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Post by erjdriver on Jul 24, 2014 19:29:30 GMT -5
Good evening all, I wet tumble with the Thumbler's Tumbler. My "formula" (along with the 5 lbs. of SS pins) is 1 Tbl. of Dawn Liquid and 1/4 Tsp. of LemiShine. I tumble for no less than 3 hours. Although most pieces come out clean on the inside, outside, and in the primer pocket, I saw this discoloration on some pieces out of the batch of .38 Special I just finished tumbling (a little out of focus):  Any ideas?? Thanks! |
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Post by springfieldxdm on Jul 24, 2014 20:08:08 GMT -5
I had a batch do a very similar thing. A chemical engineer friend of mine talked for about 20 minutes explaining how copper ions are removed from the suface exposing the zinc which is a different color. Essentially such a small amount is removed that as long as you don't feel it with your fingernail it was safe to shoot (or at least that's what I took from it). Next time you do that piece in the wet tumbler it will likely start turning pink in those areas. After about 4-5 cycles in the tumbler with lemon shine it will start etching and you can feel the roughness. That's when I scrap the piece of brass.
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Post by erjdriver on Jul 24, 2014 21:48:57 GMT -5
I had a batch do a very similar thing. A chemical engineer friend of mine talked for about 20 minutes explaining how copper ions are removed from the suface exposing the zinc which is a different color. Essentially such a small amount is removed that as long as you don't feel it with your fingernail it was safe to shoot (or at least that's what I took from it). Next time you do that piece in the wet tumbler it will likely start turning pink in those areas. After about 4-5 cycles in the tumbler with lemon shine it will start etching and you can feel the roughness. That's when I scrap the piece of brass. Cool. Thanks for the chemistry lesson!  So do you think this would NOT have happened if I just tumbled the brass in plain soap and water, skipping the LemiShine? Thanks for the response! |
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Post by springfieldxdm on Jul 25, 2014 15:11:15 GMT -5
Honestly have no idea. Just guessing, I would say no because there is not any acid present. Myself I don't sweat it as my brass is clean but not always pretty. When they get really pink it helps prevent other people from taking them at the range.
A lot of times if you toss the discolored cases in the vibratory tumbler with new finish and mineral spirits added to your walnut shells it will make them prettier.
Shelby
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Post by krwada on Jul 25, 2014 15:55:40 GMT -5
Lemishine is mildly acidic. The primary ingredient in Lemishine is citric acid, (lemon juice). Anyhow, the Chemical Engineer is correct. Tumbling for 3+ hours in a Lemishine solution will discolor the brass. I am not so sure about etching it however.
I do know that vinegar, (acetic acid), will etch the brass if left in solution for any (hours) length of time.
Citric acid based cleaners are commonly used to clean ferrous and non-ferrous metals. These solutions are very good at removing oxides, carbon and any kind of scaling. They especially work well in ultrasonic tanks with some application of heat. Of course, you need to use the stuff with some surfactant, (Dawn) added.
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Post by erjdriver on Jul 25, 2014 17:21:31 GMT -5
Thanks for the replies, y'all. I tumbled a couple more loads and used about half the LemiShine I was using...now 1/8 tsp. Things seemed to work and look better..... ETA:Well...I did my last batch of .38 Special and while it's not the shiniest.....came out somewhat dark after two runs through the tumbler.....it's dang clean.  |
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So do you think this would NOT have happened if I just tumbled the brass in plain soap and water, skipping the LemiShine?
My daughter came from Missouri, my son and grand son, my wife and I had a nice dinner of grilled "porter house" pork chops, corn on the cobb, my son, G'son and I share 10/5. G'son is 4 minutes early though @ 10/4.
Pooh I hope you find to right house . 
