Alternative to clay when producing hamon?

A

AndrosCreations

Joined
Dec 1, 2010
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Greetings... I wonder if it would work to harden the whole blade and then suspend the edge in water while torching the spine?

If engraving was desired on the spine, it would need to be reasonably annealed.

Think it would work?
 
The process your describing is a method of differential tempering. From my own experience and the advice of others, you wont produce a hardening line using this method.
When differential tempering, you only want to make the spine a little less hard than the edge. This makes the blade tougher overall but still maintains the hardness at the edge for cutting performance. If the spine is too soft or the hard edge is not high enough on the blade, the blade will take a set when enough side force is applied.

If you don't want to use clay for whatever reason, you can achieve a hardening line by edge quenching, or by just bringing the edge up to temp before quenching.
You won't see the nice shapes or the activity that can be achieved using clay, but you can get a line to develope using these methods
 
A good way is to go for an "auto-hamon" which is achieved without clay. You need shallow hardening steel such as W2 or 1095, and it helps if the spine is a good bit thicker than the edge going into the quench- a full flat or saber grind is best. Basically, you go into your Parks 50 or brine, and quench only for about a short 3 count, pull it out for a few seconds, then back in, then maybe out again at about 400 degrees and let air cool. If using oil, watch out for the flash that will happen.
This helps your steel get under the pearlite nose in the thin section, but not in the thick section. You should be at the very low end of austenitizing temperature for your steel, say 1450 or even a bit lower for W2. The interrupting can really help the steel deal with the shock of the quench, for water or brine.
Guys like Nick Wheeler have gotten some truly insane hamon with this method.
 
Its funny you mention that. its the process we use now for hamons..I find you get much more activity like this..Though to be honest we don't do many hamons because of the ridiculous amount of work involved in polishing a hamon the right way..
You know we make a lot of striker knives from old thick files for the bushcraft folk..The steel is 1.25% carbon and very low alloy,very little mn, only about .025-.030...When we heat treat them because they have such a thick spine(around 1/4") ground full flat down to a thin edge those things throw the most amazing hamon..Im serious, it easily rivals W2 for hamon activity..Of course its never polished because of the kind of knife it is but its very easy to see even at low grits..Crazy ammounts of "cloudy" activity.
 
Andros,

Why not do your engraving on the blade before you harden it? If done along the spine, a coating of anti-scale compound may protect it during the quench.
 
If you do that and get flame up, you may want to adjust your tempering temperature as the flaming may cause some degree of "auto temper" I had one customer who bought two W2 kitchen knives from me, one hardened straight up and one with a hamon that I pulled out too early and it flamed up. He said that the hamon blade felt a bit "softer" on the stones even though it still worked well.
Kentucky said:
Its funny you mention that. its the process we use now for hamons..I find you get much more activity like this..Though to be honest we don't do many hamons because of the ridiculous amount of work involved in polishing a hamon the right way..
You know we make a lot of striker knives from old thick files for the bushcraft folk..The steel is 1.25% carbon and very low alloy,very little mn, only about .025-.030...When we heat treat them because they have such a thick spine(around 1/4") ground full flat down to a thin edge those things throw the most amazing hamon..Im serious, it easily rivals W2 for hamon activity..Of course its never polished because of the kind of knife it is but its very easy to see even at low grits..Crazy ammounts of "cloudy" activity.
Click to expand...
 
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