Purple Brass!!!???

[Krav69]

Hey guys, I used some chemical treatment to clean my brass on the inside and outside, and per the instructions washed them off with clean water and dried them. The chemicals used were Lyman and Casey Birchwood's chemical treatments.

The primer pockets, which were filthy, came out clean, just like I was hoping.

Then I oven dried them, on the lowest setting, until fully dried.

And now, to my shock, I have purple colored brass. Not all pieces of brass are purple, but some are. I then tumbled the purple brass, but they are still purple.

What the hell!!???

Any ideas on what could have caused this? Is this a serious metallurgical problem? Is this a dangerous problem or merely annoying? Anyone else experience this?

 

[zuke]

Re: Purple Brass!!!???

Are you sure you didn't over heat them?

 

[Tripwire]

Re: Purple Brass!!!???

Doesn't anyone ever bother to own an air compressor and a blow gun to dry out wet cases?

Or just tip 'em upside down in the load block and walk away until tomorrow?

Put 'em in the damn oven, where do they teach this shit.........

 

[Krav69]

Re: Purple Brass!!!???

Tripwire--LOL!!!

To be fair, it is actually mentioned on the Casey Birchwood bottle, and this is my first time drying brass in the oven. Several websites related to the chemical treatment also mention drying the brass in the oven.

Next time I'll do it your way, for sure. I'm guessing you've never had purple brass!!!

 

[Gene Poole]

Re: Purple Brass!!!???

I use an ultrasonic with a little citric acid powder and detergent (check the Hornady One-Shot MSDS). I've gotten purplish tints before if I didn't rinse well. I've never tried the oven; just rinse with tap water and let them air dry in a loading block (neck down and leaning at an angle to vent/drain). Use distilled water for the rinse if you're anal about water spots, but they don't bother me and don't affect the case.

 

[The Mechanic]

Re: Purple Brass!!!???

Never seen that before but if it won't tumble out, I say toss them. There is no reason to risk safety and equipment over a few bucks worth of brass

 

[High Binder]

Re: Purple Brass!!!???

Seems like I type this up at least once a week and for years now but here it is again and before I hear the same old shit let me preface this by saying I'm a mechanical engineer who worked as a machinist and has many metallurgy classes under my belt as my specialty as well as my profession is as a tribologist.

OK, that being said oven drying is OK. B7 doesn't start to anneal until ~400F and even then it takes days, far longer than to simply dry the brass. Oven drying at it's lowest temp ~170F will have ZERO effect in terms of annealing no matter how long it stays at that temp. The purple/blue colors you're seeing is oxidation and is perfectly safe, if you want to minimize this do a final rinse in a low concentration baking soda in water before you dry. My favorite method (I've tried them all) of drying brass is with 90% rubbing alcohol in a bowl, drop all of my freshly wet brass into the bowl, toss to cover and then strain the brass out and put brass on a towel. The alc is reusable and the brass is dried with no/little oxidation within 30 or so mins.

 

[BuzzBoss915]

Re: Purple Brass!!!???

Yeah, I wouldn't be so quick to toss my fireformed cases because of a purple tint. With the work I put into prepping my cases, it sure as hell ain't, "a few buck worth of brass". But, who ya gonna believe? Some free advice is worth what you pay for it. BB

 

[Tripwire]

Re: Purple Brass!!!???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: High Binder</div><div class="ubbcode-body">Seems like I type this up at least once a week and for years now but here it is again and before I hear the same old shit let me preface this by saying I'm a mechanical engineer who worked as a machinist and has many metallurgy classes under my belt as my specialty as well as my profession is as a tribologist.

OK, that being said oven drying is OK. B7 doesn't start to anneal until ~400F and even then it takes days, far longer than to simply dry the brass. Oven drying at it's lowest temp ~170F will have ZERO effect in terms of annealing no matter how long it stays at that temp. The purple/blue colors you're seeing is oxidation and is perfectly safe, if you want to minimize this do a final rinse in a low concentration baking soda in water before you dry. My favorite method (I've tried them all) of drying brass is with 90% rubbing alcohol in a bowl, drop all of my freshly wet brass into the bowl, toss to cover and then strain the brass out and put brass on a towel. The alc is reusable and the brass is dried with no/little oxidation within 30 or so mins. </div></div>

I concure, and won't argue with metalurgy....but all that sounds like way more trouble to get cases clean than just tumbling in treated corn cob and being done with it. The only time I have wet cases is when I anneal, and that's just a matter of turning them upside down in a loading block until the next day. If I'm in a hurry I blow 'em out with the compressor. I think people take this case cleaning thing WAY over the top, but that's just me.

 

[Skid1]

Re: Purple Brass!!!???

I don't know, but I would think from a marketing stand point, if they were still structurally sound, colored brass might be a hit with some of the younger shooters.

 

[223ai]

Re: Purple Brass!!!???

Nothing wrong with putting them in the oven. I FL size/deprime, SS tumble, and then drop them on a cookie sheet at the lowest setting in the oven for an hour. I've 8 loads on my 308 brass with no ill effects.

 

[Chiller]

Re: Purple Brass!!!???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: The Mechanic</div><div class="ubbcode-body">Never seen that before but if it won't tumble out, I say toss them. There is no reason to risk safety and equipment over a few bucks worth of brass </div></div>

Agree. One place where you dont want to find out if you have affected the metal......

 

[Chiller]

Re: Purple Brass!!!???

Can I also recommend you look into the SS method of cleaning.....