I am new to casting bullets. I was given about 10 lbs of greasy wheel weights and decided to fire-up my lead furnace and burn the oily junk off and cast them into ingots for later use. The pot got hotter than I expected––900 degrees F according to to my RCBS thermometer. I wasn't casting bullets––just ingots. Does this type of a high temp that made the wheel weight alloy bubble have a negative effect on the alloy?
There was a great deal of dross––grey, crusty material that looked almost like charcoal & bricket ash. I've read that this may be antimony, so I fluxed with Frankfort Arsenal smoke free flux (boric acid, I think...) but it wouldn't go back into solution, so I skimmed it off.
While fluxing, I noticed a rust-like residue on my mixing spoon––there was a thin layer of motlen lead, then when I tapped the spoon to get the lead off, the brand-new spoon looked like there was an additional layer of rust-like material.
So––are hese are all normal things to experience when melting wheel weights? When all was done I have 8 ingots––they are roughly one pound each––so I lost about 2 lbs as clips and junk––sound right?
Thanks for the help.
Sounds about right.
Try not to get your alloy so hot in the future. Lead starts off gassing between 800-900 degrees F. Unless you're wearing an OSHA approved respirator, lead vapors in the work area isn't something I want to deal with if I can avoid it.
Also, if you had any zinc weights mixed in, if you keep the lead around 600 degrees F, you won't have to worry about zinc contaminating your alloy.
I set up outside, Mother Nature provided a gentle breeze.
I certainly won't go that hot again. Thanks for the safety advice.
I actually got 8.5 lbs of material from 10lbs of wheel weights.
I've melted about 300 pounds of wheelweights so far, and have not experienced anything like you describe. I don't think 900 is high enough to separate out the antimony, but you shouldn't go over about 650-700 degrees.
Sort your wheelweights! Zinc weights, at least the ones I've run across, have "ZN" on them somewhere. I've gotten both stick on and clip on types. You do not want Zinc in your bullet alloy. Keeping your pot temperature in the recommended range will keep the zinc weights from melting...they'll just float on top like steel. Steel weights usually have "FE" on them, and I've gotten both stick ons and clip ons. If you get some lead stick on weights, they're nearly pure lead, so you might want to set them to the side.
Smaller weights give smaller overall yield. Large weights will give better yields. From what I've weighed so far, 80% yield is about right.
cast boolits website
ETA: Be absolutely certain that anything you put into molten lead is 100% free from moisture, otherwise you may have an "explosion" and end up with melted lead flying everywhere. Also, you might want to smelt the wheelweights in a different pot than the one you intend to use for casting. The less gunk you put in your casting pot the better.