Induction Heating to anneal cases


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Bullet
August 27, 2008, 08:41 PM
I’ve been looking at Induction Heating to anneal cases. It seems that the temperature could be controlled exactly. This could probably be used for annealing cases. Below is an example.

http://www.ameritherm.com/video_annealing.html

Any opinions welcome

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DWARREN123
August 27, 2008, 08:54 PM
Costs over a porpane torch. Precise placement of cases to be annealed to control temp.

Ed_E
August 27, 2008, 11:27 PM
I posted almost the same question on another forum and got zero response. I also think this is an ideal way to anneal with very good control. I looked all over the internet and saw many systems, some may be applicable to annealing cartridges. Big disadvantage is cost. Most all are done for production annealing applications and so are large and require running water to cool the coil.

I did see a couple of videos of home brew annealers but they were very jury rig and it seems were done just to see if they could do it.

Maybe some day we will see a small unit with self contained water circulation.

Bullet
August 28, 2008, 01:01 AM
I e-mailed the company listed above about this and will post the results.

My hobby is target shooting. I reload my cartridges and my question is in regards to the brass cases I reload. When firing and resizing my cartridges the brass becomes work hardened, which some reloaders try to anneal to extend the brass life. The methods used by most reloaders seem crude and involve some guess work. I ran across your site and wonder if induction heating to partially anneal the case neck (bring it back to it's original softness) would be possible? Only the neck and part of the shoulder of the case would need to be annealed. The lower ¾ of the case has to remain as from the factory (not annealed) to remain strong enough to take the pressures involved when shot. Some reloaders set their cases in water to make sure the lower ¾ of the case doesn’t get heated when they try to anneal using a torch. If the induction heating process could be used for case annealing there would probably be a lot of reloaders interested, if the price of the equipment to do this was not prohibitive. Does this sound like something that would work and what would the equipment to do this cost?

If you have any question about the above I'll try to answer it.

Thank You,

snuffy
August 28, 2008, 01:02 AM
IF you could control it precisely enough to just heat the front 1/3 of a case, then it would work. If, again, it would work on a tube, and not need a solid piece of material-----. But the expense for that unit would buy an awful lot of new brass!:rolleyes:

Ed_E
August 28, 2008, 01:20 AM
"IF you could control it precisely enough to just heat the front 1/3 of a case, then it would work. If, again, it would work on a tube, and not need a solid piece of material-----. But the expense for that unit would buy an awful lot of new brass!"

When surfing the web for annealing equipment I saw applications for heating tubing. The coils used for heating can be constructed just about any way and size you want and the heating area is focused upon the area inside the coil. The frequency of the exciting current, the magnitude of the current and the time of exciting are adjusted for the application.

Bullet
August 28, 2008, 01:31 AM
Here is a video of a tube -

http://www.ameritherm.com/video_heatingtube.html

And some others -

http://www.ameritherm.com/videoindex.html

Walkalong
August 28, 2008, 07:50 AM
The tried and true methods work so well, and are cheap, but if you try it, we would all be interested in the results, I am sure. :)

Bullet
August 29, 2008, 12:06 PM
I received a reply from Ameritherm, Inc.,

Induction is a prefect fit for brass annealing. The smallest unit we have available at this point is a 1 kilowatt, our HOTSHOT-1. It sells for about $5,000.00.
We are working on a unit that will sell in the $1,000.00 range, but it is not available at this time.

A little to expensive for me, but If a unit could be made for less $$$ I think that Induction Heating to anneal cases would be the way to go.

Steve C
August 29, 2008, 12:27 PM
Hmmm, $5K for a better controlled method of annealing old brass or just take the same amount of money and buy 10,000 new factory cases. I think the $10 plumbers torch from the Hardware store and a pan of water is much more cost effective.

Ed_E
August 29, 2008, 12:42 PM
"Hmmm, $5K for a better controlled method of annealing old brass or just take the same amount of money and buy 10,000 new factory cases. I think the $10 plumbers torch from the Hardware store and a pan of water is much more cost effective."

Definitely true. However, if an annealing set up could be put together for less than $500 I think there would be a market. I have trouble being sure I get consistent results with the manual method. As I said in another forum, the positive is the control of heat but the negatives are the cost and complexity. In that forum someone brought up the possible bad biological effect of radiation from the RF annealers. Something that would be a problem for non-industrial heaters.

