Still having trouble casting roundballs from pure lead ??

[bchannell]

I'm getting a scummy dross on top, it starts forming as soon as I flux, and builds up fast. I get problems with fill out and sprues are cut funny, not round and nice.

1) What temps to you all normally cast pure lead at? I can't seem to get decent fill out until around 825F.

2) Is this a symptom of contamination? I've had the drossing problem for a while, but had always cast decent bullets anyway, it's just a pain and needs constant attention.

3) What should I use for flux? I've been using candle wax, and one time I tried a pine dowel. Would something else break surface tension better.

4) I ladle cast, would bottom pour help?

[Muddy Creek Sam]

Are you getting the mold hot?

Sam :D

[STP22]

When I cast with pure lead, part of the fluxing and skimming includes using my large spoon to scrape the walls of the pot and the bottom to free up as much dirt and debris as possible. Going as high as 852F* should not be necessary. You may have something else in your "lead" that is the cause of your troubles.

When you skim off the dross when you are at 825F*, do you see any particular color(s)? That may be a hint that you have something other than pure lead.

[bchannell]

The melt will turn purple as pure lead will when overheated. The dross is a gray scummy film, that just keeps forming.

I'm wondering about sprue plate venting, that the sprue plate might be too tight. Any thoughts on that? What is a good temp for pure lead?

[lwknight]

I would just add about 1% of tin to it. It will not harden the lead enough to hurt anything. At least test a small batch with a bit of added tin.

[bchannell]

Well, I added less than .5% Tin, cast at 730F and used a mold I know to be a good one and got about 80%+ good balls, so I'll continue to experiment. I just reworked the sprue plate on the .350 mold I was having trouble with and will try it now and see if it will throw a decent ball now.