I have an 89 T/A in very good condition and I'm always on the lookout for rust formation. I have some cold galvanizing zinc spray paint and I was wondering if spraying the underbody in key places would help slow the production of rust in those areas? Is anybody familiar with using zinc paint for this?

I have an undercoating on most of the underbody, can the zinc be sprayed right over that or must it be sprayed onto bare metal? How about onto metal that already has a layer of non-flakey rust? Removing the rust to bare metal is not an option.
Thanks.

 

Hey man,
I have used the cold galvanizing paint on many things before, and yes I do think it would help prevent rusting. How many chainlink fences do you see rusted out? I don't know how good it would do sticking to undercoating, but heck, why not try it. I would just put it where you think you need it, and see what it does...it won't hurt anything.

 

Zinc protects sacrificially. Meaning it gives itself up so the steel doesn't have to. The only way for this to happen is if the two, Zinc and steel, are in contact. By spraying over the undercoating the only thing you will accomplish is possibly creating a barrier just like the undercoating. The sacrificial protection works because the Zinc gives up electrons. So the Zinc actually has a "throwing power" allowing it to protect areas that are very close, even though they may not be covered (we're talking small distances and they must in electrically conductive contact). Just realize that the Zinc depletes itself, so although what I said is true, it is best to thoroughly coat the metal.

 

Thanks for the help guys. I was wondering about the paint needing to be in contact with the metal. I thought that maybe in the winter, with everything soaked with salt water, there might still be some useful electrical connection through the water. I agree that it won't hurt to try it. I might as well, I have 2 large spray cans of this paint.