Rust removal for small parts, may one of those cheap rock tumblers? I was thinking of adding some sand and WD-40 or 3 and 1 and just lettingis run. Any thoughts?
I think I'd use EvapoRust before I tried tumbling them.
Evaporust will work, but it will take the blackening agent off parts. Charles Wood, from CMT trains (also made paint) told me to use fabric softener with sharp objects in the tumbler for nickle plated items. I use stainless sheet metal screws. Tumble, rinse with hot water (softener will be really dirty), then apply a rust preventative agent, lacquer, dip in WD-40 or Evaoprust. Been doing it this way for 25 years on prewar parts.
Hard to believe that sharp objects don't damage nickle plating, but if it works...