HuntingNet.com Forums - Birchwood/Casey perma blue

Quote:

ORIGINAL: Charley

Oxpho-blue is a cold blue, of course. Is is a surface coating, like other cold blues. Blue Wonder is entirly different, I believe it is a photo chemical reaction to a micronized metal coating that does penetrate ferrous metals. Doesn't rub off, like cold blues, and does provide a very good degree of corrosion protection. Corrosion protection is higher than hot blueing, because the finish is not a layer of oxidized metal.

Well birchwood/casey perma blue from what I understood when i read about it, thats what it does too. if you ever looked at the perma blue its clear in color, and blackens or blues the steel on contact its deffinately some sort of a physical reaction with the steel. I tryed rubbing it off, the new blueing doesnt rub off. Its deffinately not just a coating like somany other cold blueing products. also its directions specifically state it will NOT blue non-ferrous metal surfaces.