Is painted aluminum usable for melting? Yes!
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- čas přidán 6. 09. 2024
- Painted, annodized, and oily aluminum scrap melts just like bare aluminum, but with two differences - the surface impurities burn off as toxic smoke and/or ends up as dross.
Thought you'd like to know.
When I started melting aluminum,this is one of those questions I worried about.
@TOSViolator
Good note. And in general, I'd agree melting stuff should be done outside with the open breeze to take fumes away. Even if I wasn't melting anything, it would be dangerous to run a propane burner inside. Propane creates CO and water when it burns. Carbon monoxide builds up very quick in an enclosed space and could kill you. It's also very surprising how much moisture comes off a propane burner - enough to cause things in your garage to rust if you ran the burner indoors.
My understanding is that most of the dross comes from the painted and exposed surfaces of the aluminum. The large surface area of a soda can has oxidized before you crush it. So crushing wouldn't reduce that dros.
Yes, cans melt easily. But since they have a lot of surface area, a large percentage of the weight is oxidized material, which becomes unusable dross.
So if you have a lot of cans, you can melt them down for sure, but the yield will be lower and you have to scrape off more dross.
A thick steel pipe welded up works fine for most people, especially if you have a welder and want to build it yourself. A quick web search should turn up crucible recipes if you want to make something out of clay. But they're cheap enough that it I prefer to buy my crucibles. The one in this video came from eBay.
It's a clay-graphite crucible I purchased. There are plenty of DIY plans on the internet for building your own crucible. Most people DIY the furnace, but buy a real crucible.
I am unsure if some of the dross comes from allowing the surfaces to be exposed to air while they melt. It seems to reason that this causes some additional oxidizing and hence, causes some of the dross. If this is true, then crushing them, or alternatively submerging them in the already molten pool of aluminum should reduce the amount wasted as dross.
Someone more expert, perhaps a professional will have to comment on the effect.
The crucible is clay-graphite.
Will crushing the cans reduce the dross?
Can I crush the cans, toss them in my fire (it melted my wife's al frying pan by accident once), and rake out the pieces of melted metal and then re-melt them in a crucible to do the dross thing and pour into sand mold?
I figure I can do the re-melt later that way and just temp. store them as lumps of carbon and AL.
???
Is that likely to work
@panzuman
I made my crucible from stainless coffe can, works fine for me, thin wall is getting fast hot so dont have to wait long till aluminium melts. Btw im pouring ingots for now and today was my first pour. all worked good, my question to amaedesign is how long it takes by you to melt down some Aluminium. I want to know if my furnace is not too slow, by me it takes 30-40 minutes when crucible is full
when a sunkist has just a little liquid left, it smells really good while it is burning away. anywho, what material did you use for the insulation/refractory.
whats your crucible made of?
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