Clay heat treat problem

[RHaskins]

Tried to use clay (satanite) for first time on 0-1 to get a wavy pattern. Heated, than edge quenched. When I started to etch no wavy pattern just normal edge quench line visible.
What did I do wrong? Was clay not thick enough or was it something else? :confused:

Hope some one can shed light.
-Randy

[HellForged]

I would venture to say that the problem is the edge quench.... When clay treating the clay acts as an insulator, retaining the heat. You should full quench the blade and let the clay take care of the "edge quench". I've never done it before so take what I say with a grain of salt but I think that will be the problem. Hope it helps.

~Matthew

[tonn]

Randy!
With some steels hamon will follow a clay coating closely, with some not. Here may be a reason.
Usually a deep hardening steels does not make a good hamon.

[AcridSaint]

I think it's a little of what both guys said... you don't want to edge quench a clay coated piece, the clay is what keeps the steel from hardening so you don't have to edge quench. All of the O-1 clay treated pieces I've seen had a really subtle hamon. I don't know how much polishing it takes to bring it out, but it always seems to be really faint to me.

[ekillian]

I have trial and errored many times with the clay tempering. DO NOT OVERHEAT DURING TEMPERING( It seems to remove the temper line) Also, everyone else is right, fully submerse the blade. Acid etch and Polishing is the key to a really standout temper line. Do not let the acid etch for more than a few seconds (25 to 30) and make sure you neutralize the acid quickly (ammonia) then lightly polish and etch again until you get it where you want it.(6 to ? times)

[RHaskins]

Thanks for the help everyone, so next time I will quench the whole blade.
Also if someone can give quick answer on this when you acid etch (because I have read both), do you etch whole blade or just hamon?

Thanks again
-Randy

[ekillian]

All of the blade but no need to do the tang.

[RHaskins]

Ok than, thanks for the help I have to get my next knife going so I can put this into practice.

-Randy

[Jason Cutter]

While I am a very keen user of the clay backed hardening technique, much of my understanding of the subtleties of technique have come from discussing it with other makers who use it. 20 heads are better than 1 !!

Firstly, O1 is (as mentioned) a deeper hardening steel than the simpler 10-xx or W1, W2 steels. I like 1095 and 1084. O1 will simply not manifest as clear a hamon as theose other steels. But it can be done. If you get a nice hamon on O1, it is also appear more clearly if you give it a light etch in ferric chloride.

Secondly, As someone else (Hellforged) has mentioned, don't attempt a "edge" quench when using clay, uinless you are after a very specific effect - it has a higher likelihood of failure than other techniques. Its easier, and more consistent to plunge the entire blade.

Thirdly, make sure that the heat is slow as you get the blade up to quenching temp. The reason ? The clay acts as a heat resist AND a quench resist. Initially, it will take much longer to heat the blade up to the hardening temp. If you rush it, you will likely overheat the edge and cause excessive grain growth. If you don't heat it up enough, the area under the clay will stay cool, and suck the heat out of the edge as you go from forge / oven to quench. So the hardened area will be lower and thinner than expected. So GO SLOW AND GET IT HOT. You should be able to see the area under the clay as it goes a bright red - the clay becomes transluscent. If you can't see it, its not hot enough.

Hope this makes sense and helps a little. Jason.

[RHaskins]

Sure does make sense Jason. Thanks for all the suggestions, I know 0-1 is not the best selection for getting a strong hamon but I guess I'm just very stubborn and determined to keep trying. Any way if I ever get some what of a good looking hamon I'll post it for comments. Thanks again for the help.

-Randy