Some of the old timers used to put a thick layer of charcoal in the crucible on top of the metal working on the theory that as it burns it creates a layer of CO2 on top of the liquid metal to keep the oxygen away and prevent oxidation. The man who told me has been dead for decades now so I can't ask him what metals he used it with or how thick a layer but it might be worth experimenting with.
Makes sense. Another way is to put argon into the furnace or to bubble it up through the metal inside the crucible. This requires a tube that resists very high temperatures.
this is easily one of the most interesting casting vids ive seen. NO ONE addresses the difference in pure vs not, and what its missing, or how to adjust it. great vid man!
+explosev gamr the heat sink was just a thick chunk of aluminum to form a molten pool first. Cans are too thin and when they melt they oxidize, plunging them into an existing pool first helps prevent that.
Note on aluminum can alloy Typically it's 3003 From Wikipedia The alloy composition of 3003 aluminium is: Aluminium: 96.8 to 99% Copper: 0.05 to 0.20% Iron: 0.7% max Manganese: 1.0 to 1.5% Silicon: 0.6% max Zinc: 0.1% max Residuals: 0.15% max
As someone who hasn't progressed vry far from this finding out salt works like flux is huge. Borax in my area is expensive so I've been looking for an alternative thank you vry much for your videos they are extremely helpful@PaulsGarage
You should really rethink pouring over concrete. If the aluminum spills, the heat can cause the surface to literally explode into your face. Pour over sand or dirt.
Only two and a half years late to your vids, but better late than never! I'm going to try the Lo-Salt tip tomorrow because you're right - the amount of dross from cans is horrendous. In fact today I ended up with a smaller alumuffin (oooh, I like that!) than the one I STARTED with, despite adding a bucketload of cans: the amount of dross (and aluminium bound up in it) was greater in volume (if not weight) than the alumuffin. Love your channel - have a sub! :)
Im glad to have seen this video, thank you for posting it. I have just started forging and using the salt on my last 4 videos i was able to reclaim ALOT of alum from my dross. Also included my first attempts of sand casting... learning alot
This was fun, like the muffin pan mold,😊 forgot the Pam😊 hair dryer❤ Love your Proper English, you must be related to me we have our own family dictionary 😅 good job
Another good video Paul. If you find out what the can alloy actually is and what the silicon content of 356 aluminum is you can crush up the right amount of silicon and toss it in to improve the casting properties of the can metal. You can do the same thing by adding some aluminum from pistons because they're very high in silicon. Burning teflon is super poisonous.
Hi pete! I probably could crush up the silicon and add it to the aluminum, but i have lots of cast aluminum already and i don't want to waste the silicon. I might be able to get a hold of some junk pistons, though. Making everdur is something i want to do as soon as i get the next furnace built, though.
Thanks Paul! This a great tip! I have been collecting aluminum cans for awhile waiting for spring to start casting but was having doubts about using them because I kept hearing the same: they are a good cheap source of alumimum/they are garbage, don't use them. Relieved to know I can use them for casting projects. BTW, I enjoy many of your videos and the information you share. Thanks!
Hi stephen! this is a pretty old video, i would suggest using the aluminum from cans for making alloys like aluminum bronze, but I wouldn't use them alone for castings unless you have a mold with plenty of head pressure or something. This stuff will have a higher shrinkage rate and higher surface tension. Nothing that can't be compensated for, of course, but it's not ideal. I used these to make aluminum bronze (90% copper, 10% aluminum). It's great.
the lines you talked about comes from gasses in your mix, i've seen people use baking soda to combat that with reasonable outcomes. and the shrikage in the center of your ingots comes from having no silica (and also i think in part from the gasses)
Is it silicon carbide that's in cast aluminum? You can see it in the grain structure when you observe a broken piece. Shiny little specks. The shrinkage is natural and occurs in all molten metals to differing degrees as they cool.
Paul you can make a really good cheap propane burner just look up "how to make an aluminum foundry" by the backyard scientist. mine got hot enough to melt copper easily and you wont have to deal with refilling the charcoal every few minutes and you wont have a bunch of ash to deal with when your done melting to. fair warning make sure you have a thick and durable crucible because i have all ready burned holes in some of mine. good luck.
Thanks for the tip. I'm goign to make a propane burner before too long. With hardwood lump charcoal i never get ashes in the bottom of the furnace, but it burns out so quickly i can't get the thing reliably hot enough for copper.
Look out for cans with ANY moisture in them, cause if you put a can with moisture in a pool of molten aluminum you'll get a REALLY interesting explosion!!!
Awesome Video Paul - Thanks. Really liked 1) The Flux Experimentation - was cool that you fluxed the dross & squeezed out a bit more Aluminum and 2) Very interesting how to gain a better quality of Aluminum by adding %5 copper. For a while I was scrapping & collecting copper. A lot of the newer electronics save on the cost by using a super thin Copper coating on Aluminum wire for electrical conductivity. So I have quite a bit of Copper coated Aluminum wire that I thought was basically crappy Aluminum. However Thanx to your video the Copper coated Aluminum wire might just melt into a slightly better quality Aluminum!!! The one thing I wandered about was the dross in the crucible - if you had thick gloves or a better pair of tongs I wandered if you turned the crucible upside down & tapped it on the cement if the dross would fall out??? Thanx Again: Shawn
Thanks! THe fluxing worked really well, i was surprised. Someone recently told me that 95% aluminum with 5% copper is called duralumin if you want to look that up. It's a pretty decent alloy. I didn't record it, but i did actually turn the crucible over and bang it on the cement to get some dross out. Not all of it came out, though. Quite a bit stayed stuck in there. I don't have a way to scrape it out, but melting cans left FAR more crud in there than melting scrap cast aluminum, so i probably won't do cans again. All the dross was a good thing later, when i did the keychain casting video the crucible actually got a hole in the bottom of it and the dross and crud plugged it up so it was a very slow drip. I was able to pour and everything without losing any significant metal out the hole. It's in the garbage now, though.
