How do I clean a used iron mold?

[kingstrider]

I happened across a pair of used iron molds for cheap but they have lead smears under the sprue cutter and along the block faces. In addition it looks like one of them has something on the pin or in the alignment hole which keeps it from fully closing. How do I clean these things up and get them ready to use again?

[Calamity Jake]

A pencil eraser will remove alot of it. You can also take the spru plate off, clamp it in a vise then heat it to lead melting point with a torch then quickly wipe the melted lead off with a wet rag, should work for the mould too just keep the halves together.

Look closely at the pin/hole for trash dings or burrs. Dings and burrs can be removed VERY carefully with small files or fine sand paper.

[HeavyMetal]

As for the lead smears I'll suggest "warming" the mold and, using a very light touch, push a single edged razor blade across any smears. If they present a raised edge this will take it off. Some discoloring will alway exist in on the sprue plate.

I have stripped sprue plate of the mold heated them with a porpane tourch then applied "sprue plate lube" and then allowed them to cool before putting them back on the mold this has done wonders in preventing future smearing.

Alignment holes: get an Exacto knife and a dental pick and have at it. A neat tip here is the canned "Air" that the computer warehouses sell to blow off your key board and such make a great forced air supply for doing odd jobs like this if you don't have a compressor!

[mooman76]

I heat my moulds or rather when I am finishing up and the moulds are still hot, brush the mould off lightly with a small brass wire brush where the lead smears are.

[10-x]

1+ for the razor/exacto and brass brush, been doing that for years.:castmine:

[John Boy]

Eezox ... http://www.eezox.com/
Cleans out leading in bores too

[cuzinbruce]

For the smears, try rubbing them with a piece of lead, a bullet or an ingot, cold. Or try BRONZE wool. Neither can hurt the blocks.
When you cast with them, a tiny bit of bullet lube where the lead is smearing or sticking can sometimes eliminate the problem. Put it on with a Q-Tip (cotton, not polyester).
To clear any burrs on the locating hole for the pin, I have taken a drill bit that fits the hole and put it thru so that the side flutes were bearing on the hole. Then just turn it with finger pressure. It is not chucked or anything, just held in your finges.

[kingstrider]

Hey thanks for all the tips. I should have mentioned that one of the molds also has lead in the cavity itself and I'm hesitant to have at it. Will heating the blocks warp them if they are not clamped together?

[Wayne Smith]

Preheat the blocks, pour in molten lead and by the third boolit the lead in the mold will be gone. Don't bother heating the blocks separately.

[Marlin Junky]

This is an easy one. Soak the mold halves in Hoppes #9 for about a week.

MJ

[DLCTEX]

I clean mold blocks by dipping the lower front corners into the melt until the mold is very hot and wipe off any lead with the palm or finger of heavy leather gloves (be quick, don't linger). Corners are cleaned with a light touch of a knife. I do not like to use boolit lube for lubing molds as it forms a hard carbon deposit after a while that is almost impossible to remove. I prefer to use Bullplate lube from our own Bullshop (bottom of page) as it works better, lasts longer, and no carbon buildup. Just my dos centavos. DALE

[Typecaster]

Hey Dale—

I think we could call your technique "finger-lingering good."

Richard