DIY Electrical Annealing Of Rifle Cases

J

JeepHammer

Moderator
Electrical Induction Heating/Annealing of metals,

A DC electrical current is 'Flipped', Alternated from positive to negative in a conductive material (Wire Or Tubing) VERY quickly,

This produces an alternating magnetic field (Electro-Magnetic Link), and produces MAGNETIC 'Eddie Currents' in anything electrically conductive within range of that conductor.

In the case of induction heaters used for annealing (heating) of rifle brass,
That would be a coil of copper wire or copper tubing.

A coil gives you 360* heating of the brass,
The brass heats from the inside out, the conductor coil doesn't need to get hot while INDUCING the case to heat up internally.

No open flames, no uneven heating, precision control of the heating process since you can time the case interaction with induction coil.

Just for the record, this is how the large manufacturers control heat saturation when the cases are annealed at the factory...

-----------------------------

Induction units are HORRIBLY overpriced.
They are VERY simple to build from scratch, and very cheap to buy the components to build your own...

Most guys I know think anything electrical is "Magic Smoke' based and electrical components run on 'Magic Smoke',
Fry something and let the 'Magic Smoke' out and the device doesn't operate anymore... :eek:

*IF* you can change a breaker in a breaker box, or change a wall light switch or plug outlet without getting electrocuted,
Then you might consider building your own Induction Heater and save some money...

------------------------

SOME IDEAS & SOURCES...

ONE AT A TIME FOLKS,
The guys that are going to anneal one case at a time...

Use a SOLID WIRE and a TIMER to operate the induction heater.
The wire has time to cool down while you are changing out cases...

Amazon has this little (120 Watt) unit with INSULATED solid wire coil for CHEAP $$$$. ($23.99 right now)

http://www.amazon.com/Yosoo-5V-12V-...60222123&sr=8-3&keywords=DIY+induction+heater

You will need a 12 Volt DC power source, and a timer to control how much heat each case gets.
Digital Timers are anywhere from $5 to $100 depending on how many 'Extras' you want...
The $5 units work fine as long as they have a 'Memory' function and you don't have to enter the 'Cook' time each and every time.

The one I used for these small scale induction units cost me $7 off eBay...

http://www.ebay.com/itm/Trigger-Cyc...f4c03e1&pid=100009&rk=1&rkt=1&sd=281744723381

You are looking at another $20 or so for a 12 volt, 30 Amp power supply,
Or you can just use a car battery until you get things figured out...

Timer switches induction unit On/Off at a PRECISE time, giving you a PRECISELY annealed case, depending on time of heating cycle, which you will have to figure out using some temp sensitive color change paint or QUICKLY taking the temp of the case with thermometer or pyrometer.
 
Last edited:
VOLUME ANNEALERS,

For the guys a little more handy with building stuff,
And wanting to do a LARGE number of cases,
Consider a higher powered unit that DOES NOT switch on and off,
The time in the induction coil is controlled by a timer,
But the EXPOSURE is limited by dropping the case INTO, and OUT OF the coil.

You leave the induction unit turned 'ON',
The timer drops the cases into the coil, and out of the coil to control the amount of heating/annealing that takes place.

Now, this takes a larger unit since you are using TUBING instead of a solid wire,
And I STRONGLY RECOMMEND you use a cooling system in that tubing!

Remember, the tube/wire coil gets hot along with the case inside the coil,
So cooling a continuously 'ON" coil is pretty much mandatory....

This unit from Amazon comes with a TUBING coil, you will have to supply pump and NON-CONDUCTIVE tubing, cooling liquid. ($64.89 right now)
(I used an aquarium pump/tubing and a bucket)


http://www.amazon.com/1000W-Frequen...60222123&sr=8-2&keywords=DIY+induction+heater

This particular unit runs 1,000 Watts,

---------------------------------------

At $37.99 and 1,000 Watts, this is a pretty good idea also,

http://www.amazon.com/Yosoo-Voltage...60222123&sr=8-1&keywords=DIY+induction+heater

These are probably made in the same factory in 'China', but for the price and already assembled, it's hard to walk away from a 'China' product in this case.

With these two choices, you will probably want to bump up to 24 or 36 Volt DC power supply...