Duralumin: 3,5-5,5 % Cooper; 0,5-0,8 % Magnesium; 0,6 % Manganese,94-95%Aluminium,Si=0.2-0,5%. (Cans are actually made from two alloys 5004 which is 1% each of Manganese and Magnesium used for the body of the can and 5182 1% Manganese and 4% Magnesium for the lid.(data from Olfounryman channel)) As you can see, your recipe with Cooper is so close...
Fighting recipe with dissolved metal crucible:mix ''liquid glass'' with refractory clay, or kaolin, or bentonite (cat litter), or chalk and paint every time before melting.Paint everything what you immerse in molten aluminium. Works very well!And cheap...
Toto hey I'm trying to understand what you're saying but I'm not sure I do . Could you explain what you said a little better ? Because I'm really interested in what your saying. Thanks !
Hey Paul, I just found your channel and your metallurgy tips are quite helpful. Now I will look around and hopefully find how you built your furnace. Thanks, Kenn
Finally the answer I was seeking. Off to remelt that shiny dross with some salt. I plan to use an ugly ingot to establish my pool for can melting. Look into fireplace gear for stirrers and grabbers. My "store" bought furnace kit came with some but not nearly as durable as my old fireplace tongs.
Cut up cans, ring-pulls, tops & bottoms of cans, & the shards covered In paint dross wise, this I just got to try, aluminium seems to be the easier to start off, so looking for electric smelter 3-4 kilos yes I have plenty of beer cans, all cut up & ready for smelting any advice you could possibly offer would be gratefully appreciated, many thanks, yours truly! P/S, thanks for the flux Info.
How did you crush your cans? When I crush mine, they end up to wide to fit inside any reasonable pool of aluminum, as they stand up instead of lay flat.
+capfer77018 I have one of those things that just bolts to the wall with a lever on it for crushing cans. I think the uncrushed ones were better to melt though.
These ones from the cans i plan to use for making alloys (like aluminum bronze), but that cast aluminum (aluminum with silicon in it) ingot i showed at the end i'm going to use for sand casting various things, including some tools from the Gingery book series i mentioned in some other video.
+ajinthevalley NS probably yes. The burner would work fine and it can get the metal to orange hot, but you would need better insulation if you want welding temperatures. Also the design is meant mainly to hold a crucible so the shape might not work for holding certain work pieces.
Oh, that would explain why the can tabs are more sought after than the actual can is, because those are apparently more pure aluminum?? Cool video, thanks man!
Yup I’m definitely happy I kept a goodly amount of old 400mh lamp ballasts Tonnes of aluminum and a tonne of copper Sad I sold the first batch of copper rather than melting it to pure but atleast I kept all the aluminum shades and ballasts 😊
In this video i used a steel crucible, but i would actually recommend not using steel. The thing died after the very next use (the keychain video) and now i have to replace it. I would suggest a graphite clay crucible for melting anything.
When you mix materials is important to consider if you are supposed to be mixing by weight or by volume. For example the same volume of copper might weigh 3 times as much, as you've shown. So when you say add 5% copper, you need to specify that you mean by weight, and not by volume.
@beefan1596 silicon is difficult to get and is unlikely to dissolve quickly in the melt. It would have to dissolve, not melt, because it gas a very high melting point. You CAN add a hypereutectic (oversaturated solution) aluminum-silicon alloy to it in the form of cast aluminum pistons, but getting the mix right is a bit tedius, and then you will still have some contamination. Definitely doable, but at that point just buying a345 ingots becomes much easier. These days I buy basically all the metal I use, but when i made this video I did more scrapping. Buying good metal instantly improved my castings
@@PaulsGarage Would turning it into a fine powder help, by any chance? Just asking out of curiosity - I'm not planning too hard on doing it myself; I have a decent supply of scrap aluminum already (although most of it is an alloy meant for machining rather than casting).
I have a bunch of small ingots from melting cans. Can I just use one of those to start the precursor pool, or does it have to be a higher quality aluminum?
Hey Paul - Paul here... good tip with the copper addition to the aluminum. I'm casting sculptures, and was wondering how to do away with shrinkage... mostly notice it in the Sprue, not the cast pieces below. I'd hate to find out the hard way. Subbed.
+zillustration hi Paul! Adding copper won't really help shrinkage as much as silicon, and aluminum will always shrink somewhat. If your sprues and risers are of sufficient size/locations, you shouldn't have damage to the piece. Are you doing lost wax or something?
search zillustration or paul zdepski on FB - i have some public on my page... plus pics of my furnace. Will be trying lost wax, but currently using Super Sculpey to make my models, then casting in fine green sand. A friend of mine is a jeweler, so he's got the super fine stuff. Great detail with finer sand.
+Cheerfultrout yes, in fact copper oxidizes more aggressively I believe. People often use cover fluxes or stuff charcoal in the crucible to take up the oxygen when doing copper.
Have you tried adding a bit of charcoal or coal to the crucible in order to consume the oxygen and prevent oxidation, or do you think it would just add to the impurities?
love the new video i wonder if you chemically treated the cans before to remove the paint and plastic if you'd end up with a lot less dross the pans i use are extruded and im 90% certain pure aluminum and i generally get very little dross. i think surface area has alot less to do with it and its mainly the vinyl paint, and plastic coating that is responsible for the dross.
