Question on cases before loading

[MrChris]

So I picked up some cases and started cleaning them. I am running an ultrasonic cleaner. 2l water and 1 tbsp dawn 1 tsp lemishine.
Works great, however about 5% of the cases are coming out with a rose / rust color to them on the inside and out.
What is causing this, and are they safe to load?

 

[rswink]

Too much Lemishine for too long

Sent from my Pixel 4 using Tapatalk

 

[MrChris]

Too much Lemishine for too long

Sent from my Pixel 4 using Tapatalk

I was wondering about that. Is 1 tsp too much for two 480 sec cycles?

 

[BReeves]

Sounds like your cleaning process is leaching the tin part out of the brass and leaving the copper. Just a guess.

 

[OKCHunter]

Yep. I’m guessing too much Lemi Shine. I use stainless steel pin tumbling and my mix is 1 gal of water, 1 tablespoon of dawn, and 1/4 teaspoon of Lemi Shine. You can Google effects of Lemi Shine on brass.

 

[MrChris]

Thanks guys. Back to the drawing board

 

[thor447]

Pulled from another website, but good info:

Acidic water dissolves the tarnish. The tarnish is nothing more than metal oxides. This is how acids dissolve metal. There must be an oxidating agent to oxidize the surface of the metal (or simply regular water and air and a lot of time), and the acid then dissolves the oxidized surface layer, exposing fresh metal to continue the cycle. In the case of tumbling brass, you are just removing the oxide layer with acid, and no oxidizing agent. (If you put lemishine and hydrogen peroxide in your tumbler, you could dissolve your cases away!)

The "polish" or smoothness of the finish will be the same in either case. The color is different, because tarnish is darker.

 

[swampratt]

You guys are using a lot more dawn and lemishine than I do.
I use 2 quarts of water, 1/8 teaspoon of dawn and 1/8 teaspoon of lemishine.

I Now use Armor All Ultra shine wash and wax instead of dawn.

 

[MR.T.]

I don't even use dawn,
Just a couple pinches of lemishine measured with my thumb & finger.
& when rinsing everything out after cleaning I'll use some liquid car wax in the water & shake it around a bit.
This seems to be working for me.

 

[Fyrtwuck]

I use the Frankford Armory tumbler with no pins. Hot water with one squirt of Dawn and a 9mm case full of lemishine. After a few hours, I dump the dirty water, rinse with hot water, shake all the excess water off and throw them in the media tumbler for a few hours. They come out dry with that little bit of lubricity to go through the dies without sticking.