Hi, I've got a bunch of cans I would like to smelt. They are starting to take waaay to much space and it's about time I get to it. What do I need to do that efficiently. I would like to avoid some very advanced setups ( for now at least ) Thanks
If your purpose is to sell the aluminium. I would just crush them they will be worth the same and the person buying them will know exactly what alloy they are getting. You will alo save alot of time and money (fuel) and wastage due to oxidation during the melting (not smelting) process.
Recycle/scrap them, they are very smokey/messy as well as labour intensive to melt, and offer a poor yield. In addition the metal quality for any casting purposes is poor, it's an extrusion alloy not a casting alloy. The reason for the smoke is the polymer lining that keeps the contents from eating thru the can as well as the paint on the exterior If you absolutely must melt them, crush them as flat as you can get them. Preheat each one on your furnace lid to dry them and get the polymer burning -they must be dry before they go in, moisture and molten metal do not mix. Once you get a puddle at the bottom they will melt a lot faster. You will need to clear the dross out periodically as it accumulates quickly. Avoid filling a crucible and just firing it, the dross is so excessive it will just be a pot of mush with a bit of overheated liquid metal at the bottom. And again it's smokey as can be with noxious fumes from the liners burning - do this outside Melting good cast scrap you do not have any of these concerns
Welcome. What you want to do is melt your cans. Smelting implies refining ore. That’s something different altogether. You can simply dig a hole 18"diameter, 16"deep and fill it with charcoal. Bury an 18" piece of exhaust pipe at a downward angle to get air to the bottom of it by means of an old hairdryer set on low. A steel quart paint can or fire extinguisher (this is better) with the top cut off will suffice for a crucible. Bury the crucible most of the way down in the center of the charcoal-filled hole and let it rip. You will have to replenish your fuel so have wood or charcoal handy. PPE is mandatory and moisture is enemy #1. Learn more about safety before you do it. This shit will burn your house down and/or permanently injured you. Make sure your cans are bone dry before submerging them. Expect at least 50% loss by weight. I know we sound like a broken record but guys here will always try to steer you away from drink cans, and with good reason. The paint and varnish are the real culprits. If you just want to make some pucks and don’t care much for the quality of the metal, old school lawnchair tubing, broken triple-track storm windows, broken ladders, etc will work way better than cans. Pete
@Mantrid The purpose is to actually do it since I've been saving those cans for more than 2 years. @Rocketman Could you expand on that please. I mean I can't be 100% sure there isn't some liquid inside those cans. Preheating them could prove difficult since I do not own a furnace. @Petee716 I just want to try and "recycle" one bag of those cans myself so I would go with the 18 by 16 inch hole in ground and crucible from an old fire extinguisher. What about tools ? How can get the slag from the crucible and what can I do with it afterwards. Also I would like to have some sort of rudimentary mold to pour the melted aluminum into. How can I make that ?
The hole diameter doesn't have to be that big. 3-4 inches of space outside the crucible is ok. A stainless serving spoon from the dollar store will work for skimming. Lift and pour with channel locks. Welding gloves, long cotton clothes, leather boots, and safety glasses are all required. I use cupcake pans to make ingots. Avoid teflon. Burning teflon will make birds fall from the sky. No joke. The volume ratio of water to steam is 1:1600. That means 1ml of water turns into 1.6 liters of steam instantly. Not real-fast. Instantly. That means if moisture is submerged (entrapped) in molten aluminum at 1250F it will explode. It is imperative that anything you push under a pool of aluminum is dry. Therefore moisture and molten metal do not mix. It even hides under the layer of rust on your cupcake pans so preheat those to red hot at the beginning of your melting session. Shake your can out, drop it in the crucible for a couple seconds and then push it down with a potato masher. Do this for every single can. Stay upwind, it's smokey. I'd recommend watching a bunch of videos by Myfordboy. He doesn't melt cans in a charcoal fire hole, but his demonstrations are very instructive. Pete
I side with Petee. Hit up your local used goods/thrift store(s) for a stainless spoon or two, (the longer the handle, the better), and a couple steel cupcake pans. Snag a pair of barbeque or fireplace tongs, too, for placing your stock into the crucible. YOU DO NOT WANT A STEAM EXPLOSION!! That will throw molten aluminum all over the place, including on you, and start fires if dry enough. And you can pre-heat.....just set them around the rim of your firepit to get hot before placing them in your crucible. Watch some youtube videos, especially the ones that we would make fun of. There's a lot to learn from them, like how NOT to do things. (No athletic shoes!) Crushing them flat will give you a bit better yield. The problem with cans are that they are soooo thin, and a large percentage of the metal gets badly oxidized before it melts, and this gives you large amounts of dross to skim, compared to heavier thicknesses of aluminum. Best is if you could round up some cast aluminum scrap to break down. Stay safe.....Roger
Just once was more than enough for me, it was actually more unpleasant than everyone had told me. I'd underestimated how not fun crushing then drying then adding then submerging one can at a time for about an hour before having a full crucible half full of dross to deal with. The 'better' yield you can get from jumping through these hoops is IMO really a 'less terrible' yield. But... You absolutely can melt can metal and pour it into a mold to get a shape something like the inside of that mold. And I never saw anyone who's been saving cans to melt get talked down from trying it. So I won't spend any more time than I already have trying. Good luck! As for simple molds, you could try lost foam casting, aside from a way to melt and pour metal, all you really need to start making some crude castings is a bucket of dry sand and to carve some styrofoam into the shape you want to cast. Or you can buy some cheap decorative premade styrofoam shapes from a craft store to try casting. You can find more details on the exact process if you hunt around here a bit. Lost foam casting can make really nice castings if you do it right (see Al3O2's lost foam posts) but a simplified version of it can also work to make some things that might be a bit more crude, with very little up front costs or equipment. Jeff
As someone who occasionally needs to learn things the hard way, I understand orglee's desire to melt his cans and I'm not going to discourage him. So, I say to him, go for it, have fun but PLEASE, take heed of the warnings others here have given and do it safely. I suspect, like Jeff, you'll probably only want to do it once.
