Gunsmithing Hot Bluing Advice

Lucky Jack

Sergeant
Full Member
Minuteman
Aug 17, 2012
104
0
56
Southern AZ
I'm using Oxynate #7 bluing in a desert environment. I mixed up a batch of salt probably two months ago and blued some muzzle brakes. I put it away properly, covered the tank...Now the salts are deader than door nails. I know for a fact they were never even in the 300 degree range and there were no contaminants in the tank. I've tried to factor in evaporation but I don't think that explains it all the way. Any ideas?
 
Did you get a bunch of creep out of the tank? Do you filter your water? I usually throw in some new salt when I fire it up just for good measure since I don't blue that often.

I also started storing the salts in a plastic 5 Gal bucket. It eliminates creep if the bucket is new/slick inside.
 
When you say the salts are dead, what are you experiencing exactly? Is your solution boiling at too low of a temperature? Is it boiling at the proper temperature but your parts aren't changing colors? What's happening?
 
What seems like a hundred years ago, (really bad memory-issue here), my mentor told me something along the lines of "heat up the solution, throw in a few pieces of scrap steel, and a bit more potassium nitrate, to 'wake up' the salts."

You may have to dip the steel bits in, a few times to get things going again. This is after taking into consideration all of the points above. Proper storing and using (previous) applies, of course.

But yeah, I remember him talking about firing up the tanks after they had been sitting for some time. Having to bring them up to temp..... putting in some blued scrap-chunks of steel, and topping up the salts. Not much was needed in any case,,,, just some time and repetition to get things going again.

I'm sure someone with more detailed and more recent knowledge will verify, summarize, and clarify these thoughts.