Home Forums Reloading Bullet Casting Rust on molds

I have some unused molds that have surface rust on them
do I just oil it or use it as is?

Kroil and fine brass brush.

On the Cast Boolits web site, they have a number of methods for removing light rust from moulds.
Hope this helps.
I oil mine with KROIL (I don't suppose it matters what brand of oil, but KROIL in the cavities seems to improve casting.) and store them in a Cabela's dry box with a dessicant. So far so good.

Kroil is a great penetrating oil but it's poor for rust protection. As is WD-40, 3-n-1, etc. Ordinary Automatic Transmission Fluid is very good and quite inexpensive too.

Just got a mold the other day, and it had Molylube sprayed inside the cavity, and I thought, "Oh,Lord this is gonna be tough to clean" I decided to use it as it was, and just burn it out. The second bullet cast was perfect, no wrinkles and perfect base. I'm gonna buy me some Molylube! I know this doesnt have anything to do with rust, but wanted to pass on something you might like to know. I always like to get new tips!

get a lead pencil with an eraser.

color all the rusted mould with the lead, then erase it, taa daa rust gone.

I was given an old Ideal 311284 mold one time that looked to be hopelessly rusty. I figured I had nothing to lose so I bead blasted it. 30 years later it's still throwing beautiful bullets. I have used blammer's suggestion a few times with excellent results. Unlike most of you, it seems, I don't oil my molds except for seldom used ones going into long term storage. Those I slather up with RIG grease and wrap in waxed paper. A good scrubbing in acetone and then smoking the cavity with my lighter and I'm good to go.