Baking Brass??

[LIUNA]

I need some advice, I had cleaned my brass (44 Mag) in my tumbler and I put it in the oven at 170 degrees to dry for 20 minutes, and while I was in the garage my wife comes home and decides to bake a cake and sets the the oven temp to 450 degrees to preheat for baking the cake and when she opens the oven to put the cake in, she see's my brass. Now my obvious question, is my brass cooked ( the brass now has a light blue color ), and was the temp too hot for the brass to survive?
I never thought I would be telling this on myself, but what do you guys think. I don't need advice on baking brass, only is the brass of good or bad.

 

[Steve Blair]

Brass must be heated to over 500°F for some time to experience any measurable material condition change. What was the duration of heating?

 

[thefitter]

You are fine, ask me how I know.

http://forum.snipershide.com/snipers-hide-reloading/79597-brass-baked-oven-350f.html

 

[LIUNA]

Not sure how long at 450 degree but probably 5 minutes.

 

[Steve Blair]

Nothing to worry about if that is correct. Cartridge brass is unaffected by temperatures below 482°F, regardless of time. Ken Light's article on the subject is quite informative. I use one of Ken's annealing machines and he has long experience in the area. [br]
http://www.kenlightmfg.com/cartridgecaseannealer.htm

 

[missed]

It has happened here too! im shooting all of it.

 

[Immike]

You didn't hurt the brass with that temperature, it takes a full hour @600 degrees to anneal brass.

 

[LIUNA]

Thanks everyone for your help and advice, I appreciate it very much.
Bob

 

[jlow]

Nothing to worry about if that is correct. Cartridge brass is unaffected by temperatures below 482°F, regardless of time. Ken Light's article on the subject is quite informative. I use one of Ken's annealing machines and he has long experience in the area. [br]
http://www.kenlightmfg.com/cartridgecaseannealer.htm

I guess that assumes that the OP's stated temperature i.e. 450F is correct. So the question is how sure and confident one would be with a 32 degree F difference?

 

[Steve Blair]

I guess that assumes that the OP's stated temperature i.e. 450F is correct. So the question is how sure and confident one would be with a 32 degree F difference?

[br]
Read Ken's article. Even 482°F is a bit specious as it would require laboratory analysis to detect any change. 500°F would require an extended soak to anneal the brass. An oven heating to 450°F for five minutes will not cause a problem. If the OP wants some extra assurance, a short load series of one round per charge increment, starting around .44 Special level, would tell the story.

 

[NorCalMikie]

And I'll bet it came out funny looking as far as color? Throw it in the tuimbler with corn cobb to make it "pretty" again, load it up and go shooting. ;D

 

[jlow]

I guess that assumes that the OP's stated temperature i.e. 450F is correct. So the question is how sure and confident one would be with a 32 degree F difference?

[br]
Read Ken's article. Even 482°F is a bit specious as it would require laboratory analysis to detect any change. 500°F would require an extended soak to anneal the brass. An oven heating to 450°F for five minutes will not cause a problem. If the OP wants some extra assurance, a short load series of one round per charge increment, starting around .44 Special level, would tell the story.

All I am saying is with a kitchen oven, you really don't know exactly what temperature it reached and so need to be careful and take the dial numbers with a grain of salt. The fact is we don't know how long it was in there at what temperature. The comment was for the OP and is no different than telling someone not to take published Max Load numbers at face value.

 

[aj300mag]

Exactly...

The heating element gets a whole lot hotter then what the temp control was set at. It all depends on how close the brass was to the element.

IIRC a light blue color is north of 600°…

 

[LIUNA]

The light blue color was on the surface side, and the 5 minutes includes the preheat cycle, so at 450 degrees is less than 5 minutes.

 

[jlow]

Sounds safe to me, but of course with most reloading stuff that is on the edge, everyone has to make up their own mind in terms of what they are willing to risk.

 

[Big Mc]

Funny no one asked. How was the cake ?

 

[Immike]

Funny no one asked. How was the cake ?

I was wondering if it burned with all the heat it was exposed to. I had no idea that cakes were baked at 450 degrees.

 

[ERGJ]

If you use an oven, preheat to 300*F, turn oven off, put brass in, close oven door, put a SIGN on door and control panel. If still worried, use duct tape around the whole damn thing!

 

[Webster]

I cut the necks off of new 6BR cases and heat treated them in a lab furnace that controlled temperature to +- 2 degrees F. Then measured to hardness.

 

[jlow]

Great work and very interesting data and thanks for sharing!

So the difference between the two is one was treated for 15 seconds and the other for 5 min at the two temperatures. So this tells us that the degree of annealing is both temperature and time related which fits what we know.

My assumption is with the 5 min treatment, there is adequate time for the brass to equilibrate to the dialed in temperature and so this give a relatively true picture of what temperature the brass actually anneals being heated that long, which I presume is somewhere in the area between 80 and 40 HRB. We currently don’t actually know yet what this number is but perhaps you can get that number by testing a piece of unfired brass?

The fact that the HRB pretty much “falls off the cliff” would tell us that even with the 5 min heating time which is slow and much longer than the annealer we use (more like 3-5 seconds), there is not a lot of forgiveness once we go past 800 degree F…..

So another question is since this was done in a temperature modulated furnace, how does it relate to the situation of annealing with torches?

One clue to this is your 15 seconds annealing data. Since brass in the neck would be around 12-14 thousands thick, it would be fair to say that it would be impossible for the brass to attained the dialed in temperature for the majority of the 15 seconds since the brass would start at room temperature and there would be time needed to change to the higher temperature. The bigger the difference, the longer this would take. This I think is the reason why the two curves are different i.e. for the 15 second sample, the actual achieved temperature would be significantly less than the dialed in oven temperature.

The other problem of relating this to what happens with the annealer we use is that it is likely in the opposite situation. The reason I say this is because the heat source which is the flame from the torch is in fact much higher than the desired targeted temperature and so it’s curve would likely be to the left of the 5 min annealing curve and this is the reason why we can anneal in such a short time.

So very interesting and much fruit for thought. Would love to know the HRB of new unfired brass!