Lil' (big) something I just started...questions on clay coating

Did a bit more hand sanding and etch tests today after doing my brass rod test and a flex test....

The wild lines above are not as defined in the main transition line. That line runs closer to the edge, wavy, but not with the wild swirls that you see above. I do, however, see some activity above that line, so we will see as final grinding and polish occur.

The hamon is low, almost to a point it worries me. It is 90% fine but one wave comes within about 1/4" of the edge. Im going to leave it and finish and see what happens.

I think I have lots more to learn and experiment with here....I think speed of the quench is really important, especially with the sub-1-second curve for 1095. In hindsight, I would guess my clay was too thick, adding a ton of mass to the heat coming down from the spine upon quench. Since that hardending happened in the first second to build the line (correct me if I am wrong on that), I think I had too much heat in the spine to get the steel down below the nose up in my clay gaps. After looking at some clay patterns on swords, i have a better idea of what I should be doing.

More experiments to come in my future!
 
LongRifle said:
I'm going to back up my man Nick. Hamons are determined by time and temperature, definitely not the clay.

It took me a long time and many, many failed attempts to figure out that I could paint a Picasso on the blade and still end up with a straight hamon.

My best advice is to omit the clay entirely. Stick with hardening lines for the time being and figure out when the blade goes into solution, what temperature, time, and type of quench. Once you have a strong understanding of how ht'ing actually works, then move on to the clay. Otherwise, you'll be disappointed every time and will not make the leaps and bounds of improvement.

I try with each new knife to be Yoshihara, it hasn't happened for me yet, and probably won't for a very long time :). Hamon is a difficult, up hill battle; you'll also need to learn polishing and etching. Once you get hamons nailed I think you'll be like me and shudder when people refer to "hardening lines" as "hamons" :) ;) :p :cool:. That's tongue in cheek, but when I think of all the hard work, experiments, failed attempts, and frustration I see a difference between "hamon" and "hardening line" :) and you will too.

Good luck, and keep us posted, you'll nail it. I think the blade you've got there rocks, and the ironwood is fantastic!

Matt
Click to expand...
Hi Matt, Would you clarify that first statement about it being time and temp, not the clay. I understand all heat treating processes are a matter of using a given temperture over a specified time. I see it as, without the clay you would not be controlling the time and temp in those specific areas coated by the clay.
I coat the clay with borax before the quench to help delineate the hardening line/ hamon. I realize you can get great lines with out the clay so why clay? Fred
 
Without using a torch or clay, how would one create a wavy, exxagerated hamon? I would think you'd need uneven heating. Doesnt the clay effectively evenly heat the spine in an irregular pattern, so when you quench, the areas that have no clay are able to harden quickly, while those areas insulated by the 1500 degree clay remain hot longer, not hardening, causing the line to follow a vauge pattern to the heat being held by that clay on the spine?

Maybe I still am way off.....
 
TikTock said:
Without using a torch or clay, how would one create a wavy, exxagerated hamon? I would think you'd need uneven heating. Doesnt the clay effectively evenly heat the spine in an irregular pattern, so when you quench, the areas that have no clay are able to harden quickly, while those areas insulated by the 1500 degree clay remain hot longer, not hardening, causing the line to follow a vauge pattern to the heat being held by that clay on the spine?

Maybe I still am way off.....
Click to expand...


You are 100% correct. Some like to make it seem more complicated than it really is.
 
Looks pretty cool, TikTok. Because the "waves" are so tall, you probably didn't have much of a chance of avoiding getting a second quench line.

I usually shoot for around 1/3 of the knife left "exposed" (no clay).

The first few times I did it, I had the clay really thick. Then I tried it with clay about 1/4" (+/-) thick. Exact same results. So, clearly, I have been using less clay. I don't know that it hurts it to have more clay...and sometimes I have had to "reapply" some clay to fill cracks, patch things, etc. in order to get a good quench.

Be sure to post a pic when you're done!
 
I hope I'm not being misinterpreted. Painting the clay in wild patterns will not yield a wild hamon unless the time the blade is soaked for, the temperature, and the speed of the quench is perfect. When I first started working with hamons I assumed that if I came up with dynamic designs in clay I would have the same dynamic hamon, which isn't --and wasn't-- the case.

There is absolutley no magic in hamons, but if you want controlled activity all variables must be removed. Not to imply that I am anything but a novice, to get to the point I am at now I had to take exact notes, observations, and many experiments. When I came to the painful realization that clay itself wasn't giving me what I wanted I went back to the drawing board and just worked with hardening lines.

When I began closely studying the hardening lines the first thing that jumped out was the cooler ricasso and tang were being hardened, even though they were not at the same temp as the blade. I went from the previous temperature and lowered each successive blade slightly until the blade no longer hardened.

