Annealing question. Too far?

[Webster]

I annealed a fair bit of .308 brass the other day using a drill and socket. I've done it in a dark room a few times before with good results, but this time I did it with the tv on. I guess with the extra light I heated then quite a bit longer. The stain from the annealing goes past the shoulder part way down the case. The question is, how far is too far? It obviously isn't anywhere near the case head. Just wondering what some more experienced folks might have to say.

Very little if any annealing is done at 750F, it's mostly stress relieving. I'm tired of posting my annealing data acquired under lab conditions. Squeeze a case mouth with pliers, I think you may find it still has decent resistance to being crushed. Compare the force to crush an un-annealed case to one you annealed. If the neck collapses with little pressure it’s definitely over annealed. In that case I would toss them. Any case I tried to crush with pliers took a lot of force.

I have been annealing with a torch. I found 8 seconds safe based on color in a dark room, but due to not counting to 8 accurately and torch variation I was reaching orange color occasionally. I went to 5 seconds for safety. It’s enough to prevent neck splitting. My heat treating/annealing study at my work place found that 5 minutes at 800F there is a drop of only about 2 hardness units. You have to get over 1000F for more than one second before things happen real fast. The color on the cases is not just an indication of how hot it got. Any chemicals or case lube will alter the colors.

 

[Joe R]

Very little if any annealing is done at 750F, it's mostly stress relieving. I'm tired of posting my annealing data acquired under lab conditions. Squeeze a case mouth with pliers, I think you may find it still has decent resistance to being crushed. Compare the force to crush an un-annealed case to one you annealed. If the neck collapses with little pressure it’s definitely over annealed. In that case I would toss them. Any case I tried to crush with pliers took a lot of force.

I have been annealing with a torch. I found 8 seconds safe based on color in a dark room, but due to not counting to 8 accurately and torch variation I was reaching orange color occasionally. I went to 5 seconds for safety. It’s enough to prevent neck splitting. My heat treating/annealing study at my work place found that 5 minutes at 800F there is a drop of only about 2 hardness units. You have to get over 1000F for more than one second before things happen real fast. The color on the cases is not just an indication of how hot it got. Any chemicals or case lube will alter the colors.

The window for annealing brass is quite wide, so don't sweat it too much. Check out the article below.

Joe

 

[ImBIllT]

Very little if any annealing is done at 750F, it's mostly stress relieving. I'm tired of posting my annealing data acquired under lab conditions. Squeeze a case mouth with pliers, I think you may find it still has decent resistance to being crushed. Compare the force to crush an un-annealed case to one you annealed. If the neck collapses with little pressure it’s definitely over annealed. In that case I would toss them. Any case I tried to crush with pliers took a lot of force.

I have been annealing with a torch. I found 8 seconds safe based on color in a dark room, but due to not counting to 8 accurately and torch variation I was reaching orange color occasionally. I went to 5 seconds for safety. It’s enough to prevent neck splitting. My heat treating/annealing study at my work place found that 5 minutes at 800F there is a drop of only about 2 hardness units. You have to get over 1000F for more than one second before things happen real fast. The color on the cases is not just an indication of how hot it got. Any chemicals or case lube will alter the colors.

Oh those necks are soft...big time soft. Is there any safety issue from a soft neck?

 

[USMCDOC]

Some time back we used three different temperatures (300, 400 & 500 degree) of Tempilaq to do some investigation of what was happening to our setup case for a new two torch rotary case annealer. We put thin stripes of each from the point of the shoulder down to the head. The flames were pointed above that, at the middle of the neck. What we learned was that when the 500 degree stuff was burned down to about the same level as the annealing color on Lapua brass, we had some neck spring left and the shoulder bump became a lot more uniform. For the socket and drill guys I have some well tested advice, standardize your flame adjustment and its position relative to the case and buy a cheap battery powered metronome, set it to 60 beats per minute and use that as an audible timer. A friend did this at my suggestion and it worked out very well for him. Another way to do the same thing is to download a fee program off of the internet that will do the same thing. I don't have a smart phone, but it wouldn't surprise me if there were several for them.

The Metronome is a great way to do it if you don't have a machine of some sort. I run mine at 120 bpm..

 

[BoydAllen]

Some time back, for a friend who was working with one of Hornady's now discontinued annealing kits, I came up with the metronome idea. At the time, I had never heard of such a thing. There was no reference to it anywhere. After that, and his success, I posted the idea, and several other shooters have reported back that it has helped them quite a lot. If you think about it there are about four variables....flame adjustment, flame position on the case (including distance) and time. Being able to hear the seconds tick off means that you only have to watch one thing, flame position.

 

[Tesoro]

Erm... kinda.

Remember brass is an alloy.

Can vary in its composition but for our purposes it's mostly copper (Cu) and zinc (Zn).

The risk in over-annealing (stress-relieving might be a better term; we don't want a full anneal which would be too soft) is that a portion of the zinc present can literally burn off, leaving behind the copper which by itself is too soft.


I think what can be observed in that video when the flame begins to turn orange/yellow is the zinc beginning to burn out or oxidize.

Copper melts at 1,984°F, zinc at 788°F. Both will oxidize when heated in air. If you're heating cases to the point a red glow can be seen, temps are at or above the point where zinc will oxidize.

how do you know that when you see a red glow begin that this is at a temp that begins to burn out the zinc??
just wondering why the annealing fellow would tell me to use the glow as the benchmark? i am looking for the first hint of glow in the dark and then back it off a hair. i tried doing it with the lights on at same setting and no way could i see any reg glow. So maybe the way he told me to do it isnt really the red glow that people talk about with normal lighting. My queue is a real dark red spot that I can only see on the inside of the neck momentarily before the case rotates out. As soon as it is out of the flame it immediately disappears.

yes wrong wording on alloy!

