Does a hamon degrade with repeated tempering?

Hi guys

I recently heat treated a blade trying for a hamon by differentially hardening with clay. The blade is 1095 and survived the quench but warped. I have tempered it and got it straightened a bit using a clamp during tempering. I will have to do this again as it isn't completely straight. Does reheating like this wash out any potential hamon?

 

Everyone I have talked with has said it will degrade with tempering. As for myself I have been lucky and not had any warp that I could not grind out. I gave this one three tempering cycles at 350deg and the hamon still looks good (better than my picture)

You probably don't have much choice but temper again and see if it will straighten out. The only other option would be normilize straighten and re harden. Quenching is always the most stressful part of knife making, both for the maker and steel.

 

I really don't want to anneal and reharden if I don't have to. I feel lucky that it didn't crack the first time as I quenched in brine. I can see signs of the hamon in it now with just sanding off the crap from heat treating. It could be good if I don't ruin it by retempering.

 

Personally I would try tempering again. Are you using a bar to clamp it straight? If you are, try shimming it with a penny a little past straight (I hope that makes sense). Hope it works for you, quenching in brine is not for the faint of heart

 

Lol. It was a goocher but I wanted to take the chance for a hamon. I actually took a video of the process to see my reaction if it broke in the quench. I did clamp the blade past straight with a piece of angle iron an washers. I knew the blade was a bit thin going in and may not be perfectly beveled (draw filing) which I'm sure contributed to the warp. I'll post some pics when it's done.

 

Well....I tried straightening again while tempering. There is still a warp in the edge but not in the spine, a slight 'S' shape. I'm really wondering how I didn't break it. I am going to try rigging it up one last time and heating before I give up on it. For my own amusement, I sanded off the oxides and I'm sure I've got a decent hamon.

 

Do you have enough width to grind a little off the edge? Then you could straighten the edge by grinding

 

Hi Brad

I wish I could grind but I don't have a grinder. This blade was done freehand with hand files. I have taken most of it out by reheating and clamping. I don't know if I should finish it out and build the knife or keep reheating and clamping as it's really my only option. On the good side, I can clearly see the hamon at a quick 400grit finish. It's better than I could have hoped for. Like I mentioned before, I think the imperfection of hand filing everything might have contributed to the warp, not to mention that I left it thin before HT. I can see the benefit of grinding, not only in speed, but in correcting these problems after HT. It bothers me that it's not perfect but I don't want to toss it. Thanks for the advice, I greatly appreciate it.

 

Lol. I can't put it down now that I can see the hamon so hanging onto it unfinished for a year is not an option. I appreciate the offer to grind it out but I'll have to pass. I straightened it cold just a bit more. I must have done something right because I had it clamped in my vice while I pulled it straight, no breaks. The edge has a very subtle warp
in it that annoys me but I think I might finish it out now.

 

This is not the best grinder out there but it might help you get started
http://www.leevalley.com/en/wood/page.aspx?p=44884&cat=1,43072
http://www.leevalley.com/en/wood/page.aspx?p=48040&cat=1,43072
I started with one of these and it beats a file. I still use mine for sharpening and small stuff

 

Thanks for the info Brad. I might just check that out. If it speeds up the process for me I will get more practice in all aspects of knife making. Then I can decide if I want to invest in a 2x72.

 

A 2x72 grinder is what 90% of the knifemakers are using (at least the guys I know). There are still some cheaper options like the Lee Valley one that let you get your foot in the door without breaking the bank. The biggest downside to a 2x72 belt grinder is price. Build or buy it is still going to cost. If you do buy get the best you can't afford, or do like me and buy something cheap and regret it.

 

I built my own 2x72 for about 500 bucks and I'm sure it could probably be done cheaper. If I had to do it again I would probably buy a Kmg with platen setup and step pulleys. That setup should be attainable for under 1000 bucks.

 

I'm 90% done my build and I'm into it for around 1500. My variable speed set up is the bulk of my cost.

KMG are great but they will not have anything to do with Canada, I tried no shipping for the grinder or parts. Wilmot will ship here but they are not cheap (3000=+shipping). Terry (I can't remember his name on here) is trying to bring a quality, affordable grinder to the Canadian market.

 

Thanks again for the advice fellas. I am hand sanding the blade and I have it up to 1000 grit. The hamon is definitely there and I can see some of the finer details coming out. I used to look at knives with a hamon and think how 'cool' they looked. Now that I have pulled one off, I can't put the damn thing down! I might even give it a family name. My wife has zero appreciation for this and I can't really blame her for that I guess. I'm starting to think that most people would just look at it and say 'that's neat...' Am I the only one who thinks like this?

 

No your not the only one but we are thin on the ground. I have had pretty good results using lemon juice and flitz polish to bring a hamon out after I get it sanded to 2000 Gr. A couple pictures would not go astray

 

Brad

Pics are coming. I had to take it back to 400 grit to get out some J-hooks....ugh! It's back up to 600. It's taking me awhile to learn how to sand at these higher grits. Gimme a couple of days and I'll have it etched,I hope, then I'll post some pics. BTW where do you buy Flitz? I've heard lots of makers are using it but I haven't seen it so far.

 

The only place I see flitz for sale is a local outfitter and he knows how to charge for it.