Help toubleshooting hamon attempt

Josh Dabney

Josh Dabney

Moderator
Ok fellas here's what I got.

I finally got some Parks 50 quench oil so I forged out this 4" hunter blade over the weekend as a test blade for my HT and developing hamon.

Here are the specifics.
-Steel- 1095 from Aldo
-Rough forged at 2000 degrees
-Refined forging at 1800
-Normalized at 1600, 1500, and twice at 1450
-Rough ground to .050 on the edge
-Sub critical anneal 1 hour at 1300 drop 50 degrees an hour to 900 cool the rest of the way in the oven
-Follow Stephen Fowlers tutorial for clay using a skim coat over the entire blade and making the clay on the ricasso, spine, and lines approx 1/8" thick and matching on both sides
-Into a 1425 degree oven, wait for temp to come back up then soak 20 minutes
-Quench in Parks 50 pre-heated to 100 degrees for approx 10 seconds. Blade still hot enough to throw smoke at this point
-Scrape off clay, file check, then into the oven at 400 for 2 hours.

This isn't a super clean finish but I wanted to get it clean enough to get a clear look at whats going on so It's hand sanded to 1000 on all but the tip and plunge (with the exeption of some verticle scratches)

This pic shows the blade as it's fresh out of the ferric and still wet and untouched. I was trying to catch what I could see with my eye in the pic and any clean-up out of the etch made the detail in the upper portion of the blade invisible.

The white cloudy looking area shows right where the clay was applied. I was worried with the speed of the parks that it would harden underneath the clay but that was definately not a problem.

Servicememberbuild047.jpg


Any help or suggestions as to which variable to change would be greatly appreciated !

Thanks alot fellas, Josh
 
If that white, cloudy area is where the clay was placed, it seems like it worked out really well. You maybe running the clay thicker and farther down the blade than you might need to. I'd try less clay, farther up, with a more irregular design. You have nice control over your process. There's been some thought that electric oven heating needs more soak time, but you seem to have that covered.

Thanks for show the blade, Craig
 
Craig,

After reading your comment a couple times I think an additional pic is in order to show where the clay was put on the blade. After looking at the pic again I figure that the entire area over the hardened portion can be considered a "white cloudy area"

This pic shows where the clay was put on the blade to clarify better. I was anticipating a hamon that had much higher "peaks" between the lines that angle down from the top and at least a full 1/4" of hardened blade along the edge.

clay001.jpg
 
It may have been the wash over the entire blade. I had a similar result when I did that. I now only coat the area I want to "attempt" to control. Here is a couple of pics of before and after on one of mine. I'm not sure which one of these the second photo is of. I did three of the same pattern. I used the Rutgers refractory on these as opposed to Satanite.

Hamon 1.jpg

Hamon 2.jpg
 
Hi Josh,

Thanks for the follow up pic. Yup, it appears (?) that only a little of the edge hardened and that the clay didn't seem to influence the area that hardened.

Just a guess, but if I saw that, I'd figure that the blade was not picking up enough heat to harden. I'd try bumping the temp up or deciding if the blade didn't reach temp even though the oven stabilized (check accuracy and possibly more soak). I'd consider heating it up for quenching in the forge after you've done your favorite thermal cycling process.

Just guessing, but it's a fun area to play around with, Craig
 
Murph, previous to this I've attempted to get hamon quite a few times with brine (cracked 3 in a row) and have tried both coating only the pattern without a wash coat and coating the whole blade with Anti-Scale and both times it blew the clay right off. Now I do understand that the Parks is going to react differently to such variables so it may well be worth trying those methods again.

Craig, Not enough heat was my first guess as to the problem but it was honestly a stab in the dark. I think I'll give it another go at 1450 and see how it comes out.

Thanks for your input fellas ! -Josh
 
I think you've already found the likely problem Josh. I usually try right around 1455 when I'm going for a hamon on W1... Good luck!
 
I thought I'd update just in case anyones interested.

I clayed this blade back up tonight and heat treated it again at 1450 with a 35 minute soak and ended up with a very similar result.

Here she is clayed up
service001.jpg

service002.jpg


Cleaned up to 600 cork belt and etched
service007.jpg


20 minutes after hardening I aggressively file tested the edge and was able to file a little corner into the edge which leaves me to believe that even the hardened portion of the blade is sub-standard.

