I have a few razors in various stages of resto that have the original tang bluing: Case Red Imp wedge, Dubl Duck Dwarf, Challenger Razor. I've removed the pivot pin and separated the blade from the scales on the Challenger so far. I'm going to have to lose the bluing to clean the entire blade thoroughly before it goes in the tumbler with corn cob medium.

I've seen some attempts at re-bluing that seem decent but not uniformly dark (pics may not have done the work justice and I can't even remember when I saw such pics).

Is there a good way to be able to mask the areas of the blade that I DON'T want bluing on if I decide to re-blue the tang? I don't want the spine or the hollows blued and I don't want bluing to bleed into those areas. Any recommendations for ensuring a crisp clean edge between the blue steel and non-blued? BTW, I've never used bluing before but would research this on the net.

Thanks!

Chris L