This is the first time I am having this problem. I am using my RCBS Sidewinder tumbler to clean my brass with the RCBS liquid cleaner.I did everything the same since I reload (25 years and more), but my nickel brass end up very stained (oxidized) almost black. This is the first time it happens. The only thing I might have done differently is adding a few standard brass case to be clean at the same time. Any idea.

Thank you

You have left your cases in the tumbler too long and the cleaner has stained them. You will find a warning about this on the instructions with your tumbler.

Nickel is super tough stuff. Might be some oxided brass residue sticking to them. Try to knock the surface stuff off with a rag and Brasso by hand, then, if it looks like they are coming back try some new, dry absorbant media in the tumbler for a spell and see if they get shiny again. After that dump that media as it's contatminated.

That lquid cleaner from RCBS must be brutal to kill nickel. Nickel's almost indestructible!

Tumbling media is a ridiculous price here in the UK, so I never dump it.
I put it in an old pillow slip & give it a full cycle in the clothes washer, followed by a tumble dry & a run over a fine sieve to remove any remaining dust.
Needless to say I'm single, so there are no screams about misusing appliances - same goes for baking paint & drying stuff in the oven.

Here is the website with the RCBS instructions;
www.rcbs.com/downloads...ctions.pdf

There can be only three reasons, contamination of the cleaner with something else; staining from the cleaner a/o heat; nickle coating wearing off the case.
The staining problem has happened to my friend who uses the sidewinder wet method and our solution was after inspection to tumble the cases in some walnut shell with some brasso or silvo polish.

guess I'm a guy that believes function trumps appearance. If the cases still function without issue, why bother other than to make sure it doesn't happen to the next batch.

English Mike wrote:

Tumbling media is a ridiculous price here in the UK, so I never dump it. I put it in an old pillow slip & give it a full cycle in the clothes washer, followed by a tumble dry & a run over a fine sieve to remove any remaining dust. Needless to say I'm single, so there are no screams about misusing appliances - same goes for baking paint & drying stuff in the oven.

It's not extremely expensive out here in Oz...but it's still pricey enough to warrant trying to clean it up a bit.

I have given the media a good spray with clean water and put a number (about 6 or 7) of "strips" of absorbent paper hand towel in with the moist media, turn it on, and let the vibes do their thing. The media comes out reasonably clean and the paper strips are filthy and have captured most, if not all of the dust etc in the tumbler.

Cheers, Vince

I thought tumbling media was what happened when reporters fell down a hill!!!

I've heard of putting used dryer sheets, torn into 1" wide strips, in the tumbler to collect dust and dirt.

Elvis, given the high regard most of us have for the news media I'm not sure those reporters just "fell"...

I've been using Nu-finish and finely ground corncob for years and have left the plated cases in the tumbler for days...Never heard of that problem.

Sounds like something reacted with the nickel plating.

I did a little research on nickle plateing and tarnishing of nickle. It seems that nickle turns black as does silver. This is from sulfur content in the parent metal and or environment; the reaction to acids both from other sources including air and is common. Nickle as it ages will have a golden colour rather than a silver colour when highly polished. I learnt something today. On closer inspection of my 9mm nickle finished cases, I can see a difinite difference in the different lot numbers of my reloaded cases.

For English Mike/Elvis/Vince: Call around to any of your local sand blasting companies and ask them if you can purchase a small amount of their corncob or nut shell media that they use for refinishing. I got my last batch from the local guys here and it was cheap. That and a can of brasso or silvo or powdered jewelers' rouge and away you go.

No Brasso...! And keep in mind that the Jewelers' rouge will also shine your resizing die.

Unfortunately I don't think there's a blast shop within 100 mikes of here.

Brasso contains ammonia & apparently can lead to neck splitting.

Bushmaster wrote:

No Brasso...! And keep in mind that the Jewelers' rouge will also shine your resizing die.

Good point about the brasso and I should have thought of that as we were told that brasso could be used to clean the barrels of our weapons in a pinch but that they needed hot water perferably to rinse off and then oil.
I have a couple of sticks of red jewelers rouge and one white and I would like to find out what type of lubricant they are using in the cloths and on the walnut media. I am thinking that it is a type of wax to make the rouge stick.

inthedark wrote:

You have left your cases in the tumbler too long and the cleaner has stained them. You will find a warning about this on the instructions with your tumbler.

For my RCBS Sidewinder it says, if I use the RCBS sidewinder liquid, to let it tumble at least 2 hours, so my problem does not come with the time I let it soak. I remember picking up some used brass at the range,maybe some were contaminated.