Now getting worried that quench speed is my issue I decided to throw it back in the oven with no clay at 1475 and see if I could fully harden the blade.

After that the file wouldn't touch it at all (even on the ricasso thats .210 thick) which leads me to believe that my quench speed is not the problem but takes me back to square one.

Now I'm thinking Murph may be right and the wash coat of satanite is giving me a problem or my clay lines are spaced too closely ????

Any other thoughts guys ?

Josh
 
Hi Josh,

I'd consider running the same process as your second try, but I'd try a wash coat that's much thinner, as in you're seeing more steel than coat. I'd also try clay that might appear only a third as thick as it seems to be in the pictures. Just guessing out loud, good luck with it.

It's interesting, Craig
 
Craig,

Thanks again for the suggestion. I almost snapped a pic of the clay the first time around but didn't. I thought being such an important step it would help others help me if they could see what I had going on.

It'll probably be a few days before I get back to it now. Since this one is hardened and tempered I'll need to forge out another blade and begin from scratch.

Thanks again for your help. I'll update after my next attempt.

Knifemaking sure is fun isn't it !!! :)

-Josh
 
Josh...

Based on my experience, your thin wash of clay seems a little thick. Further, the clay for your ashi lines also appears to be VERY thick.

If I were you, I'd do the following:
  1. Make sure your Parks 50 temp is within the operating temp specified. If I remember correctly the range for P50 is 70-120F. My shop can be a little on the cooler side, so I will usually pre-heat to 90-100F.
  2. Thin out the clay wash. When I apply the wash, the mix is VERY watery. I will warm the blade with a heat-gun as I apply the wash (or pre-heat the blade slightly in the kiln) so that the wash will stick and not just bead-up like water.
  3. It's OK to use 1/8" thick clay toward the spine of the blade... but your ashi lines should NOT be too thick or they will retain heat down to the edge. I use a putty knife just to "tap" the ashi lightly onto the blade.
  4. Make sure the ashi lines match up (are mirrored) exactly from side to side. If they are not exactly opposite eachother, they will spread the area of retained heat over a broader (less defined) area and distort the symmetry and cleanliness of your hamon.
  5. Use a quench-heat in the 1465-1475F range.

I'm no expert... but that's what I'd do.
 
Erin,

Thanks for the tips !!

I did pre-heat my oil to 100 degrees and plan to continue to keep that variable the same.

Will follow all advice on the next go round and see how it comes out.

I am thinking that since my issue is not enough hardening I'll be fine to bump my temp up to 1475 for hardening so I'm gonna go that route for sure. I've also been meaning to add a second fire brick (and possibly a 3rd) under my holder to raise my blade up closer to the thermocouple which is up on the roof of the oven. I'm thinking that at temps like 1425 even very minor variation of temp from top to bottom of the oven could have a profound effect on results.

I mixed my satanite for the wash VERY wet, but not watery. I know exactly what you mean though I've watered down anti-scale a bunch of times and it reacts exactly as you describe with beading up on the blade. I started with a heat gun but found it more convenient to grab my MAPP gas torch to warm my blade.

One question for satanite users- When mixing it watery it seems to remain to a certain extent "gritty" so I'm wondering if that grit will eventually disolve and make a true wash or will the grit remain grit ?

Thanks again guys ! Josh
 
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I second that your clay looks way to thick, I water quench (faster) and use much less,

This is a picture of a pretty well known swordmaker claying up a 1086v tanto (or wak?) prior to waterquenching, took a week long course with him last year on making japanese (style) pieces, took about 5 years off my learning curve :)

sc5.jpg
 
I believe I am taking a class with the same teacher (Howard Clark??) later this year, can t wait. That long of a blade pointing off the bench with that many people around looks Dangerous.


As for the hamon, I am no expert, but would try to be around 1475. For the outer wash, I make mine thin, like the thickness of those grains you are seeing. On w2 which is similiar to 1095, If I quench in parks at 1470, the hamon looks simiar to yours and close to the edge. If I quench in brine at that temp it is much closer to the shape of the clay.


Keep up the great work, I think you make awesome knives.
 
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Thanks for all the great replies fellas.

The hunt does continue. I forged out another blade today and got it normalized and ready for rough grinding and annealing. Hope to be claying it up and hardening tuesday.