Thanks! I think you are right, the plastic is the main problem. i'm sure there is a way to remove the coating with something, but i think just using extrusions is probably easier. there is so little metal in a single can that i doubt it's worth the effort.
no, if you remove the coating, you expose more aluminum to the air before hand, which will cause even more oxidization before you even get to start melting it. Most of the dross is from the side walls of the cans due to such thin aluminum. Try throwing aluminum foil in a fire, its like that. If you wanted maximum metal out of cans, you would just cut the tops and bottoms off of the cans and use only those, the side walls dont really have any metal to them.
thats a good point, the sides of the cans are stretched pretty thin, and the plastic would form a nice barrier. I bet as the plastic burns it would eat up some of the oxygen in the can, too, preventing the aluminum from oxidizing. the top is a different alloy, too, if i'm not mistaken, but it's just a couple percent manganese or something like that.
No- that is a thin, polished iron oxide on aluminum platters that you're thinking of. There is very little silicon in hard drives (only minute quantities inside the solid state devices (chips, transistors, diodes, etc)
when you ram up the furnace lid prop the steel band up 1/2 inch above the bottom face of the refractory. this will keep the steel hoop cooler and it won't expand so much.
the lid would help it melt aluminum faster, but it will still melt. there is a guy named makerj101 who used an open fire for aluminum casting, so hot lump charcoal isnt even required.
So you can fish the crap off of the top before you pour it, I've been doing that and it's made pouring much easier. I just smashed some scrap steel to make a spork type thing with a long handle to fish it off. Plus it's fun to play blacksmith and hammer stuff. I've never done the lite salt, but that is pretty great. I'll have to do that with my next batch.
The scooper is a good idea. I need to make one of those up. The spoon with channel locks just isn't capable of getting the dross out with the cans, there was just way too much of it. The dross left over is non-metallic though so that's nice, i think i got all the aluminum out with the lite salt.
garbage can. and this video is super old, i wouldn't recommend melting cans at all anymore. too much oxide waste, too much dross from the plastic can liner, and it's not the right alloy for casting
yeah cans are made from 2 alloys, neither of them flow well for metal casting. A356 is a good flowing aluminum alloy but it can't be formed into cans. You find that stuff as car wheels and some engine parts.
@davidwillard7334 still in a pile on the shelf, unfortunately. Most of them anyway. I did use some to alloy up some aluminum bronze and i did cast some stuff with them before i knew better, but I would say 2/3 of them are still on the shelf
+Sarah Perryman toss it in the garbage usually. The dross is usually impurities and aluminum oxide (alumina). Alumina can be used to make some stuff but I haven't tried any of that myself.
Paul's Garage yes it is and there about five pounds each im working on a new foundry like you have do you think that the other mix is lasting better so far
Hey paul and paul watchers ever gonna come back to the charcoal foundry? More inportantly does anyone know what kind of fumes come off of this kind of foundry setup? And how to possibly avoid those fumes?
+explosev gamr hello! I see you have a lot of questions, most of it can be answered by this link: www.alloyavenue.com/vb/showthread.php?2469-Foundry-Tutorial-Book. That goes through most of your questions. I'll try to answer what you asked so far though
Hey Paul, love the video and the humor! I kind of follow the same procedure you recommend for melting cans. I need to try adding the flux during the melt, that seemed to help pull more AI out from the dross. Thanks for the tip.
Thanks! it does help get more metal out of the dross but i'm worried that it is over fluxed . I think if i mix a bunch of heat sinks in with the melted ingots though it should balance out the mix, and i'm not sure how the flux will effect it when i mix it with copper to make aluminum bronze, but i guess i'll have to try it out and see!
great videos, Adding the copper to it doesnt help it machine better, it helps it flow better into the molds. Your ingots show it alot better between the cans/extruded aluminum to the cast where as the extuded/cans ingots were rounded at the top due to the surface tension, and the cast ingot has more of a sharp top to it where it flowed out more into the shape of the ingot tray. Adding copper to extruded aluminum does help it flow alot more, but you do get the same amount of shrinkage, and in sharp corners, you may end up with what's called hot tears, where the metal shrinks in tight corners and splits, making for a weaker part, but to overcome this, just add fillets to everything, which is common pattern making practice anyways. Also they look different because the cast ingot has had time to oxidize alot where as the new ones havnt, eventually after sitting a few months, they'll both look the same. I usually just use a sharpie to write on what each is, or just throw them in seperate buckets.
huh i heard the copper helps it machine better from someone else, but you would know better than me! Good point about the tops of the ingots, i hadn't thought about that. the cast stuff definitely seemed to flow more nicely. Good idea on the sharpie, i havent marked them yet but they are in separate piles, plus the can ingots have the really cool crystals on the surface. I wish i could get a close up camera shot of that, it would make a cool picture.
+Brendan W there are many casting alloys, but most of them contain silicon, 5-15% or more. Silicon is also found in cast iron in high amounts (different from pure iron or steel which has some carbon but not silicon). Also some modern bronzes use silicon added to copper instead of adding tin to copper like in traditional bronze.
If u add sulfur to ur flux it makes an unstable explosive please keep this in mind when doing scrap melting if their is sulfur in ur mix up can get explosive bubbles to full out bang. Use borax instead of salt if u think there might be sulfur present.