-----------------------------------------

NOW, JUST FOR PRICE COMPARISON,

1,000 Watt 'Nut Buster' hand held unit with a cheap power supply included, No timer on this one...

http://www.amazon.com/Induction-Inn..._UL160_SR160,160_&refRID=1WEJEY8XW65SZNMKG3EQ

The 'Annie' with a 0.1 second timer ($7) and solid wire inductor (no continuous use), 1,200 Watts, $499

http://www.fluxeon.com/Annie.html
 
Last edited:
FOR SOMEONE WANTING TO BUILD A VOLUME ANNEALING MACHINE,

SOME THINGS THAT HAVE WORKED FOR ME...

To keep the tubing/coil from contacting the brass rifle case directly,
Use high temperature fiberglass tube on the wire or tubing.
3 feet is like $3, so it's dirt cheap...

If you use a 'Drop Through' type production annealer, I had an issue with keeping the case CENTERED in the coil.

I solved that one with a CERAMIC (Non-Metalic, Non-Conductive, High Heat) TIG welding gas focus tube.
#8 size gas tube for MIG welding torch has a 1/2" center hole and is ceramic/high heat/high temp, about $1 each, and sits in the coil to center the cases as the fall into the coil.

MIG gas cones have a funnel shape to start with, so they work really well for dropping a case into, having the cone center the case.
Nothing like 'Self Aligning' when you are doing production so things don't screw up when you are watching cartoons or looking for a cold one while watching the machine work!

Since it's ceramic, it's invisible to the magnetic 'Eddie Currents' that heat the brass from within, it doesn't melt or short anything out, and at $1 each, if I drop and break one once in a while it doesn't bust the budget replacing it.

Commonly available, and I use the 'Long' version (about 3" long) to stand the case up in the coil dead center so it heats evenly all the way around.

*IF* you are going to 'Board Mount' your components (Timer, Induction Module, Power Supply) do it on a NON CONDUCTIVE material, like Plexi-glass,
Then mount the board in your project case, which can be a metal box if you choose.

The non-conductive platform keeps issues with a 'Ground Loop' or stray shorted circuits from happening when you mount the modules.
Makes things MUCH easier from the start when you aren't worried about short circuits to start with!
 
Last edited:
JeepHammer,

PLEASE READ THE BOARD POLICY ON POSTING COPYRIGHTED MATERIALS.

There is an older post (2 years?) on this topic with links to videos showing annealing the case. He used a commercial mechanic's hand-held induction heater for breaking nuts loose by making a timer circuit for it.

It is correct that many induction heaters are more expensive than required for case annealing. Some very simple circuits are available, though the simplest ones are not very efficient and make extra heat in the components.

The operating principle is quite simple. The coil acts as the primary coil of an air-core transformer and the object being heated is like a short-circuited secondary that gets very hot due to the induced current flow inside it. This is the reason power transformer cores have laminations. Without them, a solid iron block would act as a short-circuited secondary and the induced current would flow around in it (an eddy current). The use of higher frequency AC makes the current paths small, so that even something as thin as a case mouth doesn't interrupt the current path like a transformer lamination can for 60 cycle AC.
 
So, no pictures unless you took them yourself...
OK, got it...

I guess if interested they will have to click the links...
 
Last edited:
Yes. Links are fine for now (though some of the IP attorneys have been looking at limiting linking, so far to no practical effect). From the user end it look like we're just giving them free advertising and they should be happy about it, but the law says only they get to make that call and control who writes their ad copy.
 
Scorch said:
Propane torch from Harbor Freight- $21.

KISS still applies.
Click to expand...

That would be correct, keep it as simple and cost efficient as you can to PROPERLY do the job...

The conversation on annealing got started as 'Am I Doing This Right' type thing,
Then branched out into what 'Right' means.

I don't know anyone, including myself, that did the annealing correctly with a gas torch.
Since I couldn't do it 'Correctly' with a gas torch, no matter how much time & effort I threw into the project,
I asked the guys at the factory how they annealed cases, and I was shown to the electrical induction annealing machines,

AND,
The factory engineers explained why gas annealing doesn't work in production facilities,
And why I was NEVER going to get my gas annealing operation running to produce 'Correct' cases.

I'm a dim bulb sometimes about things, but I'm bright enough to at least listen to the experts when they try to give me advise!
 
