softening brass for re-forming
I have some brass I need to radically change for a project. Can I heat the brass and let it air cool to make it softer and then anneal it afterwards?
Heating the brass and letting it cool in air or in water IS annealing. DO NOT heat the heads of the cases because there is NO way to re-harden them. Soft case heads are dangerous when they're fired.
Unless the brass is.........
very old, it could be detrimental to heat it first. Have you tried to alter it without heating it yet?? HTH.
You can do this IF
you stand the cases up in water deep enough to protect the bottom 1/3 of the case. Be careful not to heat the cases past where they just start to turn color, I.E. a Straw color. It is also best not to focus the heat at one point. The fire should suround the cases or place the container on a small lazy susan and spin the susan slowly as you heat them. That is the slow way to do them but you probably don't want to spend several hundred dollars for a mcahine I am thinking. Focus the heat in the area you want to re-form as heat rises and the tops should be ok when you have the focal point heated.
Nothing to it, It's all in the wrist
As an aside, I make short 30-284 cases and end up with a case that is 1.650 long. I do not anneal the cases to make them. I have an 8 step Jones die that does a great job but I am told there are other dies available that are a lot less expensive.
Last edited by Pete Wass; 03-30-2009 at 06:35 PM.
Thank you Pete!!
The 6.5x284 Lapua case is what I'm working with. I've got the Jones form die you speak of, along with one from Butch Lambert and Skip Otto. I've formed Norma 284 brass before without trouble but this Lapua brass is being stuborn.
Let me try a little heat on the shoulder and neck and see what happens. All I'm gambling is a little time and a few pieces of brass.
By the way, I got my Jones clear back when we were trying to form Federal small primer 308 brass to fit a factory 40x 22BR.
I have heard that you can anneal cases by dipping the case neck in molten lead. This seemed to be a great method as it the heat would be distributed evenly. I have not tried this myself, has anyone else tried it and what were the results?
If you find....
That you must anneal, try chucking up a shell holder on your battery drill and while turning slowly and in a dimly lit room, apply heat to the neck/shoulder junction with a small bottle torch. When the brass just starts to turn a dull red, quench with a multi folded wet paper towel. This is an inexpensive and quick way for good annealing results.
Originally Posted by Dave B
Molten Lead for case annealing
Using molten lead works very well for annealing and is a very controllable
Originally Posted by big k
process. You may want to check this thread http://www.websitetoolbox.com/tool/p...ost?id=3169332 also.
I have also experimented with Cerro-Safe insted of lead. With its low melting temperature (<190*F), if I pre-heat the cases to 250*F then I don't get a ring either inside or outside of the case.
Originally Posted by virg
According to Ken Light's instructions and from what a number of people have said on here, heating to dull red is too hot. Ken Light's instructions says Straw Color. That is what my Partner goes for and we have great results.
A friend tried the hot lead and had lead stick to his cases. What did he do wrong?
A friend gave me a bunch
of Lapua cases and I had trouble crunching them; couldn't do it. I discovered that they were several thou bigger in the butt than the Winchesters I use so I can't use them. If you would like them I will be happy to send them to you. They have been pushed back some and are expanded to 30 Cal.
Originally Posted by Dave B
An induction heat treat machine would be great for this purpose. Anyone interested might want to keep an eye out for a used induction machine commonly used for soldering or heat treating of tools, blades, etc.
The business I'm in uses induction heat treating extensively to carefully control the hardness and heat treat depth of carbon steels. It's generally much more precise than flame heat treatment.
All you really need is an induction power source and some copper tubing to make a coil (water cooled).
One could use a round coil and a raise/lower fixture to push the empty cartridges into the coil's induction field. The temperature could be very closely controlled, as well as the location of the heat.
I would hesitate to speculate on today’s prices but in 1998 I was on a design team that did a VERY similar selective induction annealing system. The system annealed the "neck" (crimp end) only of an electrical connector. The cycle time was about 0.4sec, power supply 500 KHz and 3 KW, used a flat pancake coil with shaped concentrator. Back then the system cost was $12,000 and the coils were $2000 each. Note that cost does not include the parts handling or safety guards. Also note that the some tuning was required for even small changes in neck wall thickness.
I would say that even at those prices I could afford to buy enough new brass and toss it when it starts to get too hard to last me the rest of my life.
The reason one gets lead rings (inside and/or outside) using the lead dip method is that the lead solidifies at about 621*F so if molten lead contacts a portion of the case that is lower than that temp it will solidify and "stick". Note that lead shrinks slightly as it solidifies so that it tends to grip the outside but drop out of the inside of the neck.
I found that by rigging a cam operated case handler so that the entry and removal of the case neck in the lead was slow and steady both ways, there was almost no ring formation.
I'm envisioning something "surplus" to use as a power supply and. I happen to have some at the manufacturing facility where I work, but they are all much too big for cartridge cases. We currently operate 6 induction heat treat machines for the production of band saw stock. We make our own inductors from copper tubing (they are all water cooled)as well.
I think that a simple inductor coil could be produced by many of the tinkerers we have on this board.
A secondhand Leco carbon determinator might just fit the bill. They are fairly common in the metals industry (foundries, steel mills, etc). If you could find one where the "determinator" part is broken, all you need is the power supply, the inductor, and a timer. You would probably still be into it for several hundred dollars though.
Lead bath quenching is fairly common in strip steel processing, but I wouldn't want to be the one to recommend that a private individual should use such a technique. Not that it doesn't work, only that there are safety and legal concerns.