Aldo's W-2 Hamon problem

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Feb 24, 2000
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I decided to make a sort of large competition knife out of Aldo's W-2 steel. I started with 1/4"x2" and used the stock removal method.
I have used a lot of Aldo's W-2 steel in 1/8" size and have gotten good hamons.
j8yqpj9.jpg


I have used a torch to heat treat the 1/8" steel, but this knife had a 13 1/2" blade which I felt was too large for the torch to heat so I used my Paragon oven.

My procedure was,
1650 for 20 minutes, then when black quench in Park's 50
1550 for ten minutes, quench in Park's 50 when black.
1450 "
1350 "
1250 "
Then I put Rutlands clay on the blade, let it dry overnight, heated to 1460 for 10 minutes and quenched in Park's 50.
Then I tempered twice two hours at 424 degrees.

When I etched in FeCl and gave a very brief polish, this was the result. The temper line did not come close to how it was clayed. It was clayed exactly the same on both sides of the blade.
nYy3btk.jpg

ajJ2cUI.jpg


The blue tape shows where the clay was.

Those of you with experience with Aldo's W-2 steel. Would you suggest I change the heat treat formula?
When I have heat treated the 1/8" steel I have put a light coat of Brownells ATP-641 over the whole blade. I did not do this with the 1/4" blade.

Any suggestions as to why the hamon turned out the way it did?
 
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How thick was the clay? Can you thermal cycle and try again? Interested in answers also.
 

kuraki

Fimbulvetr Knifeworks
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Tom it looks to me like the thickest part of the blade never got up to temperature.

How did you quench when hardening? Any agitation? Interruption? How long?
 

Josh Rider

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How fast did you get it from kiln to oil?
How thick was the Rutlands?
 
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Thanks for the interest and questions. I will try to answer them.
1. From kiln to oil would be maybe one second. All I had to do was pull the blade out of the Paragon, turn around and quench in the oil. The oil is right next to the Paragon.
2. The rutlands was maybe 1/8" to 3/16" thick
3. I agitated the blade up and down and left it in maybe 20 seconds.
4. The blade is finished, so I can't re-quench.

Any thoughts, suggestions, etc. would be appreciated. For those of you that use Aldo's W-2 steel what heat treat process do you use?
 
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A few theories... your blade was thicker than your normal hamon stock, so the clay layout you normally use may have been too thick... this in combination with the greater thermal mass of the thicker blade plus the pretty thick clay, may have retarded the quench down past your clay line. Often with thicker blades, especially with a flat or saber/flat grind, geometry is really enough for differential hardening in oil... which of course is why "autohamon" works. Clay can be applied quite thin, think more like 1/16", and acts as more of a suggestion to shape the habuchi/ashi rather than have it random.
Also, it appears you took thorough steps, thermally speaking, to reduce grain size... it could be that you got your steel to be more shallow-hardening than you bargained for, which in combination with your geometry and clay thickness, could certainly have resulted in such a low line.
If you crank your torch, and wrap a wet rag around the front of the handle, maybe you could re-quench that with the handle on... or, I've had success in the past with freezing the knife, then carefully prying the edges of the scales up starting with razor blades, and pushing the pins out. The freeze will weaken epoxy a little. If you're careful you could reinstall those scales and even pins...
 

kuraki

Fimbulvetr Knifeworks
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1650, 1550, 1450x2 no quenching just air cool.
Aus at 1460
Quench in p50 thicker knives uninterrupted but smaller ones with interruption.

I think Salem nailed it with hardenability. The only thing that quenched fast enough was the thinnest portion.
 

Josh Rider

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I’d buy some satanite too. I haven’t used rutlands but satanite is great because you can thin it down for ashi and thicken it up for your hamon fingers.
 
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I use aldos w2 pretty regularly with Rutlands, and have done 1/4 inch a handful of times with no issue. thickness of it i think your going waaaay too much. Ill put down anywhere from 1/16th to at the very max 1/8th. Also, try diluting it some. I do 5% water to mine, and it has made getting the resulting hamon i want much easier. Lisch taught me the trick a few years back and id never do it any other way now.
 

A.McPherson

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So if you have reduced the hardenability to the point that it won’t harden, can you just do a long high temp soak to reset things or are you just kinda hosed?
 
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So if you have reduced the hardenability to the point that it won’t harden, can you just do a long high temp soak to reset things or are you just kinda hosed?
You could give it a high heat and put the carbon back into play. Reset your grain by correct thermal cycling.
I sort of change my previous answer, though. If he's quenching from black there really isn't much phase change occurring. W2 is pretty simple - and responds quickly. Don's right - too much fiddling around.
In the words of Jimmy Fikes - get it hot and quench it in something wet.
 
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Thanks everyone for your suggestions. I don't think I will try to do anything with the knife I made. I'll just keep it for a wall hanger.
I started on another knife this morning and should have it ready for heat treat this afternoon.

I'll use 1650, 1550, 1450x2, then 1460 and quench.
I'll also put the clay on no thicker than 1/16".

Something I have noticed is that I don't ever see the hamon till I have hand sanded to like 800 grit. I know others see it much sooner. Nick, nice to see you back again. I'll try your suggestion of the flash light in a dark room. It would be very helpful to see the hamon or lack there of before I grind the blade too thin to re- do it.
Larrin, I'll try 422 for the temper this time.
:)

Thanks again and if you have anymore suggestions I would like to hear them.
 

Willie71

Warren J. Krywko. Part Time Knifemaker
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You could give it a high heat and put the carbon back into play. Reset your grain by correct thermal cycling.
I sort of change my previous answer, though. If he's quenching from black there really isn't much phase change occurring. W2 is pretty simple - and responds quickly. Don's right - too much fiddling around.
In the words of Jimmy Fikes - get it hot and quench it in something wet.


With Aldo’s, some won’t harden unless normalized and cycled, just like his 52100.
 

jdm61

itinerant metal pounder
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I you can't see a vague outline of the hamon right out of the quench, it probably isn't going to look very good when finished.
 
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