@@wd4685 yeah I've poured in all Wisconsin weathers. I've seen no difference. The metal is always good and hot and the sand is usually closer to room temperature regardless of weather. The garage is heated and back when I did this video I would just move the stuff outside while doing the pour, not long enough for the sand to cool off
How does copper melt "like sugar on coffee" if it melts at 900+ degrees while aluminum melts before 700°?. That´s the only part I did not quite get... Thanks.
idea for dealing with dross try to find a iron mesh that can sit at the bottom of the extigusher with pieces that stick up that you can grab and pull up to strain the dross. It might be a bit overkill but an idea
Very informative vid, thanks. did not catch the name of the flux you used though - can you please comment on the name and is there other fluxes we might use, seen candle wax and sawdust used with lead - might those work for aluminum too?
Hey ! I really liked your video and content in general, but I've got a question : what kind of gloves are you using ? Because where I live there are no ''high heat'' resistant gloves for sale (or at least I couldn't find a store wich did sell them...) so I wondered if it was that big of a deal if I hadn't these ''high heat'' gloves (I do have other gloves, but they can't withstand these kind of temperatures). So what would you recommend ? Should I order ''high heat'' resistant gloges on internet, or will the gloges I already have do the work ? (I do not plan to get my hands inside the furnace of course, just to get the lid on or off and to refuel)
I use a couple different gloves, don't remember which ones are in this video. one pair is just gardening gloves (100% leather), and the other is a pair of welding gloves. I talk more about them in a video somewhere about foundry safety equipment, but basically the welding ones are better. I think foundry gloves or fireman's gloves would be better yet. I don't know which high heat gloves you are talking about, but the higher heat resistant the better probably. You don't need to get your hands in the furnace to get cooked.
When I spoke about high heat resistant gloves, I hadn't any kind of gloves in mind, just a pair that can withstand high temperatures. Anyway I ordered welding gloves on the internet yesterday, that can withstand tempertures of up to 500°C (I know the furnace reaches temperatures way higher than that, but I think it'll be ok as long as I don't drop molten metal on me...). But thanks a lot for your answer !
Want to use your 3D printer to learn Sand Casting in your home shop? paulsmakeracademy.mykajabi.com/joinus
Some of the old timers used to put a thick layer of charcoal in the crucible on top of the metal working on the theory that as it burns it creates a layer of CO2 on top of the liquid metal to keep the oxygen away and prevent oxidation. The man who told me has been dead for decades now so I can't ask him what metals he used it with or how thick a layer but it might be worth experimenting with.
Makes sense.
Another way is to put argon into the furnace or to bubble it up through the metal inside the crucible.
This requires a tube that resists very high temperatures.
Some metals will rip the oxygen from the CO2 forming the oxidation anyway.
@@nyx211 True it won't work with everything.
this is easily one of the most interesting casting vids ive seen. NO ONE addresses the difference in pure vs not, and what its missing, or how to adjust it. great vid man!
+Seth Howell thanks! I only talked about the silicon content thing because I'm a massive nerd lol
Heart disease in our metals is a real problem. Thank you for being so good to your metals!
I hear you :)
after MANY hours of serching,(literally just 5) I have found my favorite TH-camr for melting mettle. your hilarious
also, how do heatsinks help? is it like the computer kind?
+explosev gamr the heat sink was just a thick chunk of aluminum to form a molten pool first. Cans are too thin and when they melt they oxidize, plunging them into an existing pool first helps prevent that.
*searching *metal
Note on aluminum can alloy
Typically it's 3003
From Wikipedia
The alloy composition of 3003 aluminium is:
Aluminium: 96.8 to 99%
Copper: 0.05 to 0.20%
Iron: 0.7% max
Manganese: 1.0 to 1.5%
Silicon: 0.6% max
Zinc: 0.1% max
Residuals: 0.15% max
Thanks for the extra research I love knowing the extra info about alloys
Glad you've progressed beyond this stage!
Yeah cans are no fun. Now only cast aluminum, and I'm about to switch to only cast aluminum wheels or purchased ingots.
Easy first steps for beginners and such without purchasing ingots or "scrapping" various objects for metals.
As someone who hasn't progressed vry far from this finding out salt works like flux is huge. Borax in my area is expensive so I've been looking for an alternative thank you vry much for your videos they are extremely helpful@PaulsGarage
You should really rethink pouring over concrete. If the aluminum spills, the heat can cause the surface to literally explode into your face. Pour over sand or dirt.
Good call. I don't live at the location in this video anymore but i'm thinking of building a sand bed for casting in the new place for sure
Mate thanks for the tip. I admire your dedication to smelting aluminium while it was so cold where you were!
Thanks!
Thank YOU very much!
I haven't watched any "Paul's Garage" for a while... I forgot how cool it is.
I thoroughly enjoy watching your videos. Not only am I learning something but I am very entertained while doing so.
thanks! i'm glad you like them :D
Thank you so much for the tip Paul! 🔥🔥👍🛠️
Percent cannot be calculated by weight but by volume because the wieghts are very different!
Only two and a half years late to your vids, but better late than never! I'm going to try the Lo-Salt tip tomorrow because you're right - the amount of dross from cans is horrendous. In fact today I ended up with a smaller alumuffin (oooh, I like that!) than the one I STARTED with, despite adding a bucketload of cans: the amount of dross (and aluminium bound up in it) was greater in volume (if not weight) than the alumuffin. Love your channel - have a sub! :)
Im glad to have seen this video, thank you for posting it. I have just started forging and using the salt on my last 4 videos i was able to reclaim ALOT of alum from my dross. Also included my first attempts of sand casting... learning alot
Useful video for beginners. Thank you.
This was fun, like the muffin pan mold,😊 forgot the Pam😊
hair dryer❤ Love your Proper English, you must be related to me we have our own family dictionary 😅 good job
Another good video Paul. If you find out what the can alloy actually is and what the silicon content of 356 aluminum is you can crush up the right amount of silicon and toss it in to improve the casting properties of the can metal. You can do the same thing by adding some aluminum from pistons because they're very high in silicon. Burning teflon is super poisonous.
