[sgarnett]

A real "blued" finish on steel (actually closer to black) has been chemically etched and "oxidized" (don't know if's really oxide or some other compound) to form a protective surface layer.

I know the "cold blue" touch up finish sold at gun stores isn't the same process, and isn't as good, but is it still an oxide-layer type finish, or just paint/dye? Is it resistant to solvents? Does it provide any corrosion protection? Real blued steel will still corrode, but not as readily.

This post has been edited by sgarnett: Jul 13 2005, 03:24 PM

[trackbird]

I stand corrected.

The single largest drawback of cold bluing, however, is that it provides no rust protection. In fact, some blues may even promote rusting.

And from the same article and worth noting:

At the top end of the durability spectrum is one worthy of special note, Brownell's Oxpho-Blue. This stuff wears like chrome plating. You can scrub on it with fine steel wool until the cows come home and not harm the finish one bit. It does, however, have a rather strange appearance. It comes out sort of a metallic, charcoal gray that is very shiny. With many blues the slightest trace of oil is the kiss of death; however, another unique quality of Oxpho-Blue is that it actually goes on better if there is a little oil present during the application. In fact, the best way to apply Oxpho-Blue is with steel wool, which has a considerable amount of oil in it to prevent the fibers from rusting.

From here:

http://www.gunsandammomag.com/techside/blue_0515/