I have some really old but strong casters which were once cleanly
galvanized but which have corroded through the zinc in many places.
They appear basically sound, though. I am contemplating heating a strong
solution of lye, then shutting off the heat (no open flame!) and putting
in the casters (sans wheel, of course) with the goal being to remove all
dirt, oil, grease, and, of course, zinc. Then I'd rinse in boiling water
after which they should self-dry quickly. Then I could brush off any rust
and prime the tops and then weld them to a plate, after which I'd paint
the plate and the casters all together, then reinstall the wheels.

I believe that the lye will dissolve the zinc, releasing hydrogen. I'd
do this outside, in free air, with no open flames nearby.

Anyone have any comments? Experience?

GWE