PDA

View Full Version : Case Dipping



HEAD0001
06-27-2009, 02:06 AM
Is anybody annealing their cases by dipping their cases into their casting pot?? If so, please explain how you do it. Thank You, Tom.

snaggdit
06-27-2009, 02:12 AM
As an old fried used to say, no fair thinking! I had heard of standing them up in water and using a torch on the necks but dipping in the melt? Brilliant! Looking forward to a detailed explaination from a practicer.

Jim
06-27-2009, 02:48 AM
In "Principles And Practices Of Reloading Ammunition", Earl Naramore discusses this. I have to agree with him that the average electric lead furnace does not get hot enough to anneal cartridge brass, regardless of the alloy in the pot. However, the method I use is certainly not scientific and closely controlled, so I don't have much room to talk.
Mr. Naramore says heating the case to the point that it begins to turn blue is about as close as one can get without scientific equipment. I have a metalurgist's book that charts the color of various metals at various temperatures and, according to this metalurgical engineer's book, blue is the color at which cartridge brass begins to soften and give up it's temper & memory.

I'm gonna' hit the big red knob on my mouth now.:roll:

HEAD0001
06-27-2009, 03:31 AM
I am by no means a metal guy. And I have never used a thermometer for my casting. So my question is simple. Can you get your lead melt up to about 650 degrees?? Or slightly higher?? That is the temperature range needed to anneal brass. Or at least I think it is?? Tom.

Bret4207
06-27-2009, 07:58 AM
I recall reading that one guy used hot lead and a temp stick, as temperature sensitive type of "paint". He stuck it in the melt till the paint turned or ran, however it works, I forget.

I always just used a propane torch, heat to upper portion till the blue is running down the shoulder, or down to wards the base in stuff like the 32 S+W, and tip over into a pan of water. Seems to work fine.

higgins
06-27-2009, 11:42 AM
The lead dipping method is described in John Wootters The Complete Book of Practical Handloading. Paraphrasing, set your lead pot thermostat at 750-800 degrees, get a vial of light machine oil. Grasp a case by the head with bare fingers, and dip it into the oil about half its length. Shake off excess oil and dip the neck, shoulder, and about a quarter-inch of the body into the lead. Just as you begin to feel an uncomfortable degree of heat in your fingertips, drop the case into water. Advantages given are you know the temperature being applied (assuming thermostat is accurate or you have a thermometer), and you cannot stand enough heat in your fingertips to allow overannealing. Wash cases in detergent to remove oil. A long time ago, I formed 8mm Mauser cases from military 30/06, and annealed the case mouth and shoulder of the formed cases using this method. I still have a few of the cases in service, and they've been loaded many times since forming. I've never used a thermometer so I have no idea what the lead temperature was. I did notice that the newly annealed area did not have the obvious blue tint seen on commercially annealed brass, but was only slightly discolored. I didn't use the oil dip, I may have used powdered graphite, and I don't recall lead sticking to the brass being a problem if you let the cases get hot enough, but be sure to check inside the cases for small pieces of lead.

Well, I managed to leave out possibly the most important part. Wootters' book recommends 8-12 seconds, not more than 15 seconds.

HEAD0001
06-27-2009, 11:58 AM
I wonder how long you need to leave your case in the lead. I realize you and others have said-until the case is too hot to hold onto. However that would be determined more by how long the case was-rather than the actual time. I imagine it would take longer for a 300 Winchester case to burn your finger-versus a 45 Colt case.

I was thinking if I could get a thermometer and control the temp that I could hold the brass with a pair of pliers if I knew how long to leave it in the lead??

I want to anneal some 45 Colt cases.

I ihave tried the torch method in a pan of water, but I am not getting a good even heat around the case. And I can not justify the cost of the rotating annealing platforms.

Why did he use the oil??