Hi pete! I probably could crush up the silicon and add it to the aluminum, but i have lots of cast aluminum already and i don't want to waste the silicon. I might be able to get a hold of some junk pistons, though. Making everdur is something i want to do as soon as i get the next furnace built, though.
Thanks Paul! This a great tip! I have been collecting aluminum cans for awhile waiting for spring to start casting but was having doubts about using them because I kept hearing the same: they are a good cheap source of alumimum/they are garbage, don't use them. Relieved to know I can use them for casting projects. BTW, I enjoy many of your videos and the information you share. Thanks!
Hi stephen! this is a pretty old video, i would suggest using the aluminum from cans for making alloys like aluminum bronze, but I wouldn't use them alone for castings unless you have a mold with plenty of head pressure or something. This stuff will have a higher shrinkage rate and higher surface tension. Nothing that can't be compensated for, of course, but it's not ideal. I used these to make aluminum bronze (90% copper, 10% aluminum). It's great.
the lines you talked about comes from gasses in your mix, i've seen people use baking soda to combat that with reasonable outcomes. and the shrikage in the center of your ingots comes from having no silica (and also i think in part from the gasses)
Is it silicon carbide that's in cast aluminum? You can see it in the grain structure when you observe a broken piece. Shiny little specks. The shrinkage is natural and occurs in all molten metals to differing degrees as they cool.
I really like your humor and your videos are good
And interesting
Thank you
Paul you can make a really good cheap propane burner just look up "how to make an aluminum foundry" by the backyard scientist. mine got hot enough to melt copper easily and you wont have to deal with refilling the charcoal every few minutes and you wont have a bunch of ash to deal with when your done melting to. fair warning make sure you have a thick and durable crucible because i have all ready burned holes in some of mine. good luck.
Thanks for the tip. I'm goign to make a propane burner before too long. With hardwood lump charcoal i never get ashes in the bottom of the furnace, but it burns out so quickly i can't get the thing reliably hot enough for copper.
It’s a furnace not a foundry! Just saying.
Look out for cans with ANY moisture in them, cause if you put a can with moisture in a pool of molten aluminum you'll get a REALLY interesting explosion!!!
Thats a good advice thanks! 😅 really I mean it ✌️
Can you clean your crucible with hydrochloric acid when you're done?
Could one use a kiln with argon welding gas purge to melt the aluminum more effectively?
Thanks for posting
can you just use regular table salt? I don't know where to get potassium chloride.
Table salt is sodium chloride with iodine, it's not the same
Awesome Video Paul - Thanks. Really liked 1) The Flux Experimentation - was cool that you fluxed the dross & squeezed out a bit more Aluminum and 2) Very interesting how to gain a better quality of Aluminum by adding %5 copper. For a while I was scrapping & collecting copper. A lot of the newer electronics save on the cost by using a super thin Copper coating on Aluminum wire for electrical conductivity. So I have quite a bit of Copper coated Aluminum wire that I thought was basically crappy Aluminum. However Thanx to your video the Copper coated Aluminum wire might just melt into a slightly better quality Aluminum!!! The one thing I wandered about was the dross in the crucible - if you had thick gloves or a better pair of tongs I wandered if you turned the crucible upside down & tapped it on the cement if the dross would fall out??? Thanx Again: Shawn
Thanks! THe fluxing worked really well, i was surprised. Someone recently told me that 95% aluminum with 5% copper is called duralumin if you want to look that up. It's a pretty decent alloy. I didn't record it, but i did actually turn the crucible over and bang it on the cement to get some dross out. Not all of it came out, though. Quite a bit stayed stuck in there. I don't have a way to scrape it out, but melting cans left FAR more crud in there than melting scrap cast aluminum, so i probably won't do cans again. All the dross was a good thing later, when i did the keychain casting video the crucible actually got a hole in the bottom of it and the dross and crud plugged it up so it was a very slow drip. I was able to pour and everything without losing any significant metal out the hole. It's in the garbage now, though.
Duralumin:
3,5-5,5 % Cooper; 0,5-0,8 % Magnesium; 0,6 % Manganese,94-95%Aluminium,Si=0.2-0,5%.
(Cans are actually made from two alloys 5004 which is 1% each of Manganese and Magnesium used for the body of the can and 5182 1% Manganese and 4% Magnesium for the lid.(data from Olfounryman channel))
As you can see, your recipe with Cooper is so close...
Fighting recipe with dissolved metal crucible:mix ''liquid glass'' with refractory clay, or kaolin, or bentonite (cat litter), or chalk and paint every time before melting.Paint everything what you immerse in molten aluminium.
Works very well!And cheap...
Toto hey I'm trying to understand what you're saying but I'm not sure I do . Could you explain what you said a little better ? Because I'm really interested in what your saying.
Thanks !
would using borax done the same thing? Getting ready for my first pour!
Hey Paul, I just found your channel and your metallurgy tips are quite helpful. Now I will look around and hopefully find how you built your furnace. Thanks, Kenn
I built a new once since this video, I have a few videos on it, something about a fire brick foundry furnace in the ttle
You are really funny man! Totally enjoyed watching your videos. Keep creating awesome content:) You deserve more subs!
Thanks! glad you enjoyed :D
Space laser sound effects at 09"30! So, what was your yield in terms of weigh of cans in vs weight of cans out?
If you just use the tabs, is the quality of the aluminium better?
That was really cool and great info. Thanks
Thoughtful comments on how to reduce aluminum dross!