Well, actually the military annealing specs center around controlled use of flame. I do think, though, that it is easier to control an induction heater with a timer to get consistent results. I've experimented with a couple of designs to get the efficiency up and will show how when I get more time.

Here's the thread I was thinking of from late 2009. Unfortunately the movie link is broken now.

Also, I bought a couple of metal plates with pins for 223 and 308 cases years ago. You heat the plate to 700°F and just set case mouths over the hot pins for about 20 seconds each in a round robin. Worked OK as an alternative heat source, too.
 
I really don't currently anneal my brass, but after reading this, I think I will build one of these in the not too distant future. There are plenty of other things I could use an induction heater for too.
 
I've gone to induction heating for a ton of things,
Nothing like getting that rusted bolt to break loose when NOTHING else worked,

Don't think I've broken out the soldering iron or torch for common soldering or silver soldering in years,

Brazing paste and induction heating make putting on those vent ribs, sight mounts, ect. a snap, and you don't knock around small parts stacks,
You get the stack right, then lower the heater around the parts, wait a minute and remove heat... DONE!

The good thing about induction & gunsmithing is you don't ruin the bluing, just remove bluing where the new rib, or sight block, ect. is going to go, Flux the area, apply silver solder and heat.
You never reach the temp that destroys the bluing outside of the work area.

A 'C' ferrite block allows you to apply heat to 3/4 of the work area, NOT applying or reducing heat to the area you don't want...

I find it VERY handy for things like brazing in pins that you don't want to come back out.
Those side handle AR uppers are a prime example, the left side cocking handle ALWAYS shot loose, braze an insert into place for the bolt to fit into and that doesn't happen anymore.
Brazing that gas tube on the top of the bolt carrier stops gas leaks, and keeps that key in place even if the screw holes are stripped or screws missing.

Those aluminum filler rods work very well with induction heating, a lot like brazing, you can fill in holes in aluminum, gouges, ect,
Join two aluminum pieces WITHOUT that big nasty TIG weld bead sticking up.
Examples are when you need to join two aluminum sight rails to get the height you want for proper eye alignment, or adding rings to a base that wasn't made for them.
Just grind/file a flat mating surface, use the aluminum rods and induction heater to 'Aluminum Solder' them together.

I've built these little case annealers & 'Rust Busters' for the guys around here, $5 project box, some eBay electronics, off and running for around $100.
For those guys the price gets jacked up about $20 to $40 for the power supply, I normally won't let them run on one of my 'Jury Rigged' salvaged transformer power supplies, and an Amazon or eBay power supply is $20 to $40 extra, with 'Soft Start' built in to keep them from burning things up...

Pretty handy gadget to have around a shop, but if you are just reloading plinking ammo and you don't fiddle around in the shop with anything, it's probably not worth the $100 to build.
 
Unclenick,
ATK got the standards for military brass changed to civilian standards in 2012, and the flame annealing is out, induction annealing, the same way civilian brass has been done since the 70's, in the door when they took over Lake City ammunition plant.

Probably had something to do with that HUGE 'Civilian' government contract homeland security pushed through causing all the shortages in components & loaded ammunition.

Homeland wanted sealed bullets, sealed primers, crimped primers, ect., built to military specifications, and the 'Civilian' plants couldn't keep up,
So ATK simply got the the 'Military' standards changed to what 'Civilian' contractors were making at the time.
Military cases since 2012 are EXACTLY the same as SAAMI cases now, I can't find one iota of difference, and once I learned about the 2012 thing last year on a tour of the Federal plant in Anoka, MN. I know why...
(I'm always the last to know anything :p )

ATK is partnered with General Dynamics, and much of the brass was coming in marked 'General Dynamics' with 'Federal' head stamp when I was up there.
I don't know if ATK owns General Dynamics, or the other way around, or it's a partnership, but truckloads of General Dynamics brass was flowing into Federal with Federal head stamps...
The plant was running 24/7/365 and probably 50 trucks unloaded on the day we were roaming around up there.

This year we went to Remington, and they were making their own brass on site.
Don't know what Winchester is up to, haven't been there in a few years.
 
