Black Oxide for Stainless

[asallwey]

Caswell offers a chemical, under their Black Oxide process, that works on stainless steel.

Has anyone tried it?
Do you use the BO sealer to finish it?
Is it a surface treatment or does it penetrate?
Does it hold up about as well as BO (which is fine)?

I'm thinking of using it on SS bolts and nuts for my old car.

Thanks!

Alex

[krymis]

i have used it many time and was happy with the results for the most part. The ss takes a special sealer. I also have found a few tricks to letting it take better. Etch your parts in a sulfuric acid bath. Let the parts sit after coating for about 3 hrs and place int he oven to cook and they will dry a lot faster. If you call greg at caswell's he will fill you in on all the tricks of the trade with this stuff. One thing I found was the part always seems to weep "always lets the sealer out" I have not found a way to stop this or have not been able to catch greg with my scheduel lately.

[asallwey]

Thanks for the info and tips. I think I'll get the kit and try to call them with a few other questions.

[asallwey]

Per their online support, it shouldn't hurt the nylon in nyloc nuts. Craig didn't know about the weeping, but suggested using Seal45. This appears to be a coating ideally used on porous items, and leaves a smooth coat. It probably wouldn't hold up to having a wrench tightening it, maybe a few times. I think I get blackener and play with it.