Lyman 4 cavity with surface rust

[Swede44mag]

What is the best way to clean a Lyman 4 cavity 148gr WC with surface rust?
No pits that I can see.

I have has it in the upper cabinet for years when I started looking at the molds I have I discovered it was rusty.

[NHlever]

Mine have cleaned up well using Kroil, or mineral spirits, and 0000 steel wool. The fine steel wool will remove the rust but not damage the mold. I've used the same thing on mildly rusted used guns I've picked up since it won't harm the blueing.

[HeavyMetal]

Try a product called evap-o-rust.

Couple members here tried it and were impressed ith the results so I went to Harbor Freight and got a quart, 9.99 and tried it out.

I had a 4 cav wad cutter mold that had some speckling all over it.

30 minutes in, rinse in hot water, Q-tip coated in Kroil and "SAHZAM" perfect cavities!

[shotman]

toilet bowl cleaner dont leave it set for long time about hr and clean with a old tooth brush. and repeat if need to. MAKE sure you oil well for a day then clean oil off .

[BCall]

Evap-o-rust works great. Doesn't take long at all, and you can re-use it. Just pour it back in the bottle till you need it again. I've rescued a number of old molds this way. As long as it wasn't pitted too bad, they have all became nice casting molds.

[NewGuy]

3rd vote for EvapoRust. Works great!