Tips for hamon?

I

Ian Fifelski

Joined
Oct 4, 2017
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528
I am working on a hamon on a 1084 bowie. This is my first hamon and first bowie. (any critiques on the design are welcome)

It is an auto-hamon (clayless) and has showed up because of the thickness of the steel towards the spine, 1/4. I really am glad with its location on the blade and want to bring it out as far as possible on 1084. It was hand-sanded to 1500 grit. It is currently (in the many photos) after 3, 8-15 minute etches in warmed vinegar and one warmed lemon juice rubbed etch, polished between each etch.

I have a few questions:

  1. What is the best way to polish oxides from the plunge lines? I am polishing with 1500 silicon carbide abrasive powder mixed with water to a watery paste using small make up pads. I have been able to get it sometimes but others the more I try to get it, I make j-hooks and perpendicular lines.
  2. On one side of the blade the hamon line is less crisp. Again, this is a clayless hamon so it couldn't be because of uneven clay coating. Does anyone have an idea of what could have caused this? Can I even them up? Maybe 2 or 3 extra lemon juice etch on just that side?
  3. Like I said above, I want to bring it out as much as possible with 1084. Am I just wasting my time if I do more than 4 vinegar soak etches and more than 6-8 lemon juice etches? Will I just start pitting?
  4. There are some spots on the blade (especially noticable on the tip of side #2) that wont polish out. Are they spots of the hamon? decarb?
  5. Any other suggestions?
I am pretty happy with it overall so far. There are a couple of things like washing out the grind lines a bit from hand sanding and slightly uneven grinds.

If you have any suggestions related to this at all, like the press fit guard (a bit concerned on how this will turn out) or handle, feel free to mention them.

Thank you all
(I know I am over thinking this and I probably could just try to figure these questions out, but a tip from another is always helpful)

a bunch of pics.. Side #1 is the best side, side #2 is the less crisp side. It is has a rough dirty polish.
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You're making j hooks and perpendicular lines with your polishing compound?

I can use a circular motion with 1500 grit sc and it's impossible to see.

Your pictures to me appear that you haven't sanded to a clean 1500 grit and your previous grit scratches are simply becoming more apparent as you etch and polish.
 
kuraki said:
You're making j hooks and perpendicular lines with your polishing compound?

I can use a circular motion with 1500 grit sc and it's impossible to see.

Your pictures to me appear that you haven't sanded to a clean 1500 grit and your previous grit scratches are simply becoming more apparent as you etch and polish.
Click to expand...
Haha, that is the last thing I wanted to hear. I spent hours on hand sanding, then went back to 400 grit and sanded up to 1500 again because is wasn't clean.

When I get j hooks, it is normally when the powder collects come to think of it. Should a hamon be polished in circular motion? I have been polishing back and forth along the blade and then near the end only pull strokes.
 
My point about the circular motion was only that you shouldn't see any scratch lines from the polishing compound, and if you are they're simply being revealed and not created.

I use whatever motion is convenient for the area I'm polishing.
 
Thanks guys, I think I was getting scratches because I wasnt keeping it watery enough and there was a clump that collected at the plunge.
 
If I remember right you stated in another post about hamon that you heated the blade with a torch. I bet that is the reason you have a sharper line on one side compared to the other. If you didn't flip the blade over on every pass of the torch one side probably got hotter than the other. I can't remember who said it, but this is not a true hamon as far as most makers would say.
 
I heated it with a propane forge, and I did flip it. That still may have been the problem though.

What is a real hamon? 'Willie71' Said that it is not considered a real hamon, because he thought I did an edge quench. This is not an edge quench, the line is there due to the fact of thicker and thinner steel. Because it is so thick (1/4) the quench only cooled the thinner part of the blade fast enough to harden it. I believe this is called an auto-hamon, and is considered a real hamon?
 
While I'm sure there's a 14 page essay with more Japanese terms than I can remember on a traditional hamon, for me to personally consider something a hamon there needs to be a couple things present. First, is the steel itself, what is it's composition? It should be high carbon, low alloy, with less than .5% manganese. Second, there should be more than a simple line between martensite and pearlite, there should be a transitional zone.

Too much Mn or other alloys that cause deeper hardening reduce the transition zone of a differentially hardened blade. 1084 is .75% Mn, while the current 1075 is lower Mn and 1095, W1, W2, Hitatchi, etc are even lower than 1095. 1084 seems to have too much Mn to get what I (myself) consider a "true" hamon.

I used to think that 15N20, though low Mn, was too deep hardening to get a true hamon, but now I'm not sure that the nickle actually has as much impact as the slight amount of Mn 1084 has over the other simple carbon steels.

The reason no one wants to answer is unless you go with a purist nihonto-ish answer, there really isn't a concrete definition and we probably all think a little bit differently about it.

But your blade to me appears to show a clean transition between martensite and pearlite, what I would call a temper line, and none of the other structures that make up the "cloudy" or "wispy" or "banding" that occurs with what I consider hamon.

I'm certainly no expert and there are many here with more technical, historical and practical knowledge on the subject than I. This is just my opinion.

See these first two pictures. Same blade, tilted in the light. The transition zone changes color and is more than just a separation of martensite and pearlite.
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Or here with a ferric etch, you can see there is a transition zone as well, that actually appears as 3 different colors.
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Looks good man! I’d go in and try to get out some of those lower grit scratches but I love the profile. Lookin good!!!!

Jay
 
Should I go back and hand sand again? I feel like I can get away with leaving it (the scratches look worse in the photos) but I don't really want to 'get away with it'. I also really do not want to hand sand for a third time... :eek:
 
Developing a hamon ( or temper/hardening line) requires etching - sanding - etching - sanding - etc. Here is a VERY basic procedure.

Give it an etch ( you already did that), then hand sand to above the scratch limit ( the grit that shows no discernable scratches), which is usually 1000-1500.

Etch again and re-sand as needed to get all the places crisp - like the plunge.

Now, you start etching and sanding to "develop" the hamon. Selectively sand only above or below the hamon ( usually below).

Use various polishes and finer grits as needed to create the dark Ji and bright Ha. This is the dark upper area and bright edge area. Polishes like Flitz and Simichrome are used on the upper area, polishes like super-fine SC, tin oxide, iron oxides, chrome oxides, etc. , are usde on the lower area to get the desired look. You may also be etching these areas selectively with lemon juice, 15:1 FC, and 100:1 nitric acid.

If necessary, you can mask off one area with tape or nail polish while working the other.
 
I would leave it, that’s just me. Although it doesn’t have as much activity as you may like, there’s still an obvious change in the structure and it’s visible.
 
If you're going to be chasing the hamon fairy, you're going to have to sand cleaner. Don't rush it. Don't move on to the next grit before you get all the scratches out. Scrathes will mud up the hamon. You should be able to see the hamon before you etch it at all. You have a temper line on one side and your "crisp" side I can see Ashi and the makings of a Hamon. The less crisp side could be a number of things. One simple cause, could be that you didn't get through enough of the decarb. There is no single concrete answer. Hamons are an unforgiving B#%?!. You have to experiment. Sand cleaner!
 
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