Been looking for a alum flux. Thanks for sharing. We are now subbed.😎⛏⛏🔥🔥
This was very informative. Thank you
You're the best Paul
Finally the answer I was seeking. Off to remelt that shiny dross with some salt. I plan to use an ugly ingot to establish my pool for can melting. Look into fireplace gear for stirrers and grabbers. My "store" bought furnace kit came with some but not nearly as durable as my old fireplace tongs.
Cut up cans, ring-pulls, tops & bottoms of cans, & the shards covered In paint dross wise, this I just got to try, aluminium seems to be the easier to start off, so looking for electric smelter 3-4 kilos yes I have plenty of beer cans, all cut up & ready for smelting any advice you could possibly offer would be gratefully appreciated, many thanks, yours truly! P/S, thanks for the flux Info.
How did you crush your cans? When I crush mine, they end up to wide to fit inside any reasonable pool of aluminum, as they stand up instead of lay flat.
+capfer77018 I have one of those things that just bolts to the wall with a lever on it for crushing cans. I think the uncrushed ones were better to melt though.
What are you using the ingots for? Either way cool video!
These ones from the cans i plan to use for making alloys (like aluminum bronze), but that cast aluminum (aluminum with silicon in it) ingot i showed at the end i'm going to use for sand casting various things, including some tools from the Gingery book series i mentioned in some other video.
Paul, would you know if you could successfully use your foundry as a black Smith forge to make knives and such?
+ajinthevalley NS probably yes. The burner would work fine and it can get the metal to orange hot, but you would need better insulation if you want welding temperatures. Also the design is meant mainly to hold a crucible so the shape might not work for holding certain work pieces.
What happens when you drastically overheat aluminum can it be remounted and be good
Oh, that would explain why the can tabs are more sought after than the actual can is, because those are apparently more pure aluminum??
Cool video, thanks man!
I believe it's because the can has a plastic liner, and the tab does not, so it's easier to recycle
What about crushing cans, could it help?
Yup I’m definitely happy I kept a goodly amount of old 400mh lamp ballasts
Tonnes of aluminum and a tonne of copper
Sad I sold the first batch of copper rather than melting it to pure but atleast I kept all the aluminum shades and ballasts 😊
hey Paul what metal container did u use to melt the aluminum in?
In this video i used a steel crucible, but i would actually recommend not using steel. The thing died after the very next use (the keychain video) and now i have to replace it. I would suggest a graphite clay crucible for melting anything.
When you mix materials is important to consider if you are supposed to be mixing by weight or by volume. For example the same volume of copper might weigh 3 times as much, as you've shown. So when you say add 5% copper, you need to specify that you mean by weight, and not by volume.
Can you use dross as aggregate in a refractory?
Can you use Borax as the flux in melting the aluminum?
Can that homemade smelter melt copper
your self commentary is brilliant
Thanks! glad you enjoyed :D
Why would it be difficult to add silicon to your aluminum (post-slag removal)?
@beefan1596 silicon is difficult to get and is unlikely to dissolve quickly in the melt. It would have to dissolve, not melt, because it gas a very high melting point. You CAN add a hypereutectic (oversaturated solution) aluminum-silicon alloy to it in the form of cast aluminum pistons, but getting the mix right is a bit tedius, and then you will still have some contamination. Definitely doable, but at that point just buying a345 ingots becomes much easier. These days I buy basically all the metal I use, but when i made this video I did more scrapping. Buying good metal instantly improved my castings
@@PaulsGarage Would turning it into a fine powder help, by any chance? Just asking out of curiosity - I'm not planning too hard on doing it myself; I have a decent supply of scrap aluminum already (although most of it is an alloy meant for machining rather than casting).
nice video man i'm getting started in aluminum casting and really you give me some nice tips that i didn't know any thing about keep up the good work
Thanks! glad i could help
Does this salt method work with all metals?
Hey Paul please tell me what can I do with chrome glass
Not sure, sorry!
thanks for the flux tip, i have some large chunks of aluminumy dross i might try to reheat later
You're welcome! I was able to pull a lot of aluminum out of the dross, even after fluxing it a lot the first time, you should have good luck.
I have a bunch of small ingots from melting cans. Can I just use one of those to start the precursor pool, or does it have to be a higher quality aluminum?
yeah that should work fine
Amazing video! Was actually surprised, I subed and liked your video!!
That's a really nice big chunk of silicon you've got there!
+edgeeffect I'm trying to resist the urge to flintknap it. Imagine a chrome arrowhead!
Hey Paul - Paul here... good tip with the copper addition to the aluminum. I'm casting sculptures, and was wondering how to do away with shrinkage... mostly notice it in the Sprue, not the cast pieces below. I'd hate to find out the hard way. Subbed.
+zillustration hi Paul! Adding copper won't really help shrinkage as much as silicon, and aluminum will always shrink somewhat. If your sprues and risers are of sufficient size/locations, you shouldn't have damage to the piece. Are you doing lost wax or something?
search zillustration or paul zdepski on FB - i have some public on my page... plus pics of my furnace. Will be trying lost wax, but currently using Super Sculpey to make my models, then casting in fine green sand. A friend of mine is a jeweler, so he's got the super fine stuff. Great detail with finer sand.
With the copper, would a layer of oxidation be an issue like with the aluminum do you suppose?
+Cheerfultrout yes, in fact copper oxidizes more aggressively I believe. People often use cover fluxes or stuff charcoal in the crucible to take up the oxygen when doing copper.
Have you tried adding a bit of charcoal or coal to the crucible in order to consume the oxygen and prevent oxidation, or do you think it would just add to the impurities?
