Recoating Molds

[LEADHOPPER]

Alright guys, I had some RCBS molds that had a little bit of surface rust. So I soaked them in a solution to remove rust from steel. And remove rust it did. My molds are cleaner then I have ever seen. Problem is that I did not think that the black oxide coating is in fact oxidation and that the solution that I soaked them in removes oxidation. And you guessed it, it removed the black oxide coating along with the rust. Is there anything that I can recoat these molds and sprue plates with. I thought about hot blue, as I just read the post about hot blueing with drain cleaner. I also thought about seeing how much it would cost to have it sent to the process house up the road from the machine shop that I work at. Any suggestions would be appriecated.

LH

[462]

Lyman moulds will self-blue with use. In fact, to finish their moulds, Lyman uses a heat treatment process. I Oxpho-Blued a Lyman, once...might try it on your RCBS moulds.

[Wayne Smith]

Just use them. The heat will re-blue them. Not a problem. You may have to be a little more aware ofrust in the future, though.

[MGySgt]

Just use them - when done casting and they have cooled - spray them with Pledge (yest the furniture spray, whipe them off. They won't rust and you don't have to clean them before the next use. one or two fills and your boolits will come out fine.

No more rusting either.

[bhn22]

WD40 on a hot mould (outdoors) will do a pretty job of bluing a mould.

[cephas53]

Did the same thing a couple of weeks ago. Cleaned a lyman mold I was having no luck with at all in a citric acid solution. Got distracted and was several hours until I remembered it. Came out looking like an aluminum mold. Thought I'd screwed up but it cast great now. Sprayed it down with some oil and bagged it. Seems to be getting a little color to it.

[theperfessor]

I've made some aluminum molds with steel (4140) alignment pins pressed into them. After an hour or so of use the turn a nice dark blue color. I would bet a few casting sessions with your molds will cause the same thing to happen. But I could be wrong. If you're really that concerned why not just use a little cold blue?

I also use a blackening compound (I'll have to check on name when I can get into shop later) to blacken tooling and fixturing that will not go through heating/cooling cycle to give some rust resistance, it works good for that.

[canyon-ghost]

Mine seem to stay fairly rust-free just from using parafiin was to flux. Might heat it up and run some candle wax over it.
Ron

[geargnasher]

They will reblue in one or two sessions, but where you apply lubricant it might take longer or discolor.

Most of my steel/iron moulds have been brown/blue when cleaned up for the first casting session, but after casting they were almost iridescent (sp) blue/black like grackle feathers. Cavities that have been lapped to white metal will reblue in the first session.

Gear