Air cooled brass annealing

[prs]

Is it effective and correct to allow heated case mouths to simply air cool instead of tipping them over into cooling liquid? I was thinking of building a simple pull strip annealing jig and if I can air cool, it will be even simpler yet. Had not heard of such until reading the 4th Cast Bullets Handbook that just arrived. Seems Mike V. suggests less aggressive heating and air cooling can be effective.

prs

[Von Gruff]

There is no need to drop an annealed case into water if the heating dose not include "over heating" . If you look at any of the comercial annealers there is only air cooling, in fact over heating is as bad as not annealing at all.

I give my cases a trip through the case polisher first and then the very first show of colour change to the rainbow-blue is easily seen and is suficient to properly anneal the case. Done in a good light it is easy to see, whereas those that advocate a darkened room cant see a colour change till the case starts to glow and that is way too hot and is why they water drop.

Von Gruff.

[prs]

Thanks! That is easy!

prs

[gray wolf]

I believe water cooling the case is to insure the that the web areadoes not get overheated.
It takes close to 600* F to do the job.

[MtGun44]

The key is to keep from softening the case head area. As long as it stays cool it will
retain the hardness put in a the factory by working the brass (deforming it). If you soften
the case head, the brass is scrap since ther is no way to harden with heat, only permanent
deformation hardens brass ("work hardening"). Cooling rate after heating has zero effect
except to prevent heat from traveling down the case.

Bill

[odoh]

Is it effective and correct to allow heated case mouths to simply air cool instead of tipping them over into cooling liquid? I was thinking of building a simple pull strip annealing jig and if I can air cool, it will be even simpler yet. Had not heard of such until reading the 4th Cast Bullets Handbook that just arrived. Seems Mike V. suggests less aggressive heating and air cooling can be effective.

prs


I always did the water thing myself. As a child what w/Dad being a plumber telling me that heat/heat cycling of copper/brass hardens ~ just the opposite of ferrous metals, I never questioned it. I have observed that brass nuts used on exhaust manifolds tend to be brittle, not softer over time ~ ~ ~ ~ try it out and let us know?

[nanuk]

yup... someone try it out and post the results please?

[qajaq59]

I've air cooled mine for years now. Works fine. Just don't overdo the heat. You don't want it to be glowing bright red. And a room with subdued light makes it easier to see what you are doing.

[akajun]

You guys might think I'm crazy, but I anneal cases for case forming with an acetelyne rig, with my bare hands. I did this the other day making 5.45x39 cases out of 223. If you dont anneal, and I mean get it red hot, the case crushes. Big bottles are cheaper than propane torch bottles

I take my torch and clamp it in my vise, get a good neautral flame going. Grab the case with my bare hands on the head, and rotate it in the flame for a second till it glows, then drop in water. The temp rises so fast it doesnt have time to spead to the head, my hands never get hot, if they do , somethings wrong.

All my highpower brass just get passed in a fish cooker flame for a few seconds till color change and dropped in water.

[felix]

.........The temp rises so fast it doesnt have time to spead to the head, my hands never get hot, if they do , something's wrong....... akajun

Correctly done. ... felix

[NVcurmudgeon]

.........The temp rises so fast it doesnt have time to spead to the head, my hands never get hot, if they do , something's wrong....... akajun

Correctly done. ... felix

Felix, What do you think of holding the case about halfway to the head and rotating the neck and shoulder in the flame of a common parafin candle? When the case gets almost too hot to hold you just drop it onto a damp towel, then wipe the soot off. I tried this on some once-fired Western 29 (could that indicate made in 1929, I found them among about 100 ancient headstamped Krag cases at the range?) So far they are holding up fine. This technique was described in a recent Handloader or Rifle. It was attributed to "an old machinist" who had worked out this method by using temperature indicating crayons. I surely enjoy not having to be in a dark room with a propane torch, and not having to dry recently submerged cases!

[9.3X62AL]

Bill--

Interesting, low-tech method. Does the treated area of the case do the rainbow colors mutation?