+David Nielsen I did just that for the copper melt I did, but for aluminum the aluminum oxide skin is somewhat protective
cool. Thanks
Thank you for being entertaining. Now to see if you have anymore videos....
Did you try plunging soda ash into the aluminium?
love the new video i wonder if you chemically treated the cans before to remove the paint and plastic if you'd end up with a lot less dross the pans i use are extruded and im 90% certain pure aluminum and i generally get very little dross. i think surface area has alot less to do with it and its mainly the vinyl paint, and plastic coating that is responsible for the dross.
Thanks! I think you are right, the plastic is the main problem. i'm sure there is a way to remove the coating with something, but i think just using extrusions is probably easier. there is so little metal in a single can that i doubt it's worth the effort.
no, if you remove the coating, you expose more aluminum to the air before hand, which will cause even more oxidization before you even get to start melting it. Most of the dross is from the side walls of the cans due to such thin aluminum. Try throwing aluminum foil in a fire, its like that. If you wanted maximum metal out of cans, you would just cut the tops and bottoms off of the cans and use only those, the side walls dont really have any metal to them.
thats a good point, the sides of the cans are stretched pretty thin, and the plastic would form a nice barrier. I bet as the plastic burns it would eat up some of the oxygen in the can, too, preventing the aluminum from oxidizing. the top is a different alloy, too, if i'm not mistaken, but it's just a couple percent manganese or something like that.
Paul, is the silicon used to make hard drive platters the same as the silicon you're speaking of?
possibly. Pure elemental silicon has many uses, including as an alloying agent, but it's not particularly easy to find.
KyHighlander59 i think you can make it using thermite
No- that is a thin, polished iron oxide on aluminum platters that you're thinking of. There is very little silicon in hard drives (only minute quantities inside the solid state devices (chips, transistors, diodes, etc)
when you ram up the furnace lid prop the steel band up 1/2 inch above the bottom face of the refractory. this will keep the steel hoop cooler and it won't expand so much.
where did u find the 10 qt steel bucket and the 2.5 qt bucket? i can't find em anywhere
+Dante Kania I got them at a home improvement store, specifically Menards.
I made the plaster and sand furnance today but i didnt make the lid, il it make to much of a difference for aluminium ?
the lid would help it melt aluminum faster, but it will still melt. there is a guy named makerj101 who used an open fire for aluminum casting, so hot lump charcoal isnt even required.
Paul's Garage ok thanks
I've been saving all my aluminium-y dross looking for a means of "refining" it.... I'll flux the crap out of it next weekend.
So you can fish the crap off of the top before you pour it, I've been doing that and it's made pouring much easier. I just smashed some scrap steel to make a spork type thing with a long handle to fish it off. Plus it's fun to play blacksmith and hammer stuff.
I've never done the lite salt, but that is pretty great. I'll have to do that with my next batch.
The scooper is a good idea. I need to make one of those up. The spoon with channel locks just isn't capable of getting the dross out with the cans, there was just way too much of it. The dross left over is non-metallic though so that's nice, i think i got all the aluminum out with the lite salt.
So regular table salt?
So What do you do , with the Dross ! Then ! ??
garbage can. and this video is super old, i wouldn't recommend melting cans at all anymore. too much oxide waste, too much dross from the plastic can liner, and it's not the right alloy for casting
@@PaulsGarage The Garbage can ! Sounds Quite Bad ! For the Environment ! And Alloy !?? I don't know About that !
yeah cans are made from 2 alloys, neither of them flow well for metal casting. A356 is a good flowing aluminum alloy but it can't be formed into cans. You find that stuff as car wheels and some engine parts.
@@PaulsGarage So what did you do , with the Buttons ! ( From the Cake tin In the video , ones ) then ??
@davidwillard7334 still in a pile on the shelf, unfortunately. Most of them anyway. I did use some to alloy up some aluminum bronze and i did cast some stuff with them before i knew better, but I would say 2/3 of them are still on the shelf
What do you do with the dross afterwards?
+Sarah Perryman toss it in the garbage usually. The dross is usually impurities and aluminum oxide (alumina). Alumina can be used to make some stuff but I haven't tried any of that myself.
I use a pound cake pan and make like big bars out of them
+mark hodsdon that sounds pretty cool!
Paul's Garage yes it is and there about five pounds each im working on a new foundry like you have do you think that the other mix is lasting better so far
+mark hodsdon yeah this mix is working great. No signs of damage after almost a year
Paul's Garage cool thats what ill do and i subed
Do you make "like" big bars, or just big bars?
to filter the crap on the top try cutting a steel plate to sit on top to strain the stuff
That's a good idea, has to beat a spoon with pliers like i used lol
Put a spout on the crucible so that you actually pour from near the bottom (like a gravey bowl).
Actually gravy boat I think?
I make my initial pool with bits of cast aluminium.... don't know if that helps much at all but it's what I do.
Borax makes an amazing flux for this process.🤠👍😁
A longer mixer might be a good idea!!!.
Does mixing salt into the aluminum change its properties much?
Hey paul and paul watchers ever gonna come back to the charcoal foundry?
More inportantly does anyone know what kind of fumes come off of this kind of foundry setup? And how to possibly avoid those fumes?
Nope, I gave the charcoal foundry away to someone. The fumes are probably the same as a charcoal grill, plus whatever comes off the metal being melted
how do/ what can you do to prevent oxidation, and flux
what is dross
what do you mean by pistons
+explosev gamr hello! I see you have a lot of questions, most of it can be answered by this link: www.alloyavenue.com/vb/showthread.php?2469-Foundry-Tutorial-Book. That goes through most of your questions. I'll try to answer what you asked so far though
Hey Paul, love the video and the humor! I kind of follow the same procedure you recommend for melting cans. I need to try adding the flux during the melt, that seemed to help pull more AI out from the dross. Thanks for the tip.