 

[Webster]

how do you know that when you see a red glow begin that this is at a temp that begins to burn out the zinc??
just wondering why the annealing fellow would tell me to use the glow as the benchmark? i am looking for the first hint of glow in the dark and then back it off a hair. i tried doing it with the lights on at same setting and no way could i see any reg glow. So maybe the way he told me to do it isnt really the red glow that people talk about with normal lighting. My queue is a real dark red spot that I can only see on the inside of the neck momentarily before the case rotates out. As soon as it is out of the flame it immediately disappears.

yes wrong wording on alloy!

There is no evidence that zinc burns out at the temp we using. The zinc is in solution with the copper, not floating around in it. If zinc burned out the surface would look porous.

 

[Zero333]

I anneal in the basement at night with the TV on to have a little bit of light so I can see what I'm doing.
I chuck them in a Lee lock stud, aim the tip of the blue flame at the shoulder at a 20deg angle, run the drill at about 1.5 rpm per second, hold in the flame till they they start showing a faint dull red (maybe 6 to 7 seconds? ). If the flame is aimed at the neck and not the shoulder it takes less time but the shoulder doesn't get annealed as much.

This is a pic of part of a 308win batch on it's 5th annealing (reloaded 25x times, annealed every 5)

 

[spife7980]

Im just impressed with how straight you got those on a paper towel...

 

[Nvreloader]

Any other guys with this problem,

I am color blind to Red,Green etc.
So I can't see these colors etc.

So, my only option is to use temp-lac heat indicator, correct????
Any other options??

This is with a "Skips" designed gas annealer.

Tia,
Don

 

[Tesoro]

Any other guys with this problem,

I am color blind to Red,Green etc.
So I can't see these colors etc.

So, my only option is to use temp-lac heat indicator, correct????
Any other options??

This is with a "Skips" designed gas annealer.

Tia,
Don

Wouldnt you still be able to see that magic cherry red glow in another hue when in the dark? The whole neck dosent change just a center spot appears inside the neck. Why not try it with someone else to tell u when they first see the glow and maybe it will be easily identifiable in another hue. Never know.

When using std pencil tip torches n recommended distance off shoulder n angle you have some pretty set in stone time ranges to start with for diff cartridges. Ie with my setup using dual torches a 223 will require min 2 and max 3 secs to anneal depending on the headstamp. Havent tried with one torch but my guess be a bit more than double the time.

I had no luck with tempilaq in the case mouth but worked great on case body to show heat transfer.

 

[snakepit]

This metronome site is free and works great on both my computer and smart phone.
Just turn your volume up and count the beats.



http://a.bestmetronome.com/

 

[Webster]

I annealed a fair bit of .308 brass the other day using a drill and socket. I've done it in a dark room a few times before with good results, but this time I did it with the tv on. I guess with the extra light I heated then quite a bit longer. The stain from the annealing goes past the shoulder part way down the case. The question is, how far is too far? It obviously isn't anywhere near the case head. Just wondering what some more experienced folks might have to say.

I would have stopped annealing after looking at the first case.

 

[ImBIllT]

I would have stopped annealing after looking at the first case.

No kidding....

I didn't turn the lights on until I had finished the whole batch. Going to dull red in complete darkness has worked great for me in the past. It's obvious that having the TV on was enough light the dull red wasn't visible until a higher temperature than in complete darkness.

 

[Nvreloader]

Tesoro
I tried it a couple of times using my mapp gas and the socket/drill thing,
all I did was melt the case necks and ruin the brass etc.

Thank God, I used some junker brass and not my good stuff etc,
Never tried it since, until I found the "Skips" design annealer,
which just about finished being built, so I can try it out.

Tia,
Don

 

[Elwood]

I'm not sure if this link will work for you all, but I was always curious as to how over annealed brass would shoot and so did a small test. As already pointed out to me the test sample wasn't big enough.

http://ukvarminting.com/forums/topic/38027-annealing-real-time-tests/

 

[ImBIllT]

So back to the original question. Any safety issue with over annealed brass that does not show a color change below the mid lpoint of the case? I already tossed the three that did go almost to the midpoint. The rest are around 1/4" below the shoulder. Yes they're over annealed. The question is about the safety issue.

 

[Elwood]

So back to the original question. Any safety issue with over annealed brass that does not show a color change below the mid lpoint of the case? I already tossed the three that did go almost to the midpoint. The rest are around 1/4" below the shoulder. Yes they're over annealed. The question is about the safety issue.

In my experience they are safe to use

 

[sparky123321]

Discoloration of the cases is a very inaccurate indicator. Cases cleaned in steel pins sometimes shows little to no discoloration. I "always" use TEMPILAQ to determine if my necks have reached the proper temp and the bodies and bases have stayed within a safe range. I may have a time range in mind from prior sessions, but always confirm whenever starting a new batch.

There's no need to anneal any further down than the necks. Once the neck reach the proper temp they're good to go.

 

[Sheldon N]

They're fine. Shoot them.

Someone posted a test with tempilac on the neck and the base of the case, I think it was 750 tempilaq on the neck and 450 on the base. They held the neck in the torch flame to see how long it would take the 450 degree tempilaq to change, the point at which the case head would start to soften. It took forever, something like 30 seconds, the neck was glowing hot red for a long time before the temperature made it down to the base.