Second session of melting

Well I didn't get any photos but I did get around to melting some more scrap aluminum. During my first melting session I noted that due to the size of the furnace I had made that it was evident that I needed more heat to get things moving along so I made that adjustment this time around. I started out with a good solid layer of charcoal on the bottom of the furnace four deep and got that burning. While that was getting started, I got some additional charcoal started in my fire pit and set the crucible into place in the furnace to start pre-heating the crucible. Once all of the charcoal was going good I added charcoal around the sides of the crucible about two-thirds of the way up. As soon as I accomplished that task I added scrap to the crucible, set the lid in place and got my air flowing into the furnace.

I checked on the progress after about 20 minutes and found a nice pool of molten aluminum in the bottom of the crucible! At that point I turned off the air, removed the furnace lid and spooned off the slag then added more scrap. Filling the crucible with a bunch of crushed cans the first thing I noticed was that the cans caught fire and melted within no more than 30 or 40 seconds.............NICE!

I repeated that cycle once more and found that I was losing heat and the melting process was slowing down so after yet another addition of scrap I put the furnace lid back on and got the air flowing again. Within a few minutes I had the temp back up and was melting scrap very easily again. I kept this cycle going until I had melted down an entire bag of crushed aluminum cans, which sounds like a lot of aluminum but there is also a lot of slag in the cans and my guess is that I got about a quart of aluminum melted from the one trash bag of cans, which I poured into a muffin tin to make ingots. It was only 12 degrees or so outside and by the time I poured the last of the crucible I was losing the heat in the metal. My hope is that I am cleaning up the scrap in making the ingots so that when I melt them again to pour a project I won't have so much slag to deal with.

After melting the bag of aluminum cans I decided to see how tin cans would melt, so I added charcoal to the furnace and got the heat up again. I loaded the crucible with tin cans and checked on them after 20 minutes or so in the furnace. They were glowing but no where near melting so I opened up the air and gave it a good blast, which in very short time only succeeded in blowing a hole in my crucible! In adding that much air I oxidized the mixture and killed my crucible. Kind of impressive for a charcoal powered furnace, but not what I was looking for!

So now I will have to wait for the weather to warm up and make another crucible before I can resume converting my scrap into ingots........................ I wonder what I would get if I added some tin cans to the melted aluminum.............Hmmmmmmmmm

until next spring then!