how do skim the dross off when melting aluminum cans? any techniques?
awhile ago i tried melting cans for the first time. i had lots of crud and couldn't skim it. i think part of my problem was i didn't have enough fuel and maybe the temp wasn't hot enough. the aluminum stuck to my improvised skimmer. i tried removing the aluminum from the skimmer by wiping it in molding sand but that just made things worse.
anyways, i couldn't pour the aluminum out of the soup can. after it cooled i peeled off the soup can. all i have to show for my effort is a chunk of aluminum with a bunch of crap embedded into it. not worth re-melting. i was just trying to make ingots.
I'm just guessing but what you used to melt the cans had an open top exposed to air. What I see looks like you had way to much oxidization. Aluminum loves to oxidize and once you get it instead of 1280F you are looking at 3700F to melt it. So some tips.
Melt under a hood. (Let the combustion byproducts take care of the O2.)
Don't skim. Just like on an aluminum cookie sheet the oxide layer protects the rest.
Once the melt has started push the can down blow the surface. Its going to create some oxide give it as little chance as possible.
The Inks and organics are long since gone once you see that scum.
Aluminum melts at 1280F but is almost always poured (even for ingots) at 1350-1375.
Hope that helps a little. I've never done a melt at home.