First Hamons

69_knives

69_knives

Joined
Nov 20, 2008
Messages
1,855
Just a few pics of this weekends work.

I wanted to see if I had decent hamon before I got too far into grinding and finishing so I rough ground with 50G and soaked the blades in room temp vinegar for about an hour then scrubbed lightly under water using a worn SOS pad.

The one on the left I'm pretty sure has to be re-hardened as the hamon drops out mid blade, the second one should be ok, though a little narrow; third, the biggest blade has a real narrow hamon and I don't think it looks OK. 4th, I like but could be a little wider hamon at the ricasso. the first 4 were 1095 forged, 5&6 are KSO's (knife shaped objects) I cut from 1084 HR, the hamon is harder to see but definitely there, 7,8&9 are stock removal KSO's cut from 1095.

gedc0415-0.jpg


gedc0403-0.jpg


gedc0400-0.jpg


feel free to critique or offer tips on getting better hamon on the big blades. I think either I used too much clay or too low on the blade, I'll post a pic of the clay on one blade, it definitely looks nothing like the hamon.

Normalizing...

gedc0397-0.jpg
 
So, that's where all my vice grips went.
nice, lets see the end results.
vern
 
I have no advice to offer as I haven't done this yet, but I hope to do so soon, so I look forward to seeing your results and how you went about it. Thanks for the post.
 
the middle knife in the top 2 pics is good. Personally, I shoot for a hamon that's 1/3 the blades height.
 
It would be a bit easier to find the problem(s) if we went one blade at a time. Still here are some questions. What quenchant did you use and how thick are those blades? It does look to me like you went a little heavy on the clay. But without all the info who knows? Also what is your heat source?
 
Of the 3 bigger blades the middle one was from 3/16" stock and the other two were from 1/4", the smaller forged one was 5/32". When I cleaned them up, I took what I thought was quite a bit of material off to remove all the decarb and what-not and there's still about 1/16" at the edge.

Heat source was my forge with a pipe muffle and quenchant was canola/rapeseed oil @ 130°F.

gedc0376-0.jpg


Now that you mention heat, I wonder if the thicker blades didn't heat up enough.

Basically, going by Admirals quench temp range of 1475 - 1575, stuck the probe on the side of the blade opposite the heat source and once the temp hit 1475 I timed how long it took to get to 1575, generally around 2.5 - 3 minutes, so I figured this was allowing enough 'soak' time and high enough temperature to get carbon into solution and make a good HT. As soon as the gauge read 1575 I quenched the blades, agitating vigorously.

Maybe on bigger blades I need to use the well heated forge by itself without the muffle.
 
ya, chances are you didn't let the larger blades soak enough, combined with the cement that was a bit thick.
 
When I first started with hamons, I would put the clay on about .25" thick, and even though it was 2/3rds the way up the blade the hamon would often be too close to the edge or run off the edge. Someone on the forum suggested that I make the clay thinner. Now I keep the clay only about 1/16" thick, and I have much better control of where the hamon ends up.

Other things that help are to keep the temperature a bit lower and to use a faster quenching oil. The way I understand it, the clay, or even the thicker steel at the spine, holds heat and radiates that heat down towards the edge during the quench, keeping non-clay-coated steel from getting past the pearlite nose. Keeping the clay thin, starting from a lower temp, and using a fast quenchant all help minimize this and give you more control over where the hamon ends up. If I'm misunderstanding things, one of the more experienced makers can please correct me.
 
Thanks for the suggestions. I thought the thin clay might have been what messed me up the first time so I tried some real thick stuff like plasticine but I can see how that would cause the blade to cool a lot slower. We'll see how they come out the second time.
 
My honest guess is that all the variables are off a little. Have you ever tried to harden a 1095 blade without the clay? If so did you etch it to confirm that it was completely hard? I think you need thinner clay and faster oil. As steel comes up to temp it tends to do so in an even arc. Even a shallow hardening steel will have a relatively strait hard/soft transition line if quenched when only the edge is at temp. The hamons on your knives are more jagged. This leads me to believe that more of the blade was at temp when quenched than the portion that was actually hardend. So for some reason your blades did not quench as fast as they needed to. Either because of to much mass or to slow of quench. Change one of those things and see what happens

Good luck
 
The jagged or wavy hamons was intentional, I clayed all of the blades like the one in the pic, in fact the blade in the pic with the clay is the blade on the very left with the worst hamon. I didn't sand or grind the blades either before hardening, I suppose that would also thin down the mass a bit more.

I've never tried to harden 1095 in oil without clay, only in water and you can guess what happened there.
 
Robloveday is right on the nuts. Too much clay, heat is likely too high for good hamon activity, and you need a faster and more consistent oil.

Leave one of your blades thick. This way, if you end up with something that sucks, you can do it over again! Normalize. Rough grind it to 220 grit or so, clay coat it and heat treat. Start with lower temps and work up (some of the coolest I've done were using 1400 for austenitizing!), soak long enough to get the steel under the clay to forge temp (2-3 minutes usually seems enough, but you can try more it you want). Quench.
I have no idea if canola/rapeseed is fast enough, but you seem like you're into this, so get a real quench oil and make your ability to maintain proper temperature control worth something.
After quench, do a snap temper at 350 to keep the blade from eating itself only long enough to determine if you dig the hamon. Do a quick sand to 220 again to clean it up, and look closely - you should be able to make out hamon in the right light. Etch if you want to. If it sucks, normalize again and try a different temp!

Do one first, see what gives you the best results, and use that as your benchmark for the next batch.

Remember also that there is no advantage to improperly heat treating steel this ay, other than that we like how it looks!
 
Thanks, Matt.

I've got a few variables to check out and modify and see what comes out.

To get decent quench oil I would have to buy a 45 gallon drum of it that would cost me about $800.00. I read about a lot of people having success with canola oil so I went with that.
 
You must log in or register to reply here.
Back
Top