HT 1095 for hamon

M

mantiss

Joined
Oct 30, 2017
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Good morning fellow knife nuts, this is my first post, and I want to start off by saying that this forum is an awesome resource for makers, new and old
I've been lurking here, absorbing knowledge while I make knives, and I truly can't thank all of you enough. My question is: do you need to soak a clay coated 1095 blade at temp (per Larrin's formula), or just go to non magnetic, then quench? Will soaking (for 10 min?) reduce hamon activity? It would seem that long at temp would leave a blade through heated. Any guidance would be greatly appreciated, thanks in advance.
 
mantiss said:
Good morning fellow knife nuts, this is my first post, and I want to start off by saying that this forum is an awesome resource for makers, new and old
I've been lurking here, absorbing knowledge while I make knives, and I truly can't thank all of you enough. My question is: do you need to soak a clay coated 1095 blade at temp (per Larrin's formula), or just go to non magnetic, then quench? Will soaking (for 10 min?) reduce hamon activity? It would seem that long at temp would leave a blade through heated. Any guidance would be greatly appreciated, thanks in advance.
Click to expand...
Even if the steel under the thicker clay along the spine is up to temp the clay will slow the quench in that area, I know I’ve seen people recommend hardening in a forge or torch to have better hamon activity, you could always start with the lowest temp and time for hardening then increase as needed to achieve the hamon you want, with W2 for example I place the blades in my kiln and when the temp rebounds I start a 10 minute timer, at 1475 the hamon is right at the clay line but with reduced activity, at 1465 it’s very close to the clay line with better activity, at 1450 it’s below the clay line with the best activity but a bit lower on the blade than I’d like so I settle for 1465. I’d try this test on some sample knives of the same shape/size and pre grind, try to clay them all the same and you’ll be able to see what you like best.
 
Thank you for the advice Josh, I appreciate it! I'm working with a forge for HT, so I know I'm limited in really getting things dialed in. My next piece of equipment will be an oven- hopefully not too far down the road..
 
Joshua Fisher said:
Even if the steel under the thicker clay along the spine is up to temp the clay will slow the quench in that area, I know I’ve seen people recommend hardening in a forge or torch to have better hamon activity, you could always start with the lowest temp and time for hardening then increase as needed to achieve the hamon you want, with W2 for example I place the blades in my kiln and when the temp rebounds I start a 10 minute timer, at 1475 the hamon is right at the clay line but with reduced activity, at 1465 it’s very close to the clay line with better activity, at 1450 it’s below the clay line with the best activity but a bit lower on the blade than I’d like so I settle for 1465. I’d try this test on some sample knives of the same shape/size and pre grind, try to clay them all the same and you’ll be able to see what you like best.
Click to expand...
What if you go 1450 for best activity and move the clay line up a little?
 
Richard338 said:
What if you go 1450 for best activity and move the clay line up a little?
Click to expand...
the first blade is 1465 and the second was 1450, I actually think the 1465 looks a bit better but the main reason is just that it’s more consistent to the clay line, I could move the clay up but I already only cover the top 1/3-1/2 the blade so I wouldn’t have much clay on the spine.
0847C02C-EA41-4744-8888-B6753C2EEACF.jpeg7A9FF4FF-97D7-4EB3-806F-E21D7F1619F9.jpeg
 
Joshua Fisher said:
the first blade is 1465 and the second was 1450, I actually think the 1465 looks a bit better but the main reason is just that it’s more consistent to the clay line, I could move the clay up but I already only cover the top 1/3-1/2 the blade so I wouldn’t have much clay on the spine.
View attachment 1677403View attachment 1677404
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Nicely done. Good control of the heat there!
 
To get the most out of 1095 you need good heat control. Cross section should also be mentioned. A blade that is 1/4" thick at the spine and ground thin before heat treatment and an unground blade blank (for a kitchen knife, etc.) that is a constant 1/8 will react differently. If there is a significant difference in thickness across the blade the results will be more pronounced because the spine will cool much slower than the edge. The effect may be less if you leave your bevels on the thick side before heat treatment. The thickness off the clay, the heat treatment, the type and strength of etchant and etch times, polishing techniques all affect the outcome. It is as much art as science.

This is a forged 1095 blade I recently finished. The heat treat I used is not important because everyone's equipment is different. But it shows a certain type of cross section, how the clay was applied and the resulting outcome. The clay was Rutland's Black furnace cement.

The clay
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Post heat treat @220X
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@2500X
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After a few dips
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Done
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