So what happened to my nickel plated brass?

Yesterday, I tumbled 200 pcs 38 Spl (all Starline), and they came out sightly tarnished looking and kind of dull. Same process as always.

Today, I tumbled about 150 pcs of 10mm (a few were nickel), and they came out bright n shiny. Same process as always.

Go figure. I'm seeing no rhyme or reason to this.
 
But I'm using the same pins every day, and getting different results.

In fact, since my last post, I tumbled some 45 ACP and they came out brilliant bright.

That said, there would be no harm in cleaning the pins by themselves. Next time I need to tumble, I'll run the pins by themselves first, then tumble the brass.
 
After every batch I rinse out my SS pins and tumbler. I've found if I don't my results get progressively worse or less shiny.
 
I've had nickel wear off cases just from resizing, long before the stainless pins.

Nick,

A couple of things come to mind: One has been covered: The pins need to be tumbled by themselves for awhile when new, not only to remove lube used to help the process of cutting them, but to dull the edges at their ends where they were cut.

The main issue seems likely to be a galvanic reaction of some kind. That could happen in either acid or base solutions, just as you can make either acid or alkaline batteries. You probably aren't getting the exact same pH in your solutions every time unless you mix components carefully. There is probably an optimal pH range you can operate in and that you have to adjust the mix to achieve.

What you could try is a pH neutral cleaning solution. Citric acid is commonly used to adjust detergent pH in shampoos down from alkaline, and you could do that using one of the inexpensive plant pH meters from a big box garden center. Amazon has one for under $5. Just keep the electrodes clean with a non-metallic (don't want to contaminate the electrodes) cleaning pad, like a Scotch-Brite pad. These meters work by creating a battery by galvanic reaction between their two probe materials in an aqueous solution. They don't need batteries, for that reason. So if you neutralize the solution well enough that it doesn't show on the meter, I don't expect you have enough ionization to cause trouble for your nickel cases, either. You can, however, check the solution with the meter part way through the cleaning process just to be sure you aren't changing the pH by getting small amounts of metal into solution.

You could also just keep a record of pH readings for your solutions and note what they were when the solutions seemed to behave well, then aim adjustment at those numbers.

It is possible fine particles of brass are embedded in the drum surface that could react. You might try tumbling some water and vinegar with the pins for an hour or two to be sure to clear the surface off, then rinse the pins off and tumble the pins in water only for a while to clean them, too.

You could try using distilled water or RO DI water as a base mix, just in case traces of something in your tap water are contributing to the issue.
 
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Brass discoloration

U-Nick.... Just askin' now; But what effect would using something like OXY-CLEAN have on the brass/pins?
WILL
 
I've done 2 sets of pins now, & I always just run a good squirt of Dawn, & a teaspoon of granular Citric Acid ( my regular tumbling solution ) on new pins for a cycle or two of the timer, & rinse before I add brass... seems to work well for me...

NICK... I agree with the galvanic assessment... I may have to get a quick plant PH meter to test water...

speaking of water... I'm betting distilled water would be best to use ( in fact my new Frankford Arsenal tumbler recommends that in the instructions ) I just use soft tap water... however there are still many impurities, salt residue, minerals, etc. from soft water... plus water varies a lot with mineral content, & concentrations across the USA... betting the discolor of the nickel has as much to do with salt level, or mineral content of the water, aided by galvanic activity??? next tumble of nickel cases I might try with distilled water to see if there is a difference in the finished color of the nickel cases
 
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Dawn detergent contains 12-23% sodium sulfamate salts. Salts in and of themselves are not the issue.

I suspect that the sulfamates are a main part of the issue; see my previous post.
 
Oops. I never cleaned my pins prior to use.:rolleyes:

My first batch of brass was a mixture of brass and some nickel and they came out looking like brand new cases.

Can't remember specifics but I read on some forums that you should only use the "blue" dawn because of the ingredients or lack of. Also I was told that many wet tumblers are switching to Armour All wash & Wax instead of Dawn because not only do the cases look better but are more resistant to tarnishing during storage.
 
The pins were pre-tumbled clean when new, before using.

I think part of what's happening is that my water here is hard. And its composition probably varies from day to day (it's municipal water - not from a well). I also think that when I haven't used the tumbler in a while, it seems the issue is worse.

My last three batches (chronicled in above posts) got progressively better as I tumbled them one batch right after the other. So there's something going on there. I checked the inside of the drum, and it seemed clean. I'm in a dry climate. The pins dry quickly because I'm the climate here is very dry; and also because of the wicking effect. Just sitting in the media separator, they dry in just a couple days. Right now, I have them in the sun - they'll be dry in a few hours.

Hard water.
Probably not getting the PH just right.
"Stale" pins / dirty tumbler.

I think I've got a combination of things going on.
 
My recipe is 2 Tbsp of dawn and 1/4 tsp of lemishine and I run them for four hours. Never had any cases brass or nickel plated not come out sparkling. Something is definitely going on there to cause that.

After a particularly dirty batch of military brass I rinsed my SS pins and then ran them for an hour with simple green in the water to clean the drum and pins and it was amazing to see the crud that came out from the pins.
 
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