Silvery gray scum

[Tech2]

I melted down some spent shot tonight. A large amount of crumbly gray oily scum was floating on the top. It coats my spoon and hardens when cool. a brownish oil seems to also be slowly coming to the top. It doesn't want to flux back in.
The ingots are shiny and or frosty with lots of antimony floating on the top.
Anybody know what this scum is?

[220swiftfn]

Graphite??? As to the oil, it could be just that, you have no idea how the shot was reclaimed. I'd suggest using a lot of sawdust, skim the dross that's left, and don't worry about the loss, just get it clean......


Dan

[runfiverun]

graphite:
you'll see your boolits have a grey like color to them too.

[Tech2]

I mostly wanted the shot to alloy with and the ingots look clean. I just needed to know if something important or dangerous was coming out of the melt.
It could be graphite and a binder but not just graphite it has a very high melting point.
http://i755.photobucket.com/albums/xx196/hansen_acura/dross.jpg
Dross and the coating it left on the spoon

http://i755.photobucket.com/albums/xx196/hansen_acura/ingots.jpg
The ingots look clean

[badbob454]

looks like you did a good job the dross is a toss and the ingots look great , if you save your dross from all your smelting ,if you do alot of smelting .. you can remelt it all together to reclaim a small amount of lead ..., but if you dont save the dross, toss it out..not worth re heating a small amount

[220swiftfn]

Are you using Borric acid as a flux??? (Frankford Arsenal, etc.) That kindof looks like it.... Coats everything too.... Either way, I'd still suggest using a lot of sawdust or pine bedding, not only does it flux the melt wonderfully, the ash that's left binds to the dross so it's powdery and doesn't stick to everything......


Dan

[Tech2]

I use red wax from baby bell cheese snacks for flux. A guy at work saves them up for me. I would have added some saw dust I just didn't have any clean and dry enough to use. I'll find some for the next batch.
http://i755.photobucket.com/albums/xx196/hansen_acura/wax.jpg
The wax from three pieces of cheese

[runfiverun]

that would explain the black coating.
burn the wax off [light it on fire in the pot] once it gets melted and you stir it up well.
i use wax to burn the sticky tape off from stick on ww's in the smelting pot otherwise it's a mess.

[Tech2]

The wax burns clean with a little soot left on the side of the pot.
This stuff is greasy looking even after the wax fire. It makes a hard shell on the spoon when it cools

[popper]

re-smelt that with sawdust to get the remaining metal out. You did take the plastic out before you melted, right?