doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Rust Bluing Mysteries

While bluing a set of shotgun barrels I experienced a problem that I have never seen. I got around it but Im not sure why it worked. I thought maybe someone here could shed some light on the subject.

My typical procedure after boiling the barrels is to blow the excess water off with compressed air, then card. On these barrels the excess water around the rib area destroyed the bluing underneath the black oxide. When I carded you could see where every drip of water had run.

My first thought was grease or oil. I started over about 6 times, degreasing, then back into the sandblasting cabinet. Nothing worked. I decided at that point to skip drying off the barrels after boiling and go straight to carding. It worked. Once I had the oxide carded off the barrels if any water got on the metal it did not cause a problem. That is what I do NOT understand. I followed the same procedure for the rest of the job and it turned out fine. Anyone here ever seen this?

If you used an air compressor it is possible there was contamination in the tank or hose. The streaking from the contaminated compressed air may have caused the problem.

Jim

Hi Bill:

If your are using a piston stype of air compressor, I would bet that this is your problem. The air compressor is a great source for oil and moisture laden air. I have learned this the hard way!

I think that you answered your own question if you did not use a compresser to blow your your work dry.

Just a guess though,

Franchi

I believe your air is contaminated as the others have pointed out. An in line dryer will fix that, any automotive paint supply has them. I use the throwaway hose mounted type when I need one.

I'm not sure why you would need a compressor. Don't the barrels dry nearly instantly when you pull them from the boil?

What little water I might find pooled in a dovetail or something like that I wipe down with a paper towel soaked in alcohol. I do that only to prevent any mineral deposit as the water dries (which it would in about 20-30 seconds if not less).

Brent

Use distilled water when boiling the bbls. An yes use a dryer on the compresser or used canned air,like you buy at a electronics store.

John

I use distilled water. My air compressor is oil less but that doesnt mean there isnt something still in the lines. Good idea on the filter.

Bill:

I too think it important to get the water off the barrel quickly. Howsomever, now that it is out in the light of day, I haven't a clue why I think so. No matter. It makes me feel good about myself...

I have a heavy terry cloth robe, rejected by spousal unit, spread out on the bench in front of the boiling tank. The work comes out of the tank and onto the terry cloth and the cloth folded over and like magic the barrel is dry.

Glenn

Bill,
If you elect to put a filter inline, a couple of things I learned while painting a car. One was that you can attach an auto oil filter bracket on the wall and put a new oil filter on it. This works wonders in controlling moisture output from the compressor tank. Then there's a little filter made to screw onto a paintgun between it and the hose, that will also fit between a air nozzle and the hose. Those two things will assure no debris or moisture/contaminants.

Was this a double gun?
Your using a sand blaster to remove the bluing?
Might be that you have a small pin hole in the rib(hope you don't have water under the rib) and water has leaked. This will destroy any finish if you don't get a good seal rib to barrel.