Hi ODK Members,
Coming from an Electroplating background, What you have there is basically a caustic "Cleaner Bath" which in turn really needs to be heated just like a fish tank is but with a much bigger glass heater to a point where steam is coming from the surface. This process will also strip paint but Diecast metals should not be used as they have a Zinc content which caustic loves to eat. If used cold the process will slow right down and will take hours to perform opposed to minutes when hot.
As far as de-rusting is concerned the best method is to make up a Pickle Bath which again needs to be hot but requires no electricity at all as it is a "dip in solution only" type bath. Pickle baths are generally made up with 15% Sulfuric Acid and water but require the steel to be pickled to be totally oil free. This process is only good for Ferrous Metals and not "Die Cast" metals as they have a percentage of Zinc in them which sulfuric will attack instantly.
If you have any other electro/ chemical questions please feel free to ask as I'm only too happy to help out.
Cheers,
BB
