Setting up new oven

Ben Sellers

Well-Known Member
#1
I bought a new Evenheat KH18 with Genesis controller, solid state electronics and Bill Burke modification that should be delivered within a few weeks. My plan is to build a table to put it on that has a top layer of cement board. I'll also line part of the garage wall nearest the oven with the cement board.

I'm going to work with 1095 first. My plan is to test coupons 2 inches long starting with the schedule for 1095 on Kevin Cashen's website. I'll vary the temperature by 15 degrees each way and see how it snaps and what the grain size look like. I will be quenching in unheated parks 50.

I do have foil. Should I wrap all steels that go in the oven in foil? Is that a reasonable way to get started with a ht oven?
 

scott.livesey

Dealer - Purveyor
#2
first thing I would do is check accuracy and location of the kiln thermocouples. how far away is the thermocouple from where the knife will sit. is it possible to place a second thermocouple next to where the blade will sit? see how much it differs from the kiln thermocouple. second would be to have 2 or 3 thermocouples with seperate displays in addition to kiln thermocouple set up within an inch of each other. I did that with one of my kiln and found total difference of 15*F, close enough for carbon steel. If you keep temperature below 1500*F, I doubt you will see any differences in the samples. foil is great for air hardening steel,but I don't think you can unwrap and quench quick enough for 1095 or other steels that need fast oil.
 

Ben Sellers

Well-Known Member
#3
Thank Scott. I will have to get my hands on the oven to see where I can add thermocouple. My starting temp will be 1475°, so below 1500°. I was concerned about the unwrapping time with the oil on a fast quench. I bought the foil for some aebl that I have plans for, but the started wondering if I needed to use that on carbon steels too.

Thanks again.
 

ARCustomKnives

Well-Known Member
#4
I personally wouldn't use SS foil for anything but air hardening steels. The reason it's even used with air hardening steels is because of the excessive oxidation/scaling that you'll see due to the higher temps and longer soak times needed to heat treat it.

1095 only needs to hit around 1475F for a few minutes, which, while hot enough to promote scaling, is not nearly as bad as 1900+ that most air hardening steels need to reach. Also, 1095 has a relatively short window of time that it can be removed from critical temp before you need to quench, and there's almost no way you would have time to cut off a foil envelope in order to get a good quech from a fast oil or brine solution.

Now, I should probably add that I have recently seen claims of makers getting good results from plate quenching steels like 1095, but outside of the pictures and hardness test "claims", the evidence, or discussion of the exact process used has been somewhat lacking. I'm not saying it's impossible, but I'd really like to see more info and testing concerning these claims. As for me, I always heat to 1475, let it soak at temp for about 5 minutes (or a little longer based on blade size), and then quench in P50 that I've heated to about 80 or 100F. After that, I'll typically temper around 375 to 450 depending on the type of knife, geometry etc... (usually 400F for the average knife), and I've had good success.
 
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