Then I started working with soak times. I found that a blade that is soaked for a longer period of time at low temperatures would still come out screaming hard. So, those lower temp blades that didn't harden under the previous scheme were hardenable with the increased soak times.

Then I moved to the quench, I tried peanut oil, vegetable oil, Texaco Type A, ATF, water, and Tough Quench. I've settled on Tough Quench; it provides the results I'm after in performance and in aesthetics.

I've forged, ground, experimented, and tested at least two or three dozen blades, and I'm still making slight changes to the process. I've made more blades for testing than I have finished work, I don't think anyone needs to go that far, but it certainly helped me. By the way, I'm still looking for improvements in performance of all the blades I make :D.

That was a really long winded way of saying clay is the last variable to play with; thermal cycles, time, temp, and quench are much more important.

Here's a very early, very ugly w1 blade that was done without clay. One of these days I'll get around to posting my notes....
http://img.villagephotos.com/p/2003-8/336406/102_0216.JPG Look at some of Matt Lamey's recent bowies for better executed knives with the same visual phenomenon.

And here's a slightly more recent blade done with clay. http://img.villagephotos.com/p/2003-8/336406/104-0438_IMG(2).JPG

The one thing I have to say is don't let anyone talk you into believing there is any voodoo involved; just very specific conditions. If you take close notes you'll be able to get the exact results you're looking for.

Matt
 
I agree with everything you said, Matt. Thanks for clarifying.


p.s. must be my computer...I can't see the images. ?
 
Cool, thanks!

Can you not see my pics, or later ones?

I appreciate all the info. From looking at my hamon (will get pics later), my clay was too low to the edge. My main transition line is low ofr my tastes, but not so low I want to re-do HT....once i get it sanded up to a higher grit and a proper etch, we shall see what happened up around the clay.

This is alot of fun....can't wait till my next attempt once this one is done!
 
At the time of this post, Matt's fotos are now showing up on that link... don't know what the problem was earlier.

TikTock, your fotos have been showing just fine. I'm anxious to see how the finish-polished blade looks..

Has anyone ever multiply-broken these zone hardened blades to notioce how the steel crystallizes inside? Is the hardened area completely through the blades below the line? Very interesting topic.
 
Tik, if you don't like what you see do it again. I just quenched a 13'' clay coated blade 4 times and I thought I knew what I was doing, didn't like the hamon until the last quench. Almost slung it out in the woods after quench #3 but thought what the hell, I'll try one more time.

My own experiments show Matt and Nick to be dead on. Keep in mind lower heat, longer soak and thinner clay will result in cool hamons. I put my clay on around 1/8'' thick + or - never thicker than 3/16'' and if I'm edge quenching I don't coat the spine with clay.

Producing hamon on blades is a sickness that is not easy to recover from :p
 
Just want to reinforce what Matt and Don have posted.

The clay doesn't have to be thick at all. I'm like Don, 1/8"-3/16"...

:D
 
Wow....i'm stoked!

heres 400 grit, double 5 second etch....some crazy action going on.....

cant wait to see 1200-2000 grit....

Lemmie know what you think!!

That light near the tip is glare. Hamon doubles back and curves back to the spine, like my clay is oriented.
Looks like I had some pretty weird heat migration after the initial edge hardening...like the heat creeped back down from the clay and created the second line, then the odd dips and valleys. I think with a great polish, there is lots more to see here. There are faint swirls that almost look like smoke running from the spine in a few places...

hamon.jpg
 
You got that right...:thumbup:


TikTok - definitely got a neat-lookin' blade. :cool:


Be sure to post a write-up how you did it (for others to read).



Looks like the hardened area is just as Nick predicted, but the action above the line justifies the clay, imho.
 
You definitely got some wild action going on in there! :)

Cool stuff.


Beginner's luck. :(


HAHAHA!!!!! :D j/k :p
 
Thanks for clarifying. I agree, no mystery, just good heat treat sence. Fred :thumbup:
 
Very cool pattern, I'd prefere to see the hardened line a little higher, but outstanding work non the less. I've got to get out there and play with some clay, the posibilities are endless.:thumbup:
 
Thanks guys! This is proof point these forums are invaluable!

HT went as follows:
3X normalized
GF kept 3 gallons oil at exactly 130
I moved the blade around constantly, and turned down the forge when the edge looked close to critical....the clay was not totally red. I slowly brought the temp up and soaked until clay was same color as blade, then brought to critical and held there for maybe 20 seconds.

Quench was tip first, then a roll down to the edge where I had to hold it for a long time to get that clay and spine cool enough.

I, too, would prefer the main line a bit higher, but can't bear to wipe this slate clean....

I agree....i see lots of clay in my future, too..im hooked!!
 
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