Citric Acid experiment

[trevj]

Alright. I am a lazy Sonofagun. So when I read about the use of Citric Acid to clean brass, I figured I'd have to try it out.

For those that wish to do this on a very small scale, grab a half dozen pouches of unsweetened Kool-Aid, probably Lemonade flavor, and use that.

I used Citric Acid powder, from the local Brew Shop. Under $8 for a KG bag.
It is used for sterilizing bottles, works good to clean out the dishwasher, and you can make your own sour drinks with it if you feel the need.

Anyways....

The original state. Old, corroded, black and dirty. I started by washing the whole thing down with soap and water, to get rid of any grease on it.
The primer was loose, so I tightened it finger tight, and ran the hot water into it from the tap, as hot as it would go, to preheat the shell.

This is what the inside looked like.

I ran the shell full of hot water from the tap, added two heaping tablespoons of Citric Acid Powder to the water and stirred it. I then went a surfed CGN for a while. After 20 minutes, with one interim stir, this is what I got from the inside.

I then ran some hot water into a plastic bucket, added a couple more scoops of Acid powder (to the stuff I had dumped from the shell) and placed the shell into it. Only was able to get the shell part submerged in what I had, so rotated it around a few times over the next hour or so.

Heres what I got.
Inside.

Outside.

About three minutes effort with some polish and a paper towel, and I got a pretty good shine happening. The red color (copper, left on the surface by the acid eating away the corrosion) vanished really rapidly under the polishing cloth.

For the interested, the markings of the case.

I'm pretty happy with the results. I'll use this stuff again, if I have something that needs a good clean beyond simply firing it into a tumbler for a few hours.

Cheers
Trev

 

[SKS50]

Looks like it came out really nice there trevj,what are you going to tumble those cases in a cement mixer truck?

On another note next time you have a piece of tarnish brass put some Ketchup on it and let it set for about and hour before you wash it off with some hot water.

Another product that works really well and I have used it several time is Lemi-Shine http://www.envirocontech.com/products/Learn-More-about-Lemi-Shine.html I had a friend send me about 500 pieces of 9mm NATO brass that were covered with about 50% black tarnished. I mix about 3/4 of a cup of Lemi-Shine in a plastic coffee can in hot tap water throw the brass in and let it soak about 30 min. shake or stir the brass in the container vigorously several time before rinsing the brass with hot water and spreading the brass out to dry in the not sun or on low heat in the over.

The black tarnish will turn a very light pink color and after a couple hours in the tumbler will come out looking good as new. The good thing about the Lemi-Shine is it cleans out the inside of the cases also.

http://www.ar15.com/forums/topic.html?b=6&f=42&t=307848

 

[pilon]

That is one huge mother of a case!

 

[trevj]

Funny you should mention the cement mixer! I was just saying to a bud tonight that I was looking hard at mine as a power source to do a large batch of .223 brass.
I have about 2 gallons of them to do, once I get them de-primed. No tumbler yet. Figure if I steal the idea of the square bucket that was shown in the homebuilt tumbler thread, and mount it in the cement mixer....I don't have quite enough brass to justify the amount of walnut shell that I'd need, to just use the cement mixer. I have a Cement Mixer though!

The case is from a Austrian 15 cm WW 1 era field gun. Dunno how it came across the waters, but a friend gave it to me a few years back, when I was looking at it, at a gun show.

I have since used this same method to clean up some 22 brass that is destined to be swaged into .224 bullets. They were range pick-up stuff. They came nice and clean as well. Not quite as clean as they would if I used a ultrasonic, but pretty nice.


Cheers
Trev

 

[22to45]

Funny you should mention the cement mixer! I was just saying to a bud tonight that I was looking hard at mine as a power source to do a large batch of .223 brass.
I have about 2 gallons of them to do, once I get them de-primed. No tumbler yet. Figure if I steal the idea of the square bucket that was shown in the homebuilt tumbler thread, and mount it in the cement mixer....I don't have quite enough brass to justify the amount of walnut shell that I'd need, to just use the cement mixer. I have a Cement Mixer though!

The case is from a Austrian 15 cm WW 1 era field gun. Dunno how it came across the waters, but a friend gave it to me a few years back, when I was looking at it, at a gun show.

I have since used this same method to clean up some 22 brass that is destined to be swaged into .224 bullets. They were range pick-up stuff. They came nice and clean as well. Not quite as clean as they would if I used a ultrasonic, but pretty nice.


Cheers
Trev

Don't use rice as a tumbling media, It works like a charm on the outside with a little brasso, but packs like cement inside the cases.. I thought myself clever once and tried it, I had to drill through the rice to get it out of the cases.