I haven't made a furnace yet. Still thinking of buying one instead. Perhaps a high temp electric kiln in case I want to get into pottery as well.
I was just wondering about flux. Do most people use this for melting aluminum cans and stuff or can you get by without it and just scrape the crap off the top?
Pete
Do it all the time - and BTW cans are terrible scrap in general, you should grab something with dimensions. Tubing, extrusions, screen doors...
Tim
-- In the immortal words of Ned Flanders: "No foot longs!" Website @
Do "what" all the time? Use flux? Or go without it and just scrape the crap off?
Maybe I'm wrong, but for some reason, the aluminum recycling place seems to pay more for cans than extrusions. Is that because the melting process of the larger companies can more easily melt the cans and remove the crap - then can a little guy?
Yes! :^)
That is to say, I've never fluxed the melt. Seems to work just fine.
Meh, who cares, give 'em the dang cans and buy scrap back from them for cheap :)
Tim
-- In the immortal words of Ned Flanders: "No foot longs!" Website @
Cans are almost pure aluminum and are all the same alloy. With other mixed scrap, the smelter has to take a hit on the price he gets when it's all melted down, the stuff has to be analyzed and additions made to make whatever commercial alloy is wanted out of the stuff. Cans get melted down to make other cans, they're worth more if kept segregated.
The rule for scrounging casting scrap is to find some cast scrap object like what you want to cast and use that for source material. For making pistons, get some scrap pistons; for engine heads, get some old VW heads, etc. Like I said, cans are almost pure aluminum, mechanical properties suck, it's also gummy and hard to machine. Great for drawing can blanks, though. Wrought and extruded alloys may cast OK, but odds are against it without additions to the melt.
Stan
Cans are almost pure aluminum and are all the same alloy. With other mixed scrap, the smelter has to take a hit on the price he gets when it's all melted down, the stuff has to be analyzed and additions made to make whatever commercial alloy is wanted out of the stuff. Cans get melted down to make other cans, they're worth more if kept segregated.
The rule for scrounging casting scrap is to find some cast scrap object like what you want to cast and use that for source material. For making pistons, get some scrap pistons; for engine heads, get some old VW heads, etc. Like I said, cans are almost pure aluminum, mechanical properties suck, it's also gummy and hard to machine. Great for drawing can blanks, though. Wrought and extruded alloys may cast OK, but odds are against it without additions to the melt.
Stan
I heard they were around 2000 series. Pop cans are definetly not pure aluminum, as I have some (try finding some AWG #0 or so aluminum wire) and it is SOFT. It's like, hard clay. Popcans have strength as-cast.
I've found cast alloy in, lesse, engines (manifolds, blocks (e.g. dead mowers), heads..), and uh anything that looks cast. I recently scrapped an old microwave whose door was cast aluminum! Wish they still made things so robust.
Extrusion isn't bad as I recall, an old 200-2000W car amp is a good source. Screen door frames and such are popular too.
Plate and some extrusion (again, IIRC) is 6061 or so alloy, it's made for forming not casting, so it's soft as-cast and is work hardened or heat treated to get its strength.
I once melted some plate and cast it into a thicker piece (5/16") which was to be bolted down spanning a gap, such that it would be pulled through if it were torqued down real far (and if the bolt had that much travel), well anyway after torquing it down then removing the bolt, I freshened up the surface with a file and found the once-flat surface had a nice circular depression in it surrounding the bolt! And I didn't tighted it THAT much!
Tim
-- In the immortal words of Ned Flanders: "No foot longs!" Website @
Not necessarily so! When Aluminium Romex first came on the market, the insulated conductors were dead soft, but heaven help anyone who tried to twist the bare ground wires together, or even bend them twice. Gerry :-)} London, Canada
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