and candle wax wrap to a foil, will this work? I hope you understand what i mean. Any explanation and help will be greatly appreciated. Thank you sir.
Boy, Lots of questions here! Before I get into them can you tell me what sort of scarp you are using - be as precise as possible? The fact that you sometimes get cracks and sometimes not suggests a problem of variable material . What sort of die coat are you using? The stinky smell is most likely acetylene it forma when carbides in the metal are exposed to air and the moisture that it contains, the carbides (likely aluminium carbide) react with the moisture to produce acetylene and hence the smell. I will get into the issues of fluxes etc. when you answer the questions..... Martin
@@olfoundryman8418 any kind of scrap aluminum, like brakeshoe, piston, motorcycle head cylinder, motorcycle hub mostly scrap aluminum from motorcycle, I melt it without cleaning, i soak any aluminum, scope the buff gently, since this is only diy, I don't have like yours to remove the gas, and i really need the most common types of chemical or whatever to remove the impurities, maybe you have any idea regarding on this, i used only charcoal burner and not graphite crucible, only from gas tank. I keep on searching on how to removed the flux,.. flouride is difficult to find from my place. I worked before in a very big smelter company but there using fluoride, metal fluxing like yours and then go to homoginizer. If candle can really help, or chorine, or salt i really dont know. I don't know also what type of alloy the motorcycle parts mostly using. Sorry for my english, I've tried only to explain, maybe you can help. I've tried to make triple tree clamp from motorcycle, and I've got a problem 2times already, it cracks maybe a week after installing, the crack was in the area where the bolt is tightened. Thickness 18mm, and with is around 9to10 mm.
@@boytaloy3756
There are so many potential problems here with what you are doing that it is difficult to know where to start. I would judge a triple tree as a critical component from a structural and safety point of view. I believe it requires the very best of metal and technique. Considering that I would never attempt to make one as the consequences of producing a bad casting are disastrous. The casting would need to be well designed and flawless and also fully T6 heat treated.
Why it takes a week for the cracks to develop is a complete mystery to me.
But I think that most of your problems come from the metal that you are using. I long ago found out that the only thing you can reliably make by melting down all sorts of scrap is more scrap - sometimes you will get a reasonable casting and sometimes not. If the product that you are making is not critical and has low strength and corrosion resistance requirements you can get away with it - sometimes. But you are trying to produce a safety and strength critical component. I believe that your chances of doing this reliably from melted down scrap are zero.
To make it even worse you are mixing scrap that is obviously made up from several different alloys. What you will get with each melt is unknown - its casting properties will vary batch to batch as will its strength, response to heat treatment, corrosions resistance and ductility etc. It does not matter how much you degas or flux the sort of metal mix that you are using you will never turn it into reliable metal. (Big recyclers with the knowledge and equipment including full analytical facilities can do this but small users like us cannot.)
You need to use good known metal. My suggestion would be the 356 alloy. You can get this from old alloy wheels but I do not advise doing so as not all wheels are made from 356 (BMW wheels for example are not) In your place I would sell all the scrap you have and use the money to but some 356 ingot - either for a reputable ingot supplier or possibly from a local foundry who may be prepared to sell you some ingot for cash.
I don’t really see much of a problem in melting with charcoal except that temperature control may be difficult. You MUST though, melt in a proper crucible NEVER NEVER melt in a steel crucible. You should never overheat the metal - a maximum of 760 deg C is allowable.
With good metal degassing and fluxing are sometimes not necessary. For my gravity diecasting work, I do not degas and I just use a little drossing off flux - just to clean the surface of the molten metal.
Salt (sodium chloride) is useless as a flux because its melting point is too high and fluxes need to be liquid to work. A 50:50 mix of sodium chloride and potassium chloride - sold in grocery shops as “Lite Salt” is in theory better as it melts at a much lower temperature. However, such a mix will NOT dissolve aluminium oxide so it cannot clean the metal. You need to add a fluoride to this mix, say 5 to 15% of sodium fluoride or the commonly used cryolite - sometimes you can buy these from pottery supply companies. This flux will not degas the metal and if at all damp will actually increase gas levels. People plunge all sorts of crazy things into molten aluminium in the very mistaken belief that they will clean and / or degas the metal. Washing soda, baking soda, Epsom salts are common examples and ALL just add gas and oxide rather than remove it. I do not believe that candle wax will do any good either.
I am sorry to be so negative but you are trying to produce a safety critical part out of scrap and such attempts will only lead to disaster and possibly loss of life. Even with good metal and good technique I would refuse to make this part as its just too critical. I suggest that you find something less critical to make.
Regards, Martin
@@olfoundryman8418 I understand sir, and thank you for your advise, will maybe I will try to work abroad again and concentrate to my profession as a cad cam programmer or a cnc machinist or manual machinist. I will leave this business soon. Thank you and more power to your channel at best of luck to your hobbies or businesses. Thank you
Hey mate, just wondering if you’ve ever done any magnesium casting, I’d imagine it’s a lot more difficult than aluminium and dangerous?
