Grant Erwin wrote:
Up here in the soggy Pacific NW, we don't have to shovel snow very often
but we do have lots of problems with moss on our roofs. I was out
spraying Moss-Out on my roof just now, which takes awhile, and it got me
to wondering. That stuff is basically about as much zinc as they can
dissolve into water without including anything too dangerous. And of
course zinc in solution will reduce iron oxide to iron. So I'm thinking
if I had something small and precision that had rusted I'd try just
soaking the item in moss killer, might just make it shiny and clean ..
if so, that would be another trick.

Let's see, our bag of tricks include:

sandblasting
power wire brushing
pneumatic needle gun
naval jelly
vinegar and salt
various acid soaks followed by neutralizing basic soak followed by hot
water
electrolytic derusting
soaking in strong solution of molasses
soaking in solution of zinc in lye
and, maybe, soaking in moss killer

did I forget any?

Product called Evaporust.
Works like Electrolytic with no electricity, no mess.
Retail about $15 - $18/gallon if you can find it.
Reusable until you can't stand it.
Doesn't harm paint or plating, except really old, cheap paint.
Septic safe when done.

If you have something valuable or precision that is rusted, this is THE
best solution (no pun intended. really)
I have some machine jack spacers (I think that's what they are) that
will get dunked next time I'm at the shop.

No finacial interest, just a satisfied user who gave away my last sample
15 minutes ago and is trying to get my employer to stock it.

Rex B