More hamon questions.

IanBryant

Well-Known Member
As some of you may know, I recently did a differential heat treat on a 1095 blade...and I could see the hamon after hitting it with some emery cloth...so it was there....
Now I can't see it.I left an almost unreasonable amount of meat to grind off (I thought it was around .05 but a jig malfunction just made it look that way...it was closer to .075) I took it home (I heat treat at work) and finished the flat grind to 400 grit and can't see any traces of a hamon now. I did run a file down it and it cut to roughly where the hamon line would be and then skated so that's giving me hope.

I suppose what I'm asking is , can a hamon be ground out? My metallurgical instincts tell me no due to the nature of such a beast but this may fall under the vast category of things I don't understand.

....or maybe I just worry too much and it'll be there after I etch it....
 
Before and after pics would have been helpful in determining the issue....but let me ask you this...I don't know how much experience you have with creating hamon but are you sure what you saw before grinding was the hamon?

The clay almost always leaves a layer of scale that looks like the clay pattern, more or less, and many times guys think that's going to be the hamon but it's a relatively shallow effect of the clay that grinds right away.

Any true hamon would be quite visible after grinding with a 120 grit or even a 60 grit belt in good strong light, such as a florescent shop light. The real fine activity might not be seen then but could be brought out with fine polishing and etching cycles. But the main transition line should be highly visible after finish grinding with no hand sanding or polishing.
 
I have no experience with hamons, this is #1 for me. I could see it up to 120 grit if the light hit it right (the light in my shop is terrible) and the scales from HT was long gone by then. It wasn't until the 220 and higher grits that it "disappeared " which is where I verified the differential HT with a file...because I could still clean those scratches up...I should've taken pictures I suppose. I'll still etch it and see, I just want to single out any mistakes I may have made to avoid them in the future.
 
Yeah, that is strange for sure. If the blade is good and clean prior to etching in ferric chloride, the etch will tell you a whole lot. That's the next step I think.
 
Yeah, that is strange for sure. If the blade is good and clean prior to etching in ferric chloride, the etch will tell you a whole lot. That's the next step I think.

Okay...so etch then polish? I'm sorry, I'm not intentionally thick headed I promise. I thought that etching came after polishing...then just kind of a touch up to remove oxides from the etchant(then buffing) Im intending to use vinegar because there are no local sources for FeCl here so I'm ordering it for future use.


Edit: I suppose I could disclose that I only ground to a 400gr belt. Only because that's the highest grit that I have, the rest will be sandpaper. So should I go up to 1200 before etching?
 
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FeCl substitute is PCB Etchant. As to the rest of your dillema I have no experience.
In theory the clay should have left a seriously visible line from all I have seen.
 
I only go to a 400 grit belt finish too. From there, I start hand sanding with 400 grit paper. I take my blades to a good clean 800 or 1000 grit hand sanded finish. 1200 would be good too. I clean with dawn dishsoap and hot water prior to etching. I etch in ferric chloride, diluted with distilled water, 4 parts water to 1 part ferric chloride.

After etching, I'll sand the black off with 1500 grit paper. Then I'll re etch and sand with 1500 paper and repeat those steps until I get the look I like. Generally speaking, the more fine activity that I think I have, the more etch/polish cycles I'll do. Usually 6-8 cycles is the max and quite often 4 cycles will get me where I want to be. As a last step, instead of the 1500 grit paper, I might do a polish with loose powdered abrasives and wd-40.
 
As I was leaving for work today, the ups truck showed up with my ferric chloride so I may stay up until the wee hours of the morning polishing on the blade so I can etch it and see.

It also occurred to me that I did a 3rd temper at home (the first two were too low of a temp for 1095) and I may have banjaxed everything using the kitchen oven.
 
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