Will update once I get #2 through HT.

-Planning to bump my hardening temp to 1475
-Thinner washcoat
-Clay applied at 1/16" MAX thickness.
-A little more space between the ashi lines

We'll see how that works out for me.

Thanks again guys, Josh
 
Josh, don't just thin the wash coat, eliminate it. The wash coat works with water quenching but oils are different. Completely scrub and degrease the surface of the blade and apply the ashi directly with no wash coat. I no longer mess with satanite so I cannot say how thick the ashi can be for you, if you get rid of that wash coat, 1/6" will be a bit thin, but with the furnace cement I use you do not want to exceed 1/8" thickness (height) on the ashi. Keep the ashi farther from the edge than what you want the hardened zone to be as fine pearlite colonies will sneak in there anyhow. Agitate the quench, keep the blade moving either from tip to tang or in a cutting motion in the oil until it is done.

1. Lose the wash coat
2. agitate
 
Kevin,

Thanks for the reply !

I forgot to mention that I'm currently quenching in the metal 5 gallon pail the oil came in so I do have plenty of room for agitaion. I quenched tip down and used the cutting motion.

Thought I'd ask if your using the Rutlands brand cement ? I shopped for it locally a long time ago with no luck but will order some and give it a shot. I did pick up a caulking tube of some other brand of high temp stuff and tried it on a couple knives but abandoned it once I got satanite. The stuff is pink and it puffs up like a balloon when heated then all the puffy stuff burns off and leaves a very thin coating stuck to the blade that stays till ground off. I'm curious if the Rutlands cement reacts the same way to heating as this stuff ?

Thanks again for the reply, Josh
 
After making japanese blades for 30 years , I have come to the realization that the Hamon can be difficult, and they never turn out the same . I dont pay any attention to temperature , I watch the color , with 1095 0r w series make sure color is bright orange near yellow , then touch with magnet to make sure blade is fully non magnetic. pass through fire 1 0r 2 more times quickley then Quench .make sure clay is applied evenly to both sides of blade. If not blades can warp . The optimum temp is 100 degrees difference between edge and spine , this produces what is commonly referred to a double hamon , . Temp is very critical even application is real important as is even heating , thats why I HT in early morning or at dusk so I can see there are no unevenly heated spots . The japanese call is Ya-kire . Also make sure quench medium is even temp , dont stir quench material with blade , stir before quenching. My sensei cracked me in the head for stirring quench with blade , he says it causes uneven quenching !! There are many ways to harden steel , In fuedal japan there were 5 major schools , they all thought thier way was the best . I am sure there were many disagreements , funny how some things never change .
 
Josh Dabney said:
Kevin,

Thanks for the reply !

I forgot to mention that I'm currently quenching in the metal 5 gallon pail the oil came in so I do have plenty of room for agitaion. I quenched tip down and used the cutting motion.

Thought I'd ask if your using the Rutlands brand cement ? I shopped for it locally a long time ago with no luck but will order some and give it a shot. I did pick up a caulking tube of some other brand of high temp stuff and tried it on a couple knives but abandoned it once I got satanite. The stuff is pink and it puffs up like a balloon when heated then all the puffy stuff burns off and leaves a very thin coating stuck to the blade that stays till ground off. I'm curious if the Rutlands cement reacts the same way to heating as this stuff ?

Thanks again for the reply, Josh
Click to expand...

I used a great cement from Worcester Brush co. years ago, but it vanished some time ago, now the Rutland black seems to be the best replacement. All these cements will "puff" if you place them in heat while wet. Apply the cement and wait a few hours until the stuff sets a bit, it does not have to be bone dry but it is the moisture boiling out of a goopy skin that then crusts over in the expanded shape that is causing your problems. When applied properly my experience and some testing revealed several reason why I like furnace cement more than satanite, ready availability being just one of them. Tenaciously staying on the blade was always a plus for me, but with careful application I have been able to pop the stuff off in one even sheet with a tap from a wooden block immediately after the quench. Bubba-san is correct to point out that agitation in the wrong direction can be a problem, with clay or without, you should never stir the oil with the blade, agitation from flat to flat will be very uneven and promote warpage, agitation should be in the most even direction, tip to tang, or a cutting motion from spine to edge.
 
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