"I've built these little case annealers & 'Rust Busters' for the guys around here, $5 project box, some eBay electronics, off and running for around $100.
For those guys the price gets jacked up about $20 to $40 for the power supply, I normally won't let them run on one of my 'Jury Rigged' salvaged transformer power supplies, and an Amazon or eBay power supply is $20 to $40 extra, with 'Soft Start' built in to keep them from burning things up..."

JeepHammer

Questions about this. What power supply? How did you build in a soft start? What coolant are you using when you leave the unit on to anneal? Got any pictures?
 
Most of the smaller eBay or Amazon power supplies are 'Soft Start' since they are directly transformer fed.
The volts/amps 'Come Up' as the thing powers up.

It's when you are jury rigging an existing transformer for full time/full current output and try to switch it 'On/Off' is when you run into surge issues.
One of the draw backs to 'Jury Rigging' things sometimes.

This is my picture so I guess I can post it if I want to, all rights reserved of course, and I don't take many pictures, since I sell some of this stuff, best not to give away all your details and goodies for free...

image_zps5wywarrs.jpg


Upper right aluminum box with fan is the power supply, about $20 off eBay for low power units.
These power supplies come in all different voltages and outputs,
The higher the output, the more they cost...

The power supplies I run for two units at a time run closer to $50 each, at 1,500 Watts, they will EASILY anneal two cases through two of the smaller induction units in about 2.5 seconds, more or less on time.

What you see is,
Upper left, Power Supply,
Black thing in the middle is a 'Shunt' needed for the Ammeter,
The black thing left is fusing for the different circuits,
This unit powers two annealing coils per circuit, 3 circuits, for a total of 6 cases at a time.
The 'Red' circuit boards are timers/latching relays,
The red circuit boards right are voltage controllers to the 3 different sets of induction heaters.
This allows me to anneal 3 different caliber cases at the same time, or to run all 6 annealers with the same cases.

Those voltage controllers allow me to put more or less 'Heat' into the cases for the same time period since all 6 case stations dump 'In' and 'Out' of the coils at the same time.
It allows me to fine tune the amount of heat the cases get in any given time period,
AND,
I can adjust the time the cases stay in the coils, both time & heat intensity to keep the cases from 'Tinning', yet reaching proper temp to do the annealing job.

This is WAY more complicated than a home loader needs,
All a home loader needs for one at a time cases is power supply, the annealing unit, and a timer.

You can eiter control the time the case stays in the coil,
Or,
You can control how long the annealer coil stays 'On',
Most 'One At A Time' guys should probably go with the timing the unit 'On/Off' time rather than trying to build something that drops cases into a 'Hot' coil precisely,
There is a lot of mechanical/electrical timing issues there,
But it's actually not that difficult if you have a case feeder...

You simply use a solenoid to dump the annealed case out,
-Drop the fresh case in, and connect that solenoid to a timer.

The coil is always 'Hot', the case timing-- Drop 'In' and 'Out' is how you control the amount of annealing that happens.
 
Last edited:
This is the only picture I have currently of the unit controls set up...

image_zpsewbwkiqu.jpg


The power supply is upper right, under the relay rail.
This is low amperage electronics that kick larger relays for higher power applications.
Lower amperage keeps the small relays on the circuit boards alive MUCH longer, up to 1,000,000 cycles,
While you wouldn't get but 100,000 out of them at full amperage.

The common relays on the rails are $1 each, and make more sense to replace than the circuit board mounted, low amperage relays...

These relays also control case drop/dump solenoids, which are higher power, around 8 Amps each.

-------------

I have NOT been able to find a way to feed the induction coils other than pairs.
Case feeders are the issue, they will only support ONE 'Y' each, so a case feeder for each pair of annealers.

If anyone knows an easy way to make one case feeder support multiple applications, I'd sure like to know about it!

Since you can build a case feeder for about $15 from a 5 gallon bucket, it's not the number of case feeders, but the space they take up above the annealing coil sets...

I have to separate the annealing sets to make room for the case feeder bins,
So I run them on a 2-2-2 basis.
What ever is in the case feeder for that particular 2 annealing coils, I can adjust the induction coil to anneal correctly for that case.

--------------------

Now, production cases at the factory run on a continuous conveyor through an 'Open' ('C' type) coil.
They do MILLIONS without stopping, and that open coil saves a ton of time.
I didn't want to build the support gear for a coil that size!

