Induction Annealing

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Ken73
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Induction Annealing

Post by Ken73 »

Any reason one of these wouldn't do the trick?

http://www.ebay.com/itm/Dental-heater-H ... 705wt_1163
pgg
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Re: Induction Annealing

Post by pgg »

It looks like an infrared heater for melting wax. I'd guess no.
Ken73
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Re: Induction Annealing

Post by Ken73 »

Says it's an induction heater for heating the knife, not the wax?
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Magos_Mal
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Re: Induction Annealing

Post by Magos_Mal »

Dental wax tools are usually not heated to the 600-700 degrees where brass anneals.

While this might work, I'd be suspect of its construction and if the longer time needed to anneal the brass would cause too much resistance in the induction coil and burn out the machine.
-Exterminatus-
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Wyldman
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Re: Induction Annealing

Post by Wyldman »

I got an induction heater to anneal my brass. I got this one: http://www.ebay.com/itm/Induction-Innov ... 35b85a0fe3.

I got mine for $325, but it took some shopping and patience to find one that cheap. Mark the case neck with a 750 degree Tempil Stick and stick it into the coil until it indicates, then toss it into a can of water. It works great for me, so far.
Notar
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Re: Induction Annealing

Post by Notar »

Induction at some point might be the preferred method for annealing. No flame, computer controlled, repeatability, etc. I use Flame, but after seeing a few induction units pumping out good annealed Brass, I'd jump to that ship.
RocketmanOU
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Re: Induction Annealing

Post by RocketmanOU »

NO. In order to prevent the body and head of the case from heating too much (anything beyond about 475°) while heating the neck to 700°+, you have to get the heat into the case very quickly, as the copper will conduct the heat very quickly. If you're using an inductor, you'll need a very high power output - FAR higher than 130 watts. I would stick with flame, but that's just me.

To show you what I mean, I ran a quick FEA simulation on a 300 blk case, using a full 130 watt input. The temperature change down the case wall is due to nothing but direct conduction of the heat through the case itself. Any part of the case that changes color is unacceptably hot, and full annealing only takes place on the parts that reach a full red color. The video is in realtime.

http://youtu.be/RbhrdyrfEDE

Edit: bumping up to 500 watts appears to just about do it, if all the wattage could be pumped into the case neck area only, and the case was very quickly cooled afterwards. It would still take about 9-10 seconds per case, but temperature penetration down the case wall would be less because of the quicker transfer of heat.
Notar
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Re: Induction Annealing

Post by Notar »

Cool sim, can you run one with flame, and a 5-6 sec duration for comparison. 500 W, holy shizz, maybe flame will last a long time for case annealing.
Ken73
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Re: Induction Annealing

Post by Ken73 »

Thanks guys for the reply; I figured folks here would have the wisdom to keep me from wasting my hard-earned dollars! :lol:

I'll start looking into the different methods of doing it with flame; I'm just not keen on spending $500+ for either method personally. I've seen the kit on Midway that seems reasonable?
RocketmanOU
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Re: Induction Annealing

Post by RocketmanOU »

Ken73 wrote:Thanks guys for the reply; I figured folks here would have the wisdom to keep me from wasting my hard-earned dollars! :lol:

I'll start looking into the different methods of doing it with flame; I'm just not keen on spending $500+ for either method personally. I've seen the kit on Midway that seems reasonable?
I use the Hornady kit from midway for about $50. Works well, and is easy and safe.
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