There has got to be a way to do this. We just need to get some good data. Tom.

felix
06-27-2009, 12:18 PM
Annealing anything depends upon temp and time together as a combined unit. However, depending on the material to be annealed, a set minimum temperature is paramount for that material. Obviously, there is a maximum temperature because the material will melt or evaporate at that point. For lead and brass alloys the minimum temp is somewhere around 300F. ... felix

markinalpine
06-27-2009, 12:25 PM
...dealing with annealing bottleneck cartridges: http://www.24hourcampfire.com/annealing.html
and
http://carteach0.blogspot.com/2009/06/annealing-case-necks-simple-and-safe.html
The molten lead dipping method mentioned by higgins uses oil to prevent the lead from sticking to the brass.
Holding the cartridges with pliers would eliminate the heat to the fingers (in effect, forcing you to drop the brass), which might allow the head (or base) of the case to get too hot, softening it, which is a big no-no. Read the articles I referred to see why you don't want to ever allow the head of a cartridge case to be softened by annealing.
Straight walled cases usually don't need to be annealed, since they aren't stretched when fired as bottleneck rifle cartridges are, then resized in full-length resizing dies. Stretching and resizing work-hardens the brass, which is what the annealing cures, so the cases don't crack when resized, or worse split when fired.
Please read those articles, and good luck,
Mark :coffee:

felix
06-27-2009, 12:34 PM
Mark, holding the brass with naked hands is a good way to measure "no annealing" at that point. You just cannot hold anything near 200 degrees, and that is way below any annealing temp whatsoever. ... felix

Lead Fred
06-27-2009, 01:42 PM
I use a coleman stove, and with my themometer I can set the temp right at 650, and it holds.

I use a curved lock pick though the primer hole, and one has never fallen off.

If you tumble your brass beforehand, the lead wont stick to the inside.

Does a more even job than a tourch around the outside

WildmanJack
06-27-2009, 02:38 PM
I bought a cheap hole saw, took the drill bit out and put a wood plug in the saw part to take up some space. Put it in my drill, put a case in it and spun it in the torch till it just started to get the slightest red, then dropped it in a box to let it air cool. I think dropping them in water may reharden the brass, but I may stand corrected on that thought. Just my 2 cents...
Jack

felix
06-27-2009, 02:47 PM
Brass we use contains nothing that will harden it upon dropping. The idea behind dropping brass is to stop the heat treatment right now. ... felix

snaggdit
06-27-2009, 02:56 PM
Brass we use contains nothing that will harden it upon dropping. The idea behind dropping brass is to stop the heat treatment right now. ... felix

OK, then it isn't like steel, that will anneal when heated dull red and air cooled but harden if heated red and water quenched. I assume included impurities in the steel account for this where as you state brass does not have this.

woody1
06-27-2009, 02:56 PM
When annealing brass cases you need to drop them in water to stop the heat from traveling to where you don't want the annealing to occur, ie the body and cartridge head. Water quenching brass does NOT harden it. Brass is hardened by working it as you've done in resizing several times which is why you're annealing it.
Regarding annealing in molten lead, one needs to hand hold the case to avoid annealing too much of the case. I know of no other way to avoid that. Regards, Woody

I guess felix was posting while I was thinking.

rockrat
06-27-2009, 03:12 PM
I remember realing long ago, that when your use your lead pot to anneal, you hold the case in your fingers (so you won't anneal too far down the case) and dip the case mouth in powdered graphite first, then dip in the hot lead. Guess to keep from the anneal to go too far, you could then drop the case in water. I think the local tractor supply might have the powdered graphite, as it is used to lube the planters. You wouldn't want oil on your expensive seed.

Recluse
06-27-2009, 06:57 PM
Straight walled cases usually don't need to be annealed, since they aren't stretched when fired as bottleneck rifle cartridges are,

Way back when, I used to anneal my .38 Special match brass. It sure did help cut down on the case splitting.

I just use a heavy pair of leather gloves and roll the brass in between my thumb and forefinger while hitting the end with the torch. I usually anneal with the lights out i the shop so I can better see the effects of the torch.

Brass seems to conduct heat pretty well--I wouldn't be too worried about "uneven" heating that much.

:coffee:

markinalpine
06-27-2009, 11:24 PM
...about annealing brass cartridges for some of you to not even bother reading: http://www.realguns.com/Commentary/comar46.htm
Mark [smilie=1:

ps, by the way, Recluse, I stand corrected. Most of my experiance reloading has been for semi-auto pistols, with taper crimp cases. I understand now that the process of roll crimping is hard on those types of cases, so annealing would extend their lives.

runfiverun
06-27-2009, 11:26 PM
http://www.lasc.us./CartridgeCaseAnnealing.htm
this will explain what you are wanting to do.