Can brass be damaged from over cleaning with stainless pins?

[Idgunner]

When the case mouth is 'peened' from extended tumbling the case mouth is rolled down on both the inside and outside of the mouth. You can feel a very slight ridge with your thumbnail. When a bullet is seated that extra ridge increases the mouth diameter enough to prevent the cartridge from chambering. All of those cases can be fixed by chamfering and deburring the mouth. Lesson is not to let the cases tumble too long.
After tumbling the cases in the media separator cage I submerge the cage in a water bath as I rotate it to help rinse the cases and flush out any leftover pins.
I always anneal my cases after tumbling even if most of them have only one firing. Does not hurt the cases and accuracy is maintained.

 

[7Footer]

I switched to SS tumbling a while ago because I am in the fortunate postition to have access to a lot of range brass, almost all of it .223, 9mm and .45. This stuff is often really rough stuff that's been in the snow and mud for a while, so I was looking for a cleaning sytem to clean them up before running them through my dies. Since this brass is pretty much free to me, I have experimented with different recipes and processes for the tumbler to see what works and also what can ruin brass.

First I have found that decapping first (I only decap the .223- I don't bother with the pistol cases,) while an extra step, this allows the water to fully drain from the inside of the cases. Once they are decapped, I tumble them for an hour to an hour and 1/2 using 1/4 cup of car wash soap and a teaspoon of Lemishine with 3 gallons of warm water and 15 lbs of SS media. This will clean about 1500 pieces of .223 or a whole bunch of 9mm. With this technique and recipe, I end up with batches of beautiful bright shiny brass with pristine primer pockets. Also, I think the carwash soap may have some wax or something that provides a bit of protection to the surface of the brass, because it seems to stay shiny longer.

When I have used dish soap or dishwasher detergent or Simple Green, I have issues with the brass turning pink or even red in color. The same thing happens when I use too much Lemishine, or go too long on time. If I just use dishsoap, the brass gets clean, but it never gets shiny and pretty. I have read that the chemicals in the detergents and Lemishine strip the zinc from the surface of the brass causing it to turn pink. I have also noticed that the pink brass quickly tarnishes to a nasty brown, espeacially if I don't do a great job drying them right away. I don't think that this has any real negative effect on the quality of the brass though, because I have been able to restore the brass color to pink brass by using walnut media in a vibratory cleaner. Since I just use this stuff for thinning out the prairie dogs or plinking with the kids, if I do end up with pink brass now, I just shoot it. As far as peening or flaring the case mouths, I clean the cases before I size them, then I trim them, so I haven't had any issues there.

So, to answer the original post question- In my experience with SS tumbling, I have tried to ruin brass, but so far, I haven't been able to do so.

 

[Moose Whacker]

Sounds like you are using stainless pins that are too large...get the ones that the jewelers use they are very fine and a little shorter. I have been using these for about 6 years now and no problems. Will never go back to dry media.

 

[marchboom]

After 47+ yrs of reloading, this is my method:

I start by depriming the brass. This allows the primer pocket to be cleaned and prevents air from being trapped in some cases thus preventing the liquid solution from cleaning the inside of the case.

Put the cases in an ultrasonic cleaner for 1 hr. Solution is 1/4 teaspoon of Lemishine to 1 pt of water. Hot water works better but is not necessary. Add 2-3 drops of Armor All Wash & Wax.

NOTE: Don't keep brass in solution more than 1 hr or increase the amount of Lemishine. Your brass will turn pink. The solution will contain the primer and carbon residue that would have contaminated your tumbler dry media. Therefore, your dry media will last a long time as it is only used for polishing and not cleaning. This method also keeps primer & carbon residue in a solution and not in a tumbler where it can become airborne.

Dry in a Lyman Cyclone brass dryer for about 1 hr.

Tumble for 60-90 minutes in walnut shell media (Zilla Ground English Walnut Shells Desert Blend from Amazon) with some Nu-Finish car polish. This media will not get stuck in flash holes. Throw in a used dryer sheet to keep down the dust.

 

[John Porter]

Never had a problem, never had to tumble more then 45nimutes. No detergent, just a pinch of citric acid which you can find in the cake decorating section of supermarkets. But you MUST have a media separator, a few turns each direction with the water nice and full and I have never had a rogue pin. Rinse thoroughly and if you want them to resist tarnishing just do a final rinse with some filtered water and bit of any "wash & wax" car polish.
PS. I do use an ultrasonic cleaner when I have just a few cases to do when doing load development, because it is very quick, providing you only have one layer across the bottom of the basket.

 

[crystalgayleguy]

just use brass juice in wet tumbler

 

[Roninco]

Brass discoloration can be caused by using too much citric acid. If using Lemi-shine only use
1/4 teaspoon per gallon of water or 1/8 teaspoon for 1/2 gallon. It takes very little to be effective. Once tumbling is complete remove and rinse as soon as possible.

 

[Dentite]

Been wet tumbling with SS pins for years and often 4 hours at a time and I have no problems. I have worked out a specific method and materials that work great for me. No damage to case mouths but I do run a quick inside chamfer before seating bullets.

 

[dartem]

If using the Frankford Armory Rotary Tumbler for the first time, clean just the pins alone and rinse very thoroughly. Never use more than a 9mm case full of Lemi-Shine and a squirt of car wash n wax with your cases. They will dry faster and more completely if you deprime beforehand...and it cleans the pockets and cases inside to look like brand new.