To all those that work with metal: I have some Hensley & Gibbs moulds that i bought that had been improperly stored in a storage locker and became a bit rusted. The blocks themselves and sprue plates have cleaned up rather well (they will never win any beauty contests, trust me) but the cavities have a fine coating of rust.
The cavities are not (apparently) too bad.
Before I start digging in to work them over, someone suggested I have the cavities bead blasted. I am not sure what they meant but whatever "blasting" gets done it cannot remove any metal, just the fine rust in the cavities.
Is there some way to do this without removing any metal in the cavities OTHER than by hand?
I have no objection to doing it by hand with Naval Jelly, steel wool and a pointed wood stylus, but if the bead blasting works, I'd save myself a ton of work.
ANY ADVICE?