[thx997303]

I do similar to the acetelyne torch method, but I use a propane torch.

[Shiloh]

They're held in my hand, turned in a neutral torch flame, when the bluish line is just past the shoulder, dropped into a bucket of water. Grab another and repeat. It goes fast and they look like military brass when finished. With practice and a tempo, they almost all look the same.

Shiloh

[lwknight]

The only reason to tip them over into the water is to know which ones are done and you won't be tempted to pick up a hot one.

[NVcurmudgeon]

Bill--

Interesting, low-tech method. Does the treated area of the case do the rainbow colors mutation?

No colors that I could see, just soot. Maybe annealing in normal fluorescent/sun light makes it harder to see colors. The cases were like-new shiny after tumbling but before annealing. But this way you don't have to SEE anything, each case sends a palbable signal when it is done!

[felix]

Bill, it takes about 250 degrees to start the annealing process for a well made case if I remember reading the curves correctly years ago. Keep in mind the various formulas out there for cartridge brass. 70copper/30zinc gives about ideal hardness/toughness (best spingback is when the alloy ratio is perfect and is perfectly annealed???). Of course, war time supply dictates whatever case chemistry will exist. Annealing occurs for our normal cases beginning at a certain temperature, and the hotter the case temp the more anneal takes place. Dropping cases in water makes the temp go below the demarcation point, so all action stops DOA into the bucket. Always throw small cases into a water bath because coppered stuff has a good thermal xfer even after throwing them down. ... felix

[nanuk]

I bought "Designing and Forming Custom Cartridges" Book by Ken Howell.
in it he talks about temperatures and suggests the hottest flame to get the temp up fast so heat won't spread to the base.

so the acetylene torch setup and fingers would fit in with his theory.

[rbuck351]

Do none of you boolit casters simply dip the necks in your lead pot for a couple seconds? Then into water or a wipe down with a damp rag.

[fishhawk]

well yes i do the lead annealing and have good results with it. steve k

[Von Gruff]

My very first annealing test was with old many times fired cases, that were starting to show the odd neck split, and I did the lead pot dip. Did it on un polished cases and got a bit of leading on the necks that took a bit of removing. (edit to add. I am still using that particular brass with at least another 30 reloads through them with no more losses but annealed regularly)That and the need to anneal when the pot wasn't on had a deciding factor in my choice to go the gas torch route. This is my set-up. 4-5 sec for small cases. 7-8 sec for med and 8-10 for large. I have a seperate socket for each size. I just drop them out of the socket into a steel bowl without water.
http://i667.photobucket.com/albums/vv39/VonGruff/003.jpg

http://i667.photobucket.com/albums/vv39/VonGruff/004-1.jpg

Von Gruff.

[fatelk]

Learn something new every day. I guess I've been drastically over-annealing my brass for many years. I was taught to hold them in my fingertips, rotate them in the flame from a propane torch until the neck glows but before my fingertips get hot, then dump them in water.

I'm quite sure I haven't damaged the bases, as they never get hot enough to burn my fingers, but it looks like I sure don't need to get the necks near so hot.

[nanuk]

according to some "Experts" if the neck "glows" it is too hot and possibly irreversable damage has been done. You should not be able to easily bend in the neck.

but then again, there are numerous examples of just that and they work just fine.
I would also think that the softer the neck the better for Cast. as the lighter loads will still seal, and a death grip is not necessary on the boolit

so the term "YMMV" is wholey appropriate in this issue.

[nanuk]

Hey, you guys that lead dip for annealing

do you have a special mix that you keep just for that? and do you set the temp different for annealing than casting?

[fatelk]

according to some "Experts" if the neck "glows" it is too hot and possibly irreversible damage has been done.
I think what they mean by irreversible damage is damage to the base. So long as the base doesn't get too hot, it doesn't hurt the neck. I've been getting them "too hot" for years and have never had a problem, but I'm not a bench rest shooter either. The neck just gets too soft, resulting in possibly insufficient neck tension and inferior accuracy.

From now on I will watch carefully when I anneal and see how it works.