Casting question

[KingBee]

I've been casting bullets for a few years, using scrap lead, for a couple of blackpowder rifles. Well, I ran out of scrap, so I bought 50 lb. of 20 to 1 alloy from Rotometals. I've had greenish-yellow, crumbley stuff floating to the top of the pot all day. My bullets seem to have bits of something in them, causing a roughness to the surface. My Lee 4-20 melter was sandblasted clean before I put in the new lead, and the mold (Lyman) was producing good bullets a week ago. I assume that the roughness and the greenish-yellow crud are related, but I don't know what to do about it. Does anyone here know what's going on?

[Paul5388]

Many compounds the color you're describing are copper of some sort. That doesn't mean all compounds that are the color you describe are copper, but it's a strong possibility.

I think I would contact Rotometals and see what they have to say.

[KingBee]

Thanks Paul, That's a good idea. I've just sent them an e mail.

[Paul5388]

Suppliers for the handloading community tend to be easy to get along with and they will usually bend over backwards to help when and where they can. We just tend to think of them like normal commercial outlets that will try their best to keep from doing what's right. Either that, or we just never get around to asking them.

If your email doesn't get any action, give them a call and talk to them about the situation.

[Calaveras Slim]

did you flux and skim the top of your melt before you started casting?

[KingBee]

I fluxed and skimmed several times. The dross just keeps floating up. It appears that this stuff is just really cruddy. I was expecting nice, clean, ready to cast metal, so I was a bit suprised when I got all this crud. I've never bought lead before, always having used scrap. It looks like I will have to keep fluxing until I can use the stuff.