help for rusty molds, please.

[longcaribiner]

I was given a box of old molds that had been stored in a basement.  About a year ago, a pipe burst and things got wet and were never really cleaned up.  The Man of the house died years earlier and the widow gave me these last night.  There's Ideal, Lee, Lyman and RCBS molds.  I haven't sorted through all yet.  I sprayed them down with WD-40 for the time being.  Some have very little surface rust at the corners and some have started to pit on the exteriors and sprue cutters.  A few will need just wiping down.  Fortunately, he left a cast bullet in each cavity.  In order to prevent scoring the mold blocks, I think I'll have to remove and clean all the sprue cutters.   Some molds have lvery light rust in the cavities.  What is the best way to clean these up to working condition again?  (There's some really neat molds that I have never run across and aren't even in my old catelogues.  An Ideal 457401 wad cutter, a Lee 456 260 grain bullet, and some others, even a 4 cavity .439 Ideal mold, .43 Spanish I know)

[Bitterroot Bob]

Howdy,
It sounds like they weren't hurt too badly. I like to use Rem-oil as a rust preventive on my moulds. I wait for them to cool, then spray them and put them away. I would try spraying the affected parts and let them soak, and then try twisting a bronze bore brush in the cavity to loosen any rust inside.. Use a steel brush to clean the vent lines (your moulds might not have them) and to remove any surface rust. The oil will loosen any rust in the screw holes, too.
Lyman sells mould rebuild kits, with new screws and sprue-plates. As long as the cavities and mating surfaces are clean, the exterior doesn't matter. The fact that you can read the mould numbers is good news!
Take your time and let the oil do the work. As far as bullet quality goes, by the time you size and lube the slugs, a matte finish to the nose won't matter very much.
As for the #457401, that appears to be a 193-grain target bullet for the .455 Webley. Same for the Lee 456 mould. They could both be sized down for the .45 Colt, or used as a plinker/small game bullet in the .45-70, too. You are a lucky guy!

Bitterroot

[Graybeard]

Dunno where to get one exactly but a search on Google would likely turn them up. There is a tool similar to a sandblaster that uses baking soda as the abrasive. It's very mild. Back when I worked on electronics we used them to clean circuit boards. Get one of those and it will make them look again. I wish I had one for some old moulds of mine that got rusty many years ago in a similar environment to what you mention.

[WILDCATT]

I have left bullets in molds for years.if the blocks are closed air can hardly get in and the lead mix is stable.the iron molds I spray with WD40 on the outside.lee molds do not need any thing unless you store for years.

[Castaway]

For light rust, try a pencil eraser with a little oil and some elbow grease.

[Cat Whisperer]

One  classic rust removal is to use a fine steel wool with kerosene.  The kerosene lubricates and carries off the particles.  It usually leaves the bluing OK too.

[gypsyman]

Best stuff I've found for rusty molds, is a product from  Kano Laboratory's called Ex-Rust. Same company that makes Kroil. Follow the directions to a tee. Used it once on a piece of steel, and didn't coat it with a perservative when I was done, and I mean literally, within 10 minute's, you could see surface rust forming. Good stuff!!-gypsyman

[Lloyd Smale]

best thing ive found to do to cavitys that need cleaning up is take a bullet cast from it drill a hole in the base screw in a sheet metal screw cut the head off the screw and chuck the screw up in a drill. Put a little jb bore paste on the bullets and spin it slowly in the cavity. Ive done this also to molds that didnt drop real well. The outside can be cleaned up with a wire brush and reblued with some good cold blue.

[Doctor Sam]

There is an electrolysis method also.  12V battery charger, nail, baking soda solution, works great.