Project of the day: Home made hot bluing tank from scrap metal

[destrux]

Needed a tank to hot blue my KP31 Suomi build (I'll post that in another thread). Rather than spend $50 on a steel tank that was bigger than I needed I grabbed an old computer case made of steel and about an hour with the sheet metal brake and welder and I have this tank that will sit nicely on a two burner hot plate or a camp stove.

http://i1094.photobucket.com/albums/i458/destruxxx/20140114_213756.jpg

Just to be sure it had no plating on the metal I filled it up with a 5% CLR/water mix and let the acid clean the steel for a half hour. Then I rinsed it very well in anticipation of filling it with caustic soda and sodium nitrate bluing salt mixture tomorrow night when I blue my barrel jacket and receiver.

[TheGrimReaper]

Lets us know how she turns out!

[FrankG]

Very cool ! Im a big fan of repurposing materials ! Where did you find the 'salts' materials ? All stores used to carry Red Devil Lye but took it off the shelves !

[oldred]

Very cool ! Im a big fan of repurposing materials ! Where did you find the 'salts' materials ? All stores used to carry Red Devil Lye but took it off the shelves !


Try "Drain-Out Crystals" from Walmart, I have used this stuff and the results seem to be as good as the commercial bluing salts I got from Brownell.



WARNING!!!!!

You can hurt yourself seriously with any bluing salts so read up on the "how to" before attempting this, there's a darn good reason hot bluing is not usually done at home, you can certainly do it but it's definitely not something to learn about through trial and error!

[tomme boy]

The tank should be made out of stainless steel.

[Reg]

No reason what ever that tank will not work as good as anything as long as it is plating or finish of any kind clear on the inside. Actually smaller tanks make a lot of sense as there is really little need to fire up full size tanks when all you want to blue is a pistol or a few small parts.

You might want to make the top a little more even and uniform though. Even though there seems to be no way to stop the "creep" of the salts it is good to have some kind of lid on it.

[evans]

The tank should be made out of stainless steel.

For parkerizing yes but for hot salt bluing you want a steel tank.

[destrux]

I did strip the plating in the tank using phosphoric acid before I used it. The acid took it right to bare steel after a 20 minute soak. No problems with using the steel tank. It actually blued as nicely as the gun did.

I used Drain Out crystals, 7 cans per gallon of water. Supposedly it should have the proper mixture of caustic soda and sodium nitrate but I think it was lacking in the caustic soda a bit. I was only getting a boiling point of 240 degrees rather than 290 as I desired. I had to cook it longer to achieve the results I wanted, ended up stopping at 45 minutes.

I need to get better pictures out in the sun, but the job turned out very well. The only flaw I had was where there was a joint in the trunnion. The joining of the parts by the factory was so fine that I was unaware of there being a joint there, and despite sweating the parts thoroughly in degreaser some oil still seeped out and left a spot that did not blue. I degreased it again and touched it up with oxpho-blue and I'm satisfied with that.

http://i1094.photobucket.com/albums/i458/destruxxx/20140115_211305.jpg

[rcmsr.1]

Can I build a gun blurring tank out of a hot water heater

[DCM]

That looks very good Destrux.

[oldred]

DRAIN OUT CRYSTALS ARE NO LONGER AVAILABLE!!!!

Not long ago I tried to buy some at WalMart and they were out of stock so I asked when they would have them in, when I told them I needed at least 6 bottles I got some odd stares and told in unfriendly terms they would not be re-stocking that product. Seems those damn meth-heads used that stuff for some purpose and it has, unfortunately for us, been taken off the market! There are a few (very few) internet sites that still have some left but you will pay dearly for it and when shipping is factored in (and in some cases even before shipping) the price is higher than just buying regular bluing salts from Brownells. This was a good trick that worked quite well but no more!!!! :evil: