I'll add a couple points to Jakes pictures - I've had quite a lot of stuff Redi-Stripped years past and have observed every part of the operation, asking as many questions as DennyG
I have some sheet metal on hand now that was done years ago and left sitting - the stuff stored indoors dry looks fine, the parts stored poorly have surface rust that hasn't changed in years .... I stopped using the Redi-Strip here [closed now anyway] when they quit using the phosphating step
the commercial operations use the phosphate bath
after the rust removal step - they keep the part wet for a specific time by immersing it in a bath - they
immediately pressure wash it with plain water when removed
Bill