Hello

I really have just started into melting bullets about two months ago. I just melted a bar of lead I got from the scrap yard it read "4 OATEY 1 Pure lead". When I melted it the colors it put out was amazing. I look like a gold and blue mix; all most like oil on water. I flux it and copper looking stuff came to the top. Took it off and more copper stuff came to the top. I reflux it four time and still the same amout of copper looking stuff came to the top. I decide to cut my losses and pure it into my muffin pan. Any ideas what happen. I took some pics of it will try to post it if I can get it to work.

How

I was curious what oatey was so I looked it up. They make/sell plumbing supplies, including solder. I can't help with the strange colors though.

I get a little of the colers you describe when casting with the wind blowing. I use a bottom pour Lee pot so I don't pay much attention to it. I suspect that your melt is to cold.
There are some "old hands" here that will explain this.
Cheezywan

Run your pot a little hotter. If it is a bottom poor pot I woldn't worry about it unless it's not making good bullets.

I run linotype, wheel weights, plumbers lead, basically anything I can get. As long as it's making shootable bullets.

Most of us get those colors at one time or another. When I'm making ingots I'll make up from 20 to a hundred pounds and skim off the top of the pot when I flux. Making big a batch at one time seems to make it easier with having good bullets thru out the casting session.

Actually there is no such thing as pure lead, excluding analytical grade metal, and actually not even then. It is just a lot closer and the percentages are accurately known.

What you are seeing are oxides of Silver which cannot be completely removed from Lead. In most alloys the Tin & Antimony tend to modify the oxidation and the colors aren't so vivid as with purer Lead. Don't worry about it, there isn't anything can be done and it causes no harm

I have always suspected that the Silver in Oregon trail bullets is nothing more than this irremoveable residual, since they don't seem willing to disclose Silver content. In truth all Lead alloy bullets contain some Silver.

More than likely what you have is casting solder intended for use on cast iron DWV pipes. Not a particular alloy mix of anything special and often consisted of all the stuff that was not usable for making drawn wire solder or the scraps from such operations. The coloring can be some Ag & As which tend to oxidize out making an oily looking film on top of the melt. It could also be oxides from residual fluxes used in acid core solder which will also produce similar skim films. It won't hurt a thing even if you're casting from a dipper because it'll generally wants to stay stuck together and holds itself away from the flow out of the dipper into the mold anyway. Even if a little gets into the mold, it'll ride the top of the melt right back out the sprue hole when the mold completely fills.

I've seen a gold coloring in pure lead before, but copper color is seen most often in babbitt metals. As long as it casts well, I would worry about it.

The coloring is oxides and their colors have some temperature dependence. There is good chance that if you alloy it with lead and antimony, you will lower the melting point enough that it all looks gray again.

Nick