Hobby metal caster looking to buy metal (SE WI)

I think Ali cans are the wrong grade for casting, also Hard drives are made from 'Extrusion grade Aluminium'.



They cut off a chunk of it, heat it up till its nearly molted, then drop it into the casting machine and 'STAMP' the top 1/2 of the die drops and squeezes the soft Ali into the shape of the casting mold. Its called 'High pressure casting' or something like that.

Some grades of Ali, when molten, flow like liquid porridge, all chunky molten liquid lumps.
Anything that's a 'sand cast' Ali casting would be good material to cast from, except the Hard drive chassis and lawnmower chassis, because they have a lot of some other metal in that (Copper?) To stop corrosion.

I'd stick to engine/gearbox Ali castings. Anything thick is going to have less oxides on it too.

Thanks parrothead, I hadn't thought of it like that. I can't find an edit button, the FAQ page says "Your ability to edit your posts may be time-limited", am I too late to change my first post?

I have never tried casting with aluminum cans, they don't sound like they're very good for it. What I've read is that a lot of the material is lost to oxidation and has to be skimmed off because it's such a thin material, and that there's a risk of steam explosions/splashing if there's still some liquid inside of them. I also don't want to sit there feeding them into the furnace one at a time, either. Any alloy can be cast, but cast alloys have silicon in them, which makes them pour and fill details better, and also reduces shrinking and the tendency to tear while cooling. Cans and extruded alloys don't have silicon, they can still work for thicker castings though. Just more time intensive.

I know there are a lot of places I can check with, I was just hoping to avoid calling/driving around to multiple spots for uncertain results, I was kind of surprised at scrap yards not wanting to sell me stuff last time I tried looking for metal. I work as a machinist (often 50-60 hours a week) and am not a scrapper, I was hoping I wouldn't have to spend any time 'hunting' for material. Oh well, thanks everyone.