What about Cold Galvanize spray paint? That has some zinc in it.
we use it here and there at the marina for different things.... it seems to more about "rust prevention", as opposed to etching... I think it would be ok to do parts with, but I wouldn't use it on a sheetmetal app...



I actually got it to roll most of the time by making the chains sooper tight, than jumping on the raised end of the stand... it could be corrected by redoing the mount plates, but I don't plan on doing it again in my lifetime.. 