Mario. No, wisely I have stayed away from magnesium. A fellow foundryman local to me did a fair bit of it and he used to say that reject rates were significantly higher than with aluminium. He never had a fire but did have the fluxes to help suppress fire. I used to nervously watch large holding pots of Mag at VW Australasia during my time there - it was common to see a small white flame lazily lick its way across the top of the metal fluxes help keep it small (hopefully!) occasionally a furnace would catch fire badly and the approach was to turn the furnace off and hurriedly build a wall of sand bags around the furnace. A front end loader would then bury the furnace in cast iron chips. A week or so later when all had cooled down the same front end loader would come back and pick up the whole furnace and dump it out back, a new furnace was then installed 😊. There are chemicals which will put burning Mag out sulphur hexaflouride SF6 now difficult to obtain and hideously expensive. It will burn in CO2 (a bit slower than in air) Argon may smother it. It will react with water - even the water in mouldings and and it will also react with the sand itself, inhibitors like KBF (I think) or amonium biflouride will stop this reaction. Sands containing these inhibitors can not be used for casting other metals. Dusting sulphur on the burning Mag will also help and dusting S on the stream of Mg during a pour is very common practice. My advice -stay away from it......Martin
@@olfoundryman8418 wow, definitely not for me. It amazes me how the Italians seem to be all over it, they make lots of components for the motorcycle racing industry. Then again they’ve been doing it for a thousand years
Mario, Well, they have not been casting magnesium for thousands of years! Its not much over a century old as an in use metal. But its like anything once you get to grips with and master the necessary foibles of the material that you are working with you get good at it. I suspect that it was the Germans who first became good with magnesium by the way.... Martin
So we shake the crucible, not stir -ok got it mr. PetroBond !
"Shaken, not stirred." 🤣
Zum, dfross, Indeed 😊.... Martin
So, Maybe I should put the electric whisk back in the kitchen cupboard before the wife notices, have you got any tips on getting metal residue off of stainless steel?
All joking aside, It's nice to know that my intuition about stirring was along the right lines. While I don't stir in quite the same way that you do it, it's to much the same effect, with minimal disturbance of the surface.
Leon, Anyway that does not break the surface and does not drag in air is a good way.... Martin
When I was working in a Scottish foundry earlier this year, I saw and used a lot of homemade dross skimming tools- heavy low carbon steel, bent at an end. One for each metal, ferrous and copper based alloys. I especially liked the small shovel used solely for aluminum.
Check my chanel for some 'professional' videos and be critical in commenting my errors :D
Your Dawn vice has 6HQ on it, how old or not old is it? And do you know for sure what the HQ stands for? I mean from the horse's mouth, not the high quality assumption :-) looks fantastic either way. PS I have a 55kg 6OS (offset) :-)
Fredio, Well, I guess I had assumed the unmentionable obvious 😊. However I know someone who knows the people who took over the Dawn group I will see if I can get him to find out - but be prepared for the worst as the horse is probably long dead. I was given this vice by a friend who decided that the little 3 inch I had made whilst studding Metallurgy at RMIT was too small. He appeared one day saying "I have a vice for you, get the wheelbarrow" Says me "I don't need a wheel barrow for a vice" "Just get the barrow" he said sternly so I did and yes I did need it. It is a quick action type (maybe that's what the HQ signifies) but to be honest it's a bit of a candidate for a YT restoration video - it has seen better days. I have never even bothered to bolt it down it is so heavy who needs bolts 😊 I am very glad of it.... Martin
I look forward to your reply once you find out. You have or had a great friend. I bet you're right about the letters meaning, perhaps Hold Quick or similar. Please don't restore it, the patina is beautiful. If you insist, allow me to give you a call and explain my philosophy on that process since so many vices are permanently disfigured and destroyed for TH-cam ad revenue.
fredio, Well, I am not into ad revenue - I am not monetarized. As far as I went with restoration was to make a set of aluminium jaws as the originals were missing. Do you live close - I am in Melbourne Australia... Martin
Pretty close, let's say a short swim for a good keen man. I could call you for free though, if you'd allow me the honour. :-)
fredio, Don't get wet - Email me at olfoundryman@gmail.com and I will give you a phone number.... Martin
Why is this recommended
Just, Do you mean why was the video recommended to you or do you mean why is it recommended that your stir metal this way? If the first then I guess you would have to ask the YT algorithm - way beyond my pay grade! If the second then the answer is to improve the properties of cast metals.... Martin
comment s'appelle le produit que tu as ajouter dans cette video dans la minute 16:40 :th-cam.com/video/eWuytfsLl2o/w-d-xo.html&ab_channel=Olfoundryman
Sellam, I add an exothermic product. It is called "Ferrux NF" and it is made by Foseco. Its job is to catch fire and thus generate a lot of heat that keeps the metal in the feeder liquid for longer so it is better able to feed the solidifying metal underneath.... Martin
thank you very much
I was writing a comment about the black die until I seen the jars of pee then I realized I preferred the black..... LoL
XPNDBL, Black Pee - OMG 😱 go see your doctor😊... Martin
Stirring up the TH-cam casting community again Martin? Are you sure that your middle name is not Luther? Now I am the one stirring you! ;-)
Mark from Melbourne
Mark, I do have something of a reputation as a S**T stirrer. Ah well, you have got to have a hobby .😊... Martin