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Hamon: attempt symmetry, purposeful assymetry or just apply the darn clay?

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Adam Reggie
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Active Member Apprentice Bladesmith (5yr)
Topic starter
 

I am attempting my first hamon on an actual knife tomorrow, the clay is on and drying as I type this.  I was thinking as I was applying the clay if it would be preferable for a hamon to be as symmetric as possible or to just make each side unique to whatever strikes your fancy.  I did not in this case make any effort at symmetry, more like trying to take up about the same amount of area on each side.

I know this is likely opinion based, however is there a general aesthetic consensus on this?  If not do you personally have a preference?

And, this is theory crafting as I am thinking about it, would clay being applied symmetrically perhaps improve the overall hamon during the quench?  If the clay insulator is not roughly even on both sides of the blade perhaps the quench oil would be able to quench the opposite side of the blade where they clay isn't, harden enough and wash out the hamon under the clay.  That may be just over thinking it however.  

 
Posted : 24/11/2022 8:27 pm
BRION TOMBERLIN
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Forum moderator Forum Moderator
 

 Hello Adam. To answer your question, yes, symmetry will help. There was one school of Japanese smiths who had different hamon designs on each side of the blade. The main thing as you said is about the same level on both sides. If you have varying heights you can introduce warps and as you said wash out some features on the lower side. The thing is you can, but you may not depending blade thickness and quench temp. A lot of variables. What steel are you using?

Brion

 

 
Posted : 27/11/2022 3:09 pm
Adam Reggie
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Active Member Apprentice Bladesmith (5yr)
Topic starter
 

Hi Brion, thank you for the response.  I am using W2.  Unfortunately the first one I quenched (parks 50) cracked at a sharp corner between the blade and the ricasso.  I should have known better and filed a radius on the second blade of the batch.

I decided after I wrote that question that the risks of asymmetry didn't outweigh any benefit from trying to be even on both sides.  Fixed my sharp corner, clayed and quenched the second blade successfully and tested at 66Rc as quenched.  The blade is about 1/8 at the spine and the hamon that I can see before etching is not as lively as my pattern, but we will see what I get.  I think my clay may have been a bit to thin.

Best Regards,

Adam

 
Posted : 27/11/2022 4:01 pm
Adam Reggie
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Active Member Apprentice Bladesmith (5yr)
Topic starter
 

So the results of my first effort outside of test pieces, I intended the hamon to have "fingers" down towards the edge:

 

Also my first time etching my name in a blade.  I think it's way to large, not a problem since this one is going to be mine.  I will shrink that down by about a third.

 

I have another one clayed up with thicker clay for the fingers.  This is kinda addictive.

Also I welcome any constructive critique or criticism.

 

Best Regards,

Adam

N

 
Posted : 27/11/2022 8:15 pm
Kevin Stinson
Posts: 15
Eminent Member Apprentice Bladesmith
 

Yes hamon are adictive. also best way to bring it out is a hand polis ending tip to tang, with no residual scratches in the tang. i will dip my blade in ferric chloride for about 5-20 seconds between grits and alternate going tip to tang then carefully edge to spine. I also am so obsessed I use a magnifier to make sure I get all the scratches out. you can use vinegar likely with a longer soak time I have not used vinegar in years and had ferric before i started handpolishing so sorry i cant help you there.

I find taking a picture from one side does help with symmetry a bit. What's your heat-treating setup? if you doing forge heat treat (which i do right now cause i am unsure if my shop can support an oven), I would go with something like 1075. I find 26C3 gives a really beautiful hamon. But I have not used it much as i just bought a bar to try it out. I Like to clay the spine to where I end the clay and the front of the ricasso where I want the hamon to terminate, and the shoulders just to prevent any sharp lines. I likely overthought my claying but i worry about how the spine cooling quicker than the sides could affect the blade. also, when going for a quench, you want to go 'colder'  to get a more vibrant hamon. For example, 1075's I think the term is optimal hardening temperature is between 1450 f and 1480f. Depending on how far you keep your heat source from your quench medium you might want to go at 1455 (i don't know the rate of cooling steel has in the air so I don't know how to actually calculate this properly nor do I have the right tools to figure it out) so your at 1450ish when you go into your quench medium.

Also, leave your steel in your quench medium until it stops boiling and is just bubbling, then scrape off the clay. if its easy to scrape off the blade has hardened if you can't...the blade did not harden. my understanding of why this is is that when Martensite forms the speed of the transformation is the speed of sound and that transformation caused the clay to break its hold on the blade.

https://www.alphaknifesupply.com/shop/26c3-carbon-steel

 
Posted : 28/11/2022 1:06 pm
BRION TOMBERLIN
Posts: 0
Forum moderator Forum Moderator
 

Looking good Adam, and W2 and parks50 is what I would have recommended. What temp did you quench at? The quench temp plays a big role in activity, as does clay thickness. Again nice job for your first attempt.

Brion

 
Posted : 28/11/2022 9:02 pm
Kale Cope
Posts: 13
Eminent Member Apprentice Bladesmith
 

Can I ask where you got your W-2? I've been struggling to find some for a while

 
Posted : 28/11/2022 11:44 pm
Adam Reggie
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Active Member Apprentice Bladesmith (5yr)
Topic starter
 

Kale, I purchased this W2 from New Jersey Steel Baron.  I am in PA so the shipping to me is about a day or two, which is great.  Also I discovered if I keep the lengths to 24 inches the shipping is a bit less for the order.

 

Brion, thank you, I have seen pictures of your work so your words carry weight to be sure.

I am targeting 1460° for the quench.  I am not sure how low I can go and still get the edge fully hardened.  This is with a PID controlled home made heat treat oven.  So I suspect it is +/- some amount of degrees from what a commercial oven would be.

 

Kevin, I tried vinegar as well in my tests but I wasn't satisfied with it during my initial tests.  I may try it again in the future.  I am using 16:1 Ferric Chloride, which is more diluted than i planned, but I didn't consider that the Ferric was only 40% when I mixed it.  As I noted I am using a home built 240V heat treat oven.  The clay (Rutland mortar) flaked off very easy after the quench which was okay I think.

I was actually finding with .188 thick test coupons, ATP-641 alone was enough to prevent the W2 from reaching full hardness.  It was only testing at about 40 Rc.  A knife profile, however is reacting much differently than .188 thick flat stock.

 

Best Regards,

Adam

 
Posted : 29/11/2022 9:49 am
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