This is my first attempt at a hamon so I was not expecting perfection but I also was not expecting what I got.
First off, the steel is 1075 from NJSB. The Mn content in this batch is 0.434.
I forged the blade by hand then normalized and annealed in vermiculite.
After refining the profile and roughing in the bevels on the grinder I hand sanded to 120 grit.
I’ll include a picture below of the blade with the clay applied. Using hamon 1800 clay I did my best to keep the thickness consistent along the length of the blade. It wound up being between 1/16 and 3/32 I think.
After allowing the clay to dry thoroughly I austenitized at 1475-1480 (according to the thermocouple in my forge) and soaked for about 5 min before quenching in parks50 heated to around 70 degrees.
The blade did not warp and the clay mostly stayed on. In fact it was quite difficult to remove.
Tempered one hour at 350 and then 2 hours at 375-400 (according to the oven thermometer in my toaster oven).
I ground and sanded and polished all the way to 2000 grit then etched with lemon juice twice and vinegar once removing the oxides in between.
Long story short, I followed all the advice I could find on the internet haha. As you can see I definitely produced a hamon but it is not pretty. Also I am confused as to why it widens and fades to nothing as it nears the tip. Was my clay too thin? Too thick? I have already decided that the pattern in which I applied the clay was not helping me.
Please chime in with any advice! I’m already addicted to this hamon stuff and I want to do it better next time! 🙂
Thanks in advance
-David
Here is the picture of the blade with the clay applied. I couldn’t figure out how to attach more than one picture in the first post
Also, as I was getting excited about how this blade was turning out and the plans I had for the handle I’m tempted to normalize and start the whole ht process from scratch in order to try to get a better hamon. Is that a bad idea?
One last note: I was very careful to not overheat the blade while grinding after ht. I grind freehand without gloves so if it was too hot I would have known!
Hello David. Well there is a hamon there. That is a good thing. !075 does not really need a soak, but it won't hurt. Usually when that happens it means that the blade was at a higher temp than 1470 or so. Are you sure your thermocouple is reading accurately? You can see in the thicker part of the blade near the tang that it came close to following the clay. Did you leave the blade in the parks when quenching? or did you pull it out after a second then back in?
Brion
Hi Brion, thanks for your feedback.
I’m not 100% sure my thermocouple is accurate. Unfortunately I don’t know how to test that either. Do you think I would be better off just using a magnet to make sure I’m above critical?
I left the blade in the parks for about 10 second and agitated it up and down the whole time. Do you think I should try an interrupted quench next time?
-David
I don’t know how helpful this will be but here are some blurry, zoomed in stills from a video I took of the quench. To me the color of the blade looks pretty even but it was daytime so maybe my perception is off.
Pic 3
Sorry I guess picture 3 file size was too big. It didn’t add much to the story anyway.
The color looks good David. You could re do the clay and try again. I am guessing you normalized and thermal cycled after forging. You can just recoat it and do over, or you can give it another thermal cycle at 1450 then reclay. Just curious, is this new 1075 or old stock from NJSB?
Brion
A really good hack for when to quench most of the steels we use is also a good way to check if your thermocouple is reading correctly. Most of our steel hit quenching temp at 1475*F.
It so happens that table salt also melts at 1474*F. So go get yourself a small box of large grain Kosher salt. Set a chunk on a piece of scrap steel and bring the oven or forge that you use up to temp and watch the salt and temp readout. If the temp readout doesn't read 1474 when the salt melts, you know how much it's off by.
If the temp readout is different than 1474 when the salt melts, remember that number and quench when the blade hits that temp.
For those of you who do not have a thermocouple or a HT oven, and are using a baffle tube in the foge to heat blades to quench, use this trick in the baffle tube. When the salt melts, it's time to quench.
“So I'm lightin' out for the territory, ahead of the scared and the weak and the mean spirited, because Aunt Sally is fixin’ to adopt me and civilize me, and I can't stand it. I've been there before.”
Thanks Brion. Yes, I normalized and thermal cycled after forging. I think I will try it again but this time without a soak. As for the steel I’m not sure what constitutes old stock but I do know that I purchased it in September of 2020. So maybe the specs I’m looking at for the current 1075 batch are out of date.
Joshua that’s brilliant! Thank you for that tip! I’m definitely going to throw some salt in the forge on this next attempt and double check my readings.
-David
I was going to give my long answer, but just to Pop's Knife Supply and look at the two videos on this Hamon 1800 product.
Notice the difference on how the clay is placed as compared to yours.
Now, I will say, your steel is hardened way up under your clay. There is no need for a long soak at temp for the steel you used. On your next try, do NOT wait until the entire steel is hot - only the area that is exposed and then maybe just up a little more under the bottom edge of the clay.
Quench quickly.
Thanks Karl. I think the exaggerated pattern I tried could be a big part of the problem. I’ll try a simpler one like in the video next time. Also no soak time.
-David