Bullet
August 29, 2008, 01:12 PM
In that forum someone brought up the possible bad biological effect of radiation from the RF annealers. Something that would be a problem for non-industrial heaters.

I would like to know if that is true, if so this wouldn’t work at all.

snuffy
August 29, 2008, 01:23 PM
In that forum someone brought up the possible bad biological effect of radiation from the RF annealers. Something that would be a problem for non-industrial heaters.

Cell phones are supposed to cause brain cancer, don't you know!?:barf:

We use induction heaters at the axle plant where I work. They're used to heat bearings to be shrunk on a shaft. There's signs all around the area where they're used, warning anybody with a pacemaker for their heart to stay away!


Now I know almost nothing about how they work, and I don't yet need a pacemaker, but that is one thing I DO know about them.

That reply from the company was very generic in nature. Do they realize the front third is ALL we want hot?

We are working on a unit that will sell in the $1,000.00 range, but it is not available at this time.

Even if it sold for $100.00, I wouldn't buy it. I load rifle cases until they split the neck, then toss them in the re-cycle bucket.

Bullet
August 29, 2008, 01:49 PM
However, if an annealing set up could be put together for less than $500 I think there would be a market. I have trouble being sure I get consistent results with the manual method.

I agree.

Even if it sold for $100.00, I wouldn't buy it.

I would if there are not health concerns. With the price of brass these days annealing would make the cases last longer and give more consistent neck tension.

brickeyee
August 29, 2008, 03:01 PM
Induction heaters create very strong AC magnetic fields.

The pacemaker issue is that the magnetic field can couple into the pacemaker leads in the body and disrupt its operation.

The pacemaker will not be able to sense the heart's electrical activity since it will be horribly overloaded and can fire NOT in synchronization with the normal beat, or possibly not at all.

Either can result in the heart not beating properly.

The general health impact is very small, since the field strcngth drops off very quickly (distance squared).

Arc welding and a pacemaker are a bod combination also.

Bullet
August 29, 2008, 04:44 PM
Posted in another forum -

One problem that folks do not realize is that brass hardness within a lot# may vary as much as 13% in rockwell hardness due to mixture of the alloy. This inconsistant Rockwell hardness gets blamed in a lot of different areas (other than the real cause) and annealing is one of them.

I never heard this before. Does anyone know if this is correct?

345 DeSoto
August 29, 2008, 07:04 PM
How about if you were to find one of those old timey electric soldering irons with the big fat tip on it. Seems to me that the tip could be turned down to the diameter if the case neck, just enough for the tip to stick in just to the shoulder. I'll bet those things could get REAL hot...:D

Ed_E
August 30, 2008, 03:33 AM
Well, they can melt solder. Interesting idea though. I have an IR temperature measuring device and if I still had that clunking big iron I would give it a try for temperature. Don't need to solder sheet metal any more. I will still try it on one of my smaller soldering irons anyway.

brickeyee
August 30, 2008, 11:41 AM
650 F sticks in my mind as the temperature for annealing cartridge brass.

Very few (if any) soldering irons get that hot.
Most are designed around eutectic solder (63/37 around 360 F).

Bullet
August 31, 2008, 11:51 AM
I asked about induction heating on another forum and got this interesting reply -

One problem that folks do not realize is that brass hardness within a lot# may vary as much as 13% in rockwell hardness due to mixture of the alloy. This inconsistant Rockwell hardness gets blamed in a lot of different areas (other than the real cause) and annealing is one of them.

I had an engineering firm Rockwell test cases. The results were so depressing, I can't find the positive in it.

PMC brass made in Korea was much harder and consistant than Rem, Win, and Fed & Weatherby was real soft. OF course, there could only be one Lot# of brass tested, Lot # to lot # could also be a whole can of worms.

It would be very interesting to see an engineer that had unlimited access to Rockwell testing do an extensive test on brass. No doubt that this test would indeed shock us all with the little sampling that I had done.

Walkalong
August 31, 2008, 04:47 PM
I never heard this before. Does anyone know if this is correct?
I would not doubt it for a minute, but no, I don't know.

GaryL
August 31, 2008, 10:10 PM
One problem that folks do not realize is that brass hardness within a lot# may vary as much as 13% in rockwell hardness due to mixture of the alloy. This inconsistant Rockwell hardness gets blamed in a lot of different areas (other than the real cause) and annealing is one of them.

Annealing will also change the hardness, that is the purpose. So depending on how consistent the annealing process was, and where the measurement was taken....

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