Weird color while annealing

[fatelvis]

You're looking at the result of a redox reaction on the surface of the brass, maybe a molecule or two thick. Zinc is not being leeched or smelted of the brass alloy to any significant depth. As an example, the "pink" color you observed after annealing can be generated in brass prep after brass prep by using too much Lemishine, low pH, or other chelating agents. It does not hurt anything other than the psyche of those that witness it. A single cleaning without excessive Lemishine/acidity/chelating agents is usually all it takes for the pink color to disappear. I understand that it is an unusual thing to see when it is first observed and that it may cause concern, but it's not a problem.

I like this answer the best. Just because it makes me feel like nothing is wrong. Just sayin! Lol

 

[Webster]

I like this answer the best. Just because it makes me feel like nothing is wrong. Just sayin! Lol

Sounds like a good answer. Still don't understand why it only occurs at that small area on the body on all of the cases. No pink on the shoulder? I would like to see a final conclusion after cleaning the cases and tumbling with less Lemon Shine then anneal. Why doesn't pink show after tumbling just after heat is applied. The OP needs to try different things and tell us the results.

Nice writeup on the problem. They blame the pink on LemiShine. I use LemiShine all the time an never saw pink? Quess it depends on how much LS you put in the solution? I use about a level tea spoon of LS in 1.5-2 quartrs of water.

Citric acid and brass

Brass is an alloy of metals primarily copper and zinc for the common brasses (roughly 70% copper 30% zinc. Using Citric acid on Brass dissolves a minute amount of the metal (don't worry it won't hurt it), but the dissolved copper can re deposit (the zinc doesn't) back onto the surface of the...

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[Ned Ludd]

I like this answer the best. Just because it makes me feel like nothing is wrong. Just sayin! Lol

I experienced the pink necks on many different brass preps over a period of several years before I realized that:

A) it was caused by my using too much Lemishine during cleaning

B) once I started using a more reasonable amount of Lemishine during cleaning, the color disappeared

C) the color didn't harm the brass in any way

Because of this experience, I looked into what might be the cause. As I stated previously, it's some kind of redox reaction limited to a few molecules deep on the surface of the brass. It occurs during the annealing process (i.e. while the neck is in the torch flame) and is potentiated by prior excessive exposure to chelating agents and/or acidity. Trust me, I know something about the chemistry involved and I didn't just pull this explanation out of my ass.

Like you, the pink color bothered me, even though I was certain after a period of time that it wasn't hurting anything. I mean, really, pink brass? Why not just stop at Target and pick up a case of Bud Light and some tuck-friendly panties, right? In any event, I cut down substantially on the amount of Lemishine I was using during cleaning (a little goes a long way), and the color disappear as expected. If the color still bothers you, I would suggest checking your cleaning process for the use of excessive Lemishine/lemon juice/etc., or anything that might be acidic or contain chelating agents. Be sure you are rinsing the brass well after the cleaning solution has been removed. I suspect you can probably find the culprit in your process, or at the very least prevent the color formation in future brass preps.