Surface Rust Help Needed

[rbrandes]

Hello! New here - I have cast bullets before with borrowed molds.
Now I have this Lyman 35809 (150gr .38 wadcutter) from an estate sale that has surface rust all over.
I can deal with the rust on the outside surfaces, but need some advice for the bullet cavities themselves.
The mold was in a plastic Lyman box and was stored with bullets and sprue in place.
Still, the cavities show as much surface rust as the outside.
My first thoughts are to take the bullets and turn them in the mold with a fine abrasive like JB bore paste.
Any suggestions?

[MtGun44]

Start by scrubbing with Comet and a toothbrush. Be sure to use HOT water for a thorough
rinse, then fully dry and then oil the outside to keep it from rusting. If this does not remove
the rust, try a small brass brush and scrub the cavities thoroughly with RIG gun lube. It seems
to somehow help removing rust better than plain oil. Next try 0000 steel wool wrapped on an
old bore brush of the appropriate size and RIG, spin in cavities with a rod, or you may try
a drill, never did that myself, tho.

After that if it is still a mess, cast a boolit in it, put a screw into the boolit and lap the
cavity with JB bore paste.

Bill

[Bent Ramrod]

If it's just surface rust, with no heavy masses or pits, you may be able to just boil the mould in water for 20 minutes or so and wipe it off with a piece of fine steel wool. This treatment maintains the black finish that abrasives remove and I find I don't have to re break in the mould to get it to cast again.

If there are crusts of rust it sometimes takes a lot of repeat boiling to turn it all to black oxide, and sometimes no amount of boiling seems to finish the job. But for surface rust, boiling it is like one pass of slow rust bluing.

[rintinglen]

There is a product called Evaporust Rust remover, that is available at Lowes as well as many auto parts stores. Buy it, follow the directions and be amazed. Also, be ready to cast with the mold asap to get that heat bluing back on the mold to prevent further rusting. Mike S, a regular here, was the one who turned me onto it. I tried it on a mold in similar condition to yours that I bought at a gun show last spring and I was stunned at how well it worked.

[shotman4]

most times the light rust will come off in an over night soak in "Coke" that is the soft drink dont leave more than over night and wash well and oil for a day then clean to cast. OR best is Use Kroil

[bayjoe]

You might try an old trick trappers use on traps. Put oak or maple leaves in water, dump mold in water with leaves. Leave it there for a few days, the tanic acid in the leaves will remove the rust

[DLCTEX]

Use the same Lemishine solution, heated that is used for cleaning brass. Remove the black carbon with a brass brush. It will not remove any metal, just rust (iron oxide). Overnight or less will do it.

[HeavyMetal]

an old trick I've used is a simple lead pencil eraser! Used to be you could find type writer erasers but they went the way of the dinosaur years ago, they had a mild abrasive in them, but use the earser to rub the cavities and you'll find the rust will go away with a little work.

[runfiverun]

nobody mentioned that this is why we don't store molds with lead in them.
i'm sure a lot of this was because of not in spite of the lead in the cavity's.

[pahoghunter]

The best rust remover I ever used is BLUE WONDER, that and a toothbrush it works great.

[500MAG]

I use birchwood Casey blue & rust remover on surface rust with a toothbrush and it comes right off.

[captaint]

I used Naval Jelly on that exact mold. Cleaned up beautifully and cast great wadcutters now. Mike

[John Boy]

... a 50:50 mix of ATF and acetone. Scrub with brass brush. Put mold in ultra sonic cleaner to finish. Another method is electrolysis de-rusting

How do I know both of these methods work?
I just finished cleaning 115 molds that were under 36" of salt water from Super Storm Sandy. There were only 2 molds that I couldn't bring back to life - aluminum ones

[Echo]

+1 for Evaporust - I've rejuvenated a couple of molds with it - it works! I stuck the mold (handles attached) down into a jar with enough E. to cover, and left overnight. Out the next day, wipe with rough rag, and Press On!