Quench to temper delay

steveo83

steveo83

Joined
Aug 4, 2008
Messages
88
Hi All,
I am ordering in an Evenheat oven from the US to try my hand at heat treating. i'm going to start with some 1095 steel that I have and was wondering how people go about using the same oven for tempering?

Do those who use the Evenheat for tempering just wait until the oven has cooled enough after the HT before putting their blade back in for the temper (and if so, how long does this likely take?) or is it that the Evenheat is used for the heat treat, and a second pre-heated oven is used for the temper?

I am assuming that I need to go from the quench to the temper as soon as possible but am worried that trying to use the same oven for both HT and temper might cause timing problems.

Can anyone offer any suggestions?

Cheers
Steve
 
I use a toaster oven for an initial temper [usually lower than 'ideal']. Then do a final temper in the Evenheat. It takes hours to cool from 1500 to 400 [or the chosen range]. I do'nt like to leave 1095 untempered that long.
 
I say temper your knives intially with your toaster oven like Dewey said, perhaps a little lower than your final temper as toasters ovens are well...not that accurate. You could even install a pid and a thermocouple to read the temperature of the toaster oven for cheap for the first temper or get crazy and install an SSR to control the toaster oven ! wait till the next day and start with your at room temperature newly purchased Evenheat kiln ! I have two of them and they are great !
 
Again like Robert says the toaster oven is the go .I finde that after the 2 hour temper in the toaster oven the Evenheat has usually got down to the 400 f mark ready for the second temper.I use a hospital grade thermometer i got from a catering supply store and i checked it against the Evenheat, only 20 f out, this is put in the toster oven to moniter the temp.So far out of 30 blades i have had tested none have been more than .8 of a rc point either side of 60 so i can't fault the Evenheat oven.
 
Put a brick in the toaster oven to reduce temperature fluctuations.
 
When not using two HT ovens, this is how I do it:
While the HT oven is soaking the blade, I turn on the kitchen oven at 350F. After quench, I clean off the blade and immediately place it in the kitchen oven for two hours. After this first temper, I check the hardness,and set the HT oven ( which has usually cooled by now) to the desired temper setting.

With steels like 1095, getting from quench to temper should be fairly soon.

Stacy
 
I now have three EvenHeats on the go, but used to do the initial "flash temper" in the toaster oven or kitchen oven as well. I would set it much lower than specs - 100 degrees or so lower - just to take the stress off after hardening - then do two full tempers in the kiln when it cooled down. Watch out for cooling temps. If the door is open at high temps, it is hard on the coils - and at low temps, it can appear low enough, but the brick mass is still hot enough that temp will climb quickly over setting just from stored heat.

Rob!
 
Since my shop is several miles away from my house, I don't feel comfortable leaving the Evenheat or especially my homebuilt on without supervision. So I have my wife pre-heat the kitchen oven for me and perform both tempers in the kitchen oven. I let the oven heat soak for at least 45 minutes so it is more stable, and I use a cookie sheet or foil to shield the elements from my knife. I also hand the knife in the oven with a piece of wire so it's not laying on its side. I use two seperate oven thermometers to verify the temperature as my kitchen oven can be as much as 25 degrees off.

Another thing I don't like to do is leave the heat treating oven doors open while it's cooling down. I would think you would burn through elements faster that way, though it would cool down faster.

--nathan
 
Thanks guys for the warm welcome and great info - exactly what I was hoping to learn.

I'll look around for a small toaster oven to run the initial temper (at 300 - 350f). Only problem is, this limits me to very small <12" blades I'm guessing? Not a problem for now though I guess.

So it seems the best way is to leave the Evenheat closed during the cool down, but will it cool down enough within 2 - 4 hrs to be usable for the final temper or will keeping the doors closed write it off until the following day? Even so, waiting 12hrs or so after an initial temper at 300 - 350f shouldn't be a problem should it?

On another note - I had my first go at soldering yesterday. Thanks to all the tutorials on this site it went quite well. Next time will be better.

Cheers
Steve
 
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