Removing tin with continuous re-casting

[Bob58]

I have been casting several times, using the same 2% tin - 5% antimony - 93% lead alloy each time. Since the bullets aren’t turning out with the quality that I want yet (but I’m seeing improvements each time I cast), I just place the previously cast bullets back into the pot for the next session.

I am fluxing with cedar mulch, that I originally purchased for pet bedding. This seems to work pretty well - at least, I’m getting dross from the fluxing, and the surface of the molten metal is bright and shiny after fluxing.

My question is, since this is a pretty low percentage of tin to begin with, am I likely to be losing enough tin during this "cast - remelt - recast" process that I should add some tin to the alloy? I’ve wondered if part of the reason for the incomplete bullet fillout that I am still occasionally seeing is due to the tin content being too low. Opinions?

Thanks,

Bob58

[Bass Ackward]

Bob,

The answer is could be, and probably not. Tin will burn out and the rate of burn out really increases above 800 degrees. But if you already have tin in it, adding more does nothing to lowering the melt temp.

Bullet fill out is strictly a temperature related event or a cavity contamination situation. You need "about" 200 degrees above the temperature where your mix begins to liquefy in order to give your molds enough time to vent properly and allow good fill out.

If you don't have a thermometer though, that information is worthless. And that is why adding tin is a safe option as it lowers the melting point and begins the 200 degrees from a lower point.

The fastest way to clean out a cavity is to heat up the mold and then open it and spray the cavity with a degreasing cleaner like Gun Scrubber or something. Keep it away from open flame. With the pores of the metal open, it cleans quick and easy. Never found a new mold yet that wouldn't clean up this way. beats soaking and scrubbing. I do this especially when I over lubricate my pins and get it in the cavities. 30 seconds and I am back throwing perfect slugs. Make sure you allow all moisture to evaporate before you continue.

[montana_charlie]

Sure hope your base metal is conditioned...
CM