What happened to my hamon

joesouth

joesouth

Joined
Jun 16, 2006
Messages
74
Well guys I thought I was confident enough in my skills that I would try to attempt a hamon line with clay. Always surprises though. I have attached a photo for any suggestions. The blade is hand forged 1095 1/4 thick, 7" blade, the red line shows where I placed the clay. I got a great line but I think it is way to close to the edge, less than 1/4" at the choil. My question is why did the hamon move so low. i used a trns. fluid and hydraulic oil quench heated to 120 deg. and dipped the entire blade edge first. Did the blade cool to fast or could it be something else. Any suggestions would be greately appreciated.
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Oil to cool. Go up to 150 and you really should use real heat treating oil. Makes a world of differance.
 
1095 needs to go in the quench very fast. Think thats what your problem is. Need to get it out of the oven and into the quench in 1/2 a second or less.
 
Thanks guys, kinda thought that was the problem. I'll chalk this up as a learning lesson and order some real quenchant
 
Blade probably wasn't heated all the way through. If you're using the right temps, let the blade soak up those rays. :)
 
The oil was too slow for the steel to harden more than the edge. The 120F would have been fine if you were using Heatbath/Parks #50 or any of the other fast oils.
I put my clay much farther down the blade,too. As said, soak the blade to assure complete and even heating. Another problem may have been the blade not being hot enough. How did you control the temp, and what temp did you use?
Stacy
 
bladsmth said:
The oil was too slow for the steel to harden more than the edge. The 120F would have been fine if you were using Heatbath/Parks #50 or any of the other fast oils.
I put my clay much farther down the blade,too. As said, soak the blade to assure complete and even heating. Another problem may have been the blade not being hot enough. How did you control the temp, and what temp did you use?
Stacy
Click to expand...

Room temp seems to work fine with #50...........well, Florida garage room temp anyway:D I am using a Home Depot special 30 quart turkey fryer and 5 gallons of # 50 for a quench setup and I haven't even set up the burner so far. I suspect that I will have to when the weather gets cool. For slower steels, I have a large roasting pan with 3 gallons of Tough Quench.
 
I use a homemade forced air propane and heat it up till no-magnetic and hold it there for appr. 15 min. and quench. I only have to go a few inches to the oil from the forge. might I add that this is the way I do all my blades without the clay and they work out just fine. Guess I have some more learning to do. O.K. though thats the funnest part of this hobbie
 
I agree with too much clay..i think of hamon work as pushing around heat. I understand it as the clay gets up to critical right along with the blade, then serves as both a "mask" preventing the oil from leeching heat away from those areas, and also having a thermal mass that requires longer to cool, not allowing that area to harden.

If your clay is too think that extra masking and heat will "push" the hamon line down. I think of the hamon line as a thunderstorm where a cold front (the steel you are trying to harden and is cooling rapidly in the oil) and a hot front (the hot spine, with added thermal mass of clay) meet. if you have too much heat pushing from the spine, the line goes low....if you have too little clay or too little heat on the spine, more of the blade with harden higher up, pushing the line higher.

This isnt scientific, but seems to make sense and experiements i have done with clay seems to support the idea, even if the logic isnt scientifically sound. You can't "paint" a hamon with clay...you need to "massage" a hamon by noticing how clay pushes around that transition line. Heres an example of a bit too much clay and a lot of action showing in the inbetween areas. I got lucky and ended up with an absurdly active hamon, but was dangerously close to needing to re-ht as the transition line was a bit too close to the cutting edge for my likes.

Way too much clay:
before.jpg


Result:
hamon3.jpg
 
Ive never been able to get a subtle double and triple layer hamon like that since. It has a main transition line, a secondary, and the multiple layers above that. Those layers were most visible in the knife's pristine state, but the finish was so delicate that most were not nearly as visible in its final form.
 
Thanks Don and Dave, never thought of that, good idea,gonna try that tonight. Tried to get some fast quench from Ellis custom but their inventory is out and they don't know when more is coming in.
 
You do know you can heat treat that blade again, right? If it is now too thin, you may have to grind a bit of the edge off.
 
Joe

If you are in a hurry you can get Fast Quench 9-11 second oil from McMaster Carr online. Cost me $75 delivered. I like The parks better, gives more activity in the hamon. Parks is a 7-9 second quench. If you want to get going really fast then you could try brine. Put enough rock salt in a 5 gallon bucket of water (preferably distilled or rain water) to float a potato. The only problem with brine is you may have cracking problems. With 1095 it should not be as bad as W-2 though. Take a look at Don Fogg's website. He uses 1095 and gets great hamons using rainwater. If you put a thin wash of clay over the entire blade it gives the same effect of quenching in brine. Good luck and I agree this part can be the most fun but also the most frustrating.

Chuck
 
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