When you use a 'C' type coil, you have to rotate the case for even heating,
I prefer to use a circular coil and simply drop the case through it,
Works best for the size of production I'm currently doing.

Someone doing a lot less brass than me would EASILY have the time to drop the coil down over a brass, anneal it (Timer on the induction coil),
and remove/replace brass by hand.
Still only takes about 5 seconds per case when you do one at a time with induction heating and a fairly powerful induction unit...

Is this what you were asking about?
 
Just for the record, this is how the large manufacturers control heat saturation when the cases are annealed at the factory...
Click to expand...

Do you have a video link? The only case forming production I have seen used open flames for annealing.
 
Like I said before,
Cooling a tube type coil is as easy as a bucket of water, some aquarium tubing and a little water pump.
I just recirculate the water. No big deal...

NON-Conductive tubing is a requirement, you don't want to short out the induction, so aquarium tubing or any kind of latex tubing will work fine.
 
I didn't realize ATK had changed that standard in 2012, so you weren't the last to know after all. My military info sheets are mostly old. I had heard the pressure measuring had gone to SAAMI conformal transducers in the most recent SCATP 5.56, but that's all. Now that ATK has spun off Federal and the other shooting sports manufacturers into Vista Outdoors, I don't know where other things will land. I assume ATK Orbital (the other half of the spin-off) is still running Lake City, as their contract would still be in force.

Federal 5.56 brass, AFAICT, uses 70:30 brass made to military specs in terms of hardness. I think the NATO compatibility requirements insist on that. The STANAG drawings have cross-sections that include brass hardness points in sectioned cases, though they may be suggested rather than final values. I'll have to look. The Federal 5.56 brass I have all seems as hard as LC headstamp brass. I don't know about the hardness of Mk.316, m.0 7.62 brass, as ATK's presentation on that ammunition said Federal expertise in making match brass was applied to designing it. I don't have any.

The computer type supplies are all switching supplies these days. Transformers have gradually faded. Too heavy and expensive. The problem with inrush to a transformer with a low impedance load is due to switching them on when the line voltage is at zero crossing and doesn't cause self-induction in the winding immediately. So the darn thing looks like a low value resistor, briefly, and that can sure pop breakers. We had that problem with 3 kW transformers feeding large heat sealers where I worked at one time. I fixed it by designing a zero-crossing detector that tripped a quarter cycle delay before an SCR set switched the primary to the line. That way the transformer only got power connected when the voltage was peaking, which corresponds to the current zero point. I can reconstruct the schematic if you are interested; PM me to let me know.
 
I don't know the specifics,
ATK took over the Lake City plant from Olin-Winchester.
I know that for certain.
Previous military career allows me access to some of the facilities once in a while. and other than the buildings being in more or less the same place, you wouldn't recognize it...

In 2009 they did a MAJOR overhaul at Lake City, I actually tried to buy some die machines when the old ones were scrapped,
The government would rather melt them into slag than let someone get some use from them...

In 2012 the 'Standard' for military/government cartridges was changed to what ATK was producing at the time.
The excuse was 'Weight Reduction' while maintaining operational quality,
AND,
The 'Lead Free' craze has hit the military/government...
ATK 'Says' they can make a better, lighter (Up to 12% reduction in weight) lead free cartridge, and they have the government in their pocket, so they got the contracts.

That's about all I know...

If I hadn't been having lunch (and trying to sneak a cigarette) right beside the truck dock at Federal I wouldn't have known about General Dynamics unloading 'Federal' head stamped 5.56mm & 7.62mm brass on the docks in bulk bins.

One thing about cheap power supplies, they 'Ramp Up' to full output!
'Soft Start' is built in if you switch the power supply instead of the induction unit!
It's a 'Hack', but it works quite well!

Even if you have full power all the time, 'Soft Start' units (for things like amplifiers) are dirt cheap and handle up to 2,500 watts.
Another 'Hack' when you just want to solve a little problems and not re-invent the wheel...
Cheap at under $5 each!

I would be VERY much interested in what you have, I'm always ready to learn something new from a professional!
As you can tell, I'm hardly a 'Professional' at this stuff, mostly I just 'Hack' the parts I can commonly find.
 
You must log in or register to reply here.
Back
Top