How to Clean Lead Residue from Mold?

[dbarnhart]

I have a brass mold. i noticed the other day that when I opened it many times the boolits didn't fall right out like normal. Today I examined it and can see a few specs of lead residue in the faces and a little at the bottom of one cavity. What is the best way to clean the lead residue out of a brass mold?

[Norbrat]

Get it hot, rub some candle wax on the lead, then rub with denim rag. Repeat if necessary.

Has usually worked for me.

I've also used a brass brush, the type for brushing suede shoes.

[mustanggt]

I use a carpenters pencil. Just run the graphite part over the offending specks and they are gone.

[geargnasher]

+1 on the pencil.

If you get the mould up to casting temperature sometimes it wipes off.

The best way I've found to prevent this is put the mould through several heat cycles of 400 degrees or so for a few minutes and let it cool. This will build up an oxide layer on the mould surfaces that's more resistant to stickage, and helps keep the cavities free of that tin "haze" that they get sometimes.

Boiling the blocks for ten minutes in a saucepan with distilled water, a few drops of liquid dish detergent, and about a two teaspoons of powdered citric acid or a splash of Lemi-shine (minus the detergent) will passivate the brass surface and accomplish the same thing.

Gear