Casting From Aluminum Cans

**snapperhead** · 08-16-2014, 03:11 AM

A furnace for small quantities of Aluminium, can be as easy as the pail and charcoal furnace mentioned above. The key to getting to meting temps quickly is having a blower of some sort to inject air into the fire under the crucible, people have used hair driers, leaf blowers, shop vacs, and air compressors for the job. Searching google images for "charcoal furnace for aluminium" should show some easy setups for you.

Aluminium cans are not the best to start out with if you want to try casting into shaped ingots. You get lots of dross from the inks and coatings on them, and you need to melt lots to get any substantial amount of molten ali to cast. It also doesnt have the silicon content in it that allows it to pour smoothly into molds (it is like pouring porridge). One more downfall with cans is the high chance that there is liquid in them, if submerged under molten aluminum, it will cause a vapour explosion and spray molten aluminium everywhere including you. Great care must be taken to pre heat cans to burn of any water before going into a molten pool of metal, the pop happens so quickly and its not a good thing, trust me on this one.

Some of the best casting Aluminium is from things like lawn mower chassis and engine parts, also car engine parts like inlet tracts, heads, manifolds, housings, etc are great for casting too. Anything that has been cast before has the right chemistry to pour (fluidity and shrinkage rates).
The worst are cans, all extrusions, sheet and tube (too pure and lacking the silicon content for pouring into shapes, plus high shrinkage)

My advice would be to avoid the cans for melting (as I do) and go for the lawnmower and engine parts. Much less waste (dross), a faster melt, and 9 times out of 10, you will get an ingot you will be happy with.
That said, I did my time melting and making ingots from cans, it was a valuable part of the foundry learning curve and taught me many things, if only by comparison and mistakes learnt.
Pouring molten metal into new shapes can be addictive, get stuck in and stay safe.

**PickerBenny** · 08-17-2014, 06:23 PM

Thanks for the info, now i know! Ill keep my eyes out for lawnmower cast aluminum blocks..

**rlbob1** · 09-24-2014, 03:19 PM

Well you are in luck. I have a Youtube video that shows you the furnace and a series of tutorials that go into great detail how to make one. It burns propane and can melt up to 100 cubic inches with the extension added. Or less with just the base and the lid. I do not recommend using cans since they produce too much dross (oxide). Use old ladders, mowers etc. The video and the tutorials can be found at my Youtube channel rlbob1 under metal casting. I will go ahead and embed the most popular of the 4 videos so you can see what you are getting yourself into.