Weird color while annealing

[fatelvis]

I just came across these few pieces of Lapua brass that took on a strange color after annealing. They are from the same lot, and have been run the exact same way as all the others, yet they take on that strange copper color. Can anyone explain? Thanks.

 

[Webster]

I just came across these few pieces of Lapua brass that took on a strange color after annealing. They are from the same lot, and have been run the exact same way as all the others, yet they take on that strange copper color. Can anyone explain? Thanks.

Clean the necks with 0000 steel wool, it should go away. Could be from case lube. Let me know how it turns out.

ADDED LATER: The necks looks very dark compared to when I anneal with a torch for about 8 seconds.

 

[Bench shooter]

here is same question several yrs ago on here.

Pink color on freshly annealed brass

I just finished annealing some Lapua brass (6.5x47) and noted a pink color just below the shoulder where usually a light blue color appears. I also noted that as soon as I applied flame to the brass (within a second or two) a light green color appeared in the flame (zinc disintegration I...

forum.accurateshooter.com

 

[DLT]

Might be related. Might not but I have some new starline 223 brass that is that color on the inside of the cases

 

[fatelvis]

What puzzles me is, they are of the same lot, and treated exactly the same as all the others that do not show the pink color. I wonder what is the difference that causes this?

 

[Clancy]

@fatelvis which machine did you use?

 

[Kracken McGraw]

Might be related. Might not but I have some new starline 223 brass that is that color on the inside of the cases

This is what Starline says about the coating on the inside of the case necks.
Excuse my scribbling.

 

[David Milisock]

What puzzles me is, they are of the same lot, and treated exactly the same as all the others that do not show the pink color. I wonder what is the difference that causes this?

They were marked as the same lot. Who really knows?

 

[fatelvis]

@fatelvis which machine did you use?

I was using the Stainless Steel rotating table type, sold by a member on this website, I believe. It works beautifully, and it’s cheaper than most.

 

[fatelvis]

They were marked as the same lot. Who really knows?

I bought two 100 count Lapua blue plastic boxes and they were from the same lot also.

 

[mudduck]

I just came across these few pieces of Lapua brass that took on a strange color after annealing. They are from the same lot, and have been run the exact same way as all the others, yet they take on that strange copper color. Can anyone explain? Thanks.

I just had some br do the same when annealing. Two pcs from different lots

 

[William Vogel]

I can’t tell for sure about why the discoloration is occurring. I find it’s important to get the carbon off the necks before annealing. My cases form a really hard coating if I anneal before cleaning the carbon. I use steel wool to clean the cases first now. I’ve still got cases with the hardened formation even after 2 firings and clean/anneal. Luckily it’s on my starline brass for my stock gun vs the lapua brass for my “nice” rifle. It’s almost like an enamel coating. I’d say most likely it’s not from getting too hot. I know I run a few pieces twice in the process of getting my flame right but I’ve not had it do that before.

 

[Rocketvapor]

Could it be a chemical reaction between the brass and lube or cleaning media at high temperature?
Maybe steel wool off the color and anneal again to see if it comes back.

 

[David Milisock]

I bought two 100 count Lapua blue plastic boxes and they were from the same lot also.

My wife has me streaming down the conspiracy theory path.

 

[Coyotefurharvester]

Acetic acid will leach zink out of the surface of the brass, turning pink. The color change is often delayed, after washing.

 

[Dave M.]

Look up “dezincification while annealing brass”. The rose gold color is a classic indication of over annealing leading to brass dezincification. There are a few other reasons but dezincification would be near the top of my list without knowing more information.

Dave

 

[kiwijohn]

Looks like the color you get if you sonic clean with too much acid in the mix.

 

[Rocketvapor]

 

[michaeljp65]

deprime cases first. them clean necks with 0000 steel wool.

 

[DLT]

View attachment 1456570This is what Starline says about the coating on the inside of the case necks.
Excuse my scribbling.

That is probably what it is Thanks for that.