Thanks! it does help get more metal out of the dross but i'm worried that it is over fluxed . I think if i mix a bunch of heat sinks in with the melted ingots though it should balance out the mix, and i'm not sure how the flux will effect it when i mix it with copper to make aluminum bronze, but i guess i'll have to try it out and see!
So is pure aluminum better for mixing with Copper to make Aluminum-Bronze?
Yes! Cast aluminum has silicon in it, and silicon-aluminum-bronze is a slightly different color with different properties
great videos, Adding the copper to it doesnt help it machine better, it helps it flow better into the molds. Your ingots show it alot better between the cans/extruded aluminum to the cast where as the extuded/cans ingots were rounded at the top due to the surface tension, and the cast ingot has more of a sharp top to it where it flowed out more into the shape of the ingot tray.
Adding copper to extruded aluminum does help it flow alot more, but you do get the same amount of shrinkage, and in sharp corners, you may end up with what's called hot tears, where the metal shrinks in tight corners and splits, making for a weaker part, but to overcome this, just add fillets to everything, which is common pattern making practice anyways.
Also they look different because the cast ingot has had time to oxidize alot where as the new ones havnt, eventually after sitting a few months, they'll both look the same. I usually just use a sharpie to write on what each is, or just throw them in seperate buckets.
huh i heard the copper helps it machine better from someone else, but you would know better than me! Good point about the tops of the ingots, i hadn't thought about that. the cast stuff definitely seemed to flow more nicely.
Good idea on the sharpie, i havent marked them yet but they are in separate piles, plus the can ingots have the really cool crystals on the surface. I wish i could get a close up camera shot of that, it would make a cool picture.
Wish my locations would allow this. The local yards (USA-TN) will not take them.
What's the difference between cast and pure aluminum
+Brendan W there are many casting alloys, but most of them contain silicon, 5-15% or more. Silicon is also found in cast iron in high amounts (different from pure iron or steel which has some carbon but not silicon). Also some modern bronzes use silicon added to copper instead of adding tin to copper like in traditional bronze.
This is the Perfect YT Video. How many years have I thought about it, wondering about it
not sure if bot comment...
@@PaulsGarage Again.... LIES! Your TWO BOTS won't even let you mindlessly click thumbs-up on your YT video comments!
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If u add sulfur to ur flux it makes an unstable explosive please keep this in mind when doing scrap melting if their is sulfur in ur mix up can get explosive bubbles to full out bang. Use borax instead of salt if u think there might be sulfur present.
What kind of pipe did you use to stir
It was just a metal pipe i had lying around, nothing special
Is it normal to hear faint cracking after crucible has been tempered and is cooling off?
Have you poured in winter? If soo is there a difference in how it handles
@@wd4685 yeah I've poured in all Wisconsin weathers. I've seen no difference. The metal is always good and hot and the sand is usually closer to room temperature regardless of weather. The garage is heated and back when I did this video I would just move the stuff outside while doing the pour, not long enough for the sand to cool off
Hey bro. How do you go about removing hard solidified copper from graphite crucible
Awesome. Thank you.
How does copper melt "like sugar on coffee" if it melts at 900+ degrees while aluminum melts before 700°?. That´s the only part I did not quite get... Thanks.
The suger is not melting, its dissolving
Many danger exists between your Mom's tits!!! For one, I'm joking so you may now laugh little one...
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idea for dealing with dross try to find a iron mesh that can sit at the bottom of the extigusher with pieces that stick up that you can grab and pull up to strain the dross. It might be a bit overkill but an idea
that would be pretty nice. the mesh would have a ton of surface area though and i would be worried about the steel dissolving into the aluminum.
@@PaulsGarage Lies! Your TWO DADS won't let you pour aluminum muffins ALONE!
Very informative vid, thanks. did not catch the name of the flux you used though - can you please comment on the name and is there other fluxes we might use, seen candle wax and sawdust used with lead - might those work for aluminum too?
it's Lite salt/Losalt, basically just low sodium table salt from the grocery store. I'm not sure sawdust or candle wax would work with aluminum.
Love your channel
Hey ! I really liked your video and content in general, but I've got a question : what kind of gloves are you using ?
Because where I live there are no ''high heat'' resistant gloves for sale (or at least I couldn't find a store wich did sell them...) so I wondered if it was that big of a deal if I hadn't these ''high heat'' gloves (I do have other gloves, but they can't withstand these kind of temperatures). So what would you recommend ? Should I order ''high heat'' resistant gloges on internet, or will the gloges I already have do the work ? (I do not plan to get my hands inside the furnace of course, just to get the lid on or off and to refuel)
I use a couple different gloves, don't remember which ones are in this video. one pair is just gardening gloves (100% leather), and the other is a pair of welding gloves. I talk more about them in a video somewhere about foundry safety equipment, but basically the welding ones are better. I think foundry gloves or fireman's gloves would be better yet. I don't know which high heat gloves you are talking about, but the higher heat resistant the better probably. You don't need to get your hands in the furnace to get cooked.
When I spoke about high heat resistant gloves, I hadn't any kind of gloves in mind, just a pair that can withstand high temperatures. Anyway I ordered welding gloves on the internet yesterday, that can withstand tempertures of up to 500°C (I know the furnace reaches temperatures way higher than that, but I think it'll be ok as long as I don't drop molten metal on me...). But thanks a lot for your answer !