using clay in reverse to differential temper??

V

VII Blades

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Dec 13, 2011
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I was wondering if anyone has used clay on the edge portion of a blade to keep it cool while using a torch to bring the back of the blade to blue?? I was going to try it, but was wondering if anyone has done it this way?? My thought was to map gas torch temper to straw color twice, then coat the edge in a reverse Hamon of sorts. then while the clay is still wet and able to suck the heat away I would heat the back of the blade to blue.

oh yeah, I am doing it this way because it is on smaller blades
 
From what I've read, the usual method is a tray of water with the portion of the blade to be cooled in the water and the heat applied to the area above the water.
I'm not sure how well the clay would work in this case.
 
Remyrw said:
From what I've read, the usual method is a tray of water with the portion of the blade to be cooled in the water and the heat applied to the area above the water.
Click to expand...

My blades are quite shapely and if it does leave a temper line I would prefer the line to meet the curvature of the blade, I thought I could do that by using clay
 
Well, hopefully someone has some good ideas for ya. Maybe it would work if the heat was applied quickly enough that it doesn't spread down the blade under the clay. I don't think the clay will hold up very long in terms of keeping the blade cool, the reason for the clay is generally to reflect heat away from the blade, not absorb it. The solution might be some form of gel though, I know there are some out there for welding and such where you need to protect things from the intense heat being applied.
 
I guess I will give it a try, the worst that could happen is I have to re-heat and quench the blade.
 
Actually, the clay typically holds heat and slows down the cooling of the clayed portion of the blade. Wet clay may work better, but it's a pretty good insulator as opposed to conductor of heat.

The other issue I see is with time at temperature. Tempering is a process that involves both. Typical tempering cycles run for 1-2 hours depending on the steel. With more simple steels, a reduced time can work out ok, but I think you'd still need to hold temperature for a while to get a true temper. I'm not sure if there's any good way to get a decorative/designed temper line. With practice, on the other hand, you could clay quench your blades and work on guiding the hamon via clay and heat to get in the ballpark of where you want it.

--nathan
 
silver_pilate said:
Actually, the clay typically holds heat and slows down the cooling of the clayed portion of the blade. Wet clay may work better, but it's a pretty good insulator as opposed to conductor of heat.

The other issue I see is with time at temperature. Tempering is a process that involves both. Typical tempering cycles run for 1-2 hours depending on the steel. With more simple steels, a reduced time can work out ok, but I think you'd still need to hold temperature for a while to get a true temper. I'm not sure if there's any good way to get a decorative/designed temper line. With practice, on the other hand, you could clay quench your blades and work on guiding the hamon via clay and heat to get in the ballpark of where you want it.

--nathan
Click to expand...

i wanted an easyier way than traditional clay methods. but if there were an easier way people would use it. I am using old files that have been hammer forged. I ended up edge quenching, we will se how they come out.
 
The clay is not to mask the blade from heat but the complete opposite. It retains heat and masks the blade from the oil/cooling.

You could possibly experiment using aluminum plates, though..they'd likely suck the heat away quickly like they do in a plate quench.

Is your goal the tempering colors? There's normally no such thing as a tempering line, just a hard/soft steel transition line.
 
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