Jump to content
SASS Wire Forum

"Pink" Brass Cases After Cleaning


Mountain Man Gramps

Recommended Posts

I made the mistake of leaving some brass cases in the tumbler overnight.  The tumbler had the Hornady Case Cleaner in it.   The next day some of the cases were lookin g bit pink.  I know that means some of the copper(?) was dissolved out of the cases.  Does this weaken the cases to the point of needing to discard them.

 

Link to comment
Share on other sites

Quote

Does this weaken the cases to the point of needing to discard them.  (?)

No.   If you don't SEE DAMAGE to the brass of the case, only a slight bit of copper and zinc dissolved.  Pitting of the brass case - toss it.

 

Case cleaners often have a weak acid (like sulfamic acid crystals) in them to loosen carbonate compounds off the brass.  LemiShine dish washer cleaner does too.  This  dissolves any copper and zinc carbonate off the brass (lots more off of black powder brass).    Through complicated electrolysis, the copper only plates back onto the brass.  The zinc (since brass is 30% zinc and 70% copper, more or less)  stays in solution, being less "noble" (yes, a real chemical term) than copper. 

 

If you want that copper wash to come off the brass, then use a little weak vinegar and a green scrubbie pad and scrub lightly.  It will mostly come off.

 

To prevent this from happening, don't leave brass in any cleaning solution more than about 5 minutes!

 

 good luck, GJ

Link to comment
Share on other sites

Also, if you're using an acid base cleaner, and any part of your brass has ferrous metal, steel, it will turn the brass pink.

Another reason to deprime your brass before cleaning.

As a side note, I do some silver work and, after soldering, I toss the piece into a pickle pot, which is an acidic fire scale cleaner. If there is ferrous metals in the pickle pot, which is highly discourage (including using steel tweezers to remove the piece) pinking occurs. Then it has to stay in the burnishing tumbler longer to remove the pink.

Link to comment
Share on other sites

I recommend keeping those "pink" cases seperate from your other brass.  They may be ok, they may not.  It will depend on how much copper was leached, they "could" become more brittle.  I had this very thing happen on a batch of brass and started to see close to a 20% case failure rate after that run.  That is way too high for me, so all that brass went into long term emergency storage.  Split cases are a headach and not worth te risk.  Not fun to have to bench about ten thousand pieces of brass when you could only bench the one batch to be safe and have piece of mind.

 

WK

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.