Photos posted for Jeff Sanders

WOW!

Excellent, Brother Blade. Merry Christmas, Bro. Old Jeffro's out this way for the holidays--we'll take good care of him for y'all out there in Tuscon. Although y'all will probably have to thaw him out when he gets home--it's cold here!

Hey Jeffro. Y'all ought to bring the Blue Ridge Tribe to Tucson with ya , sos they can thaw out too. It's a full moon Sunday night and we be banging on some "enchanted" steel.

I understand the general idea of using clay to get it, but I'd like some more detail on how you use the clay.

-does the clay have to be dried out before heat treating the knife, or can it be used wet?
-does the wavy line result naturally, or do you sculpt the clay to make the line whatever shape you like?
-how thick is the clay on either side of the knife?
-what kind of clay do you use, and what kinds might also work?
-do you leave the clay on for tempering, or is it removed first?

Thanks for your answers. Happy New Year!

In the past, I've used refractory paste to achieve a unique temper line on my blades. Sometimes it comes in a tub already in a clay-like form, and sometimes it comes powdered, and has to be mixed up with water before use. One product (if it's still available) that worked really well, was a brand called "Satanite." No kidding. It was a refractory paste widely used to repair firebricks inside of woodstoves. Many of these products can be purchased at stores that sell woodstoves, firebricks, etc, as it is highly heat resistant. The Satanite could be used wet or dry, however with any individual product, I'd recommend experimenting before using it on something designed to be a finished item. For the kinds I had to use dry, I just put a coat on before I went to bed at night and by late morning or lunch time the next day, it was ready to go into the forge

Rob Hudson told me once, and I've stuck with this method, to make a thin slurry (the consistency of paint) and paint a light coat on the entire blade. When dry, mix up a thick paste (do it won't run) and coat the back or spine area of the blade with about a 1/4" thick coat, tapering down to nothing on the cutting edge. Or bring the coat down to the cutting edge, then scrape portions away from the edge with a popsicle stick to leave a nice pattern. Heat and quench when the edge is at critical temp. Then clean the blade and temper without any paste on it. Upon sanding to the higher grits, the hamon or temper line should become visible. If not, try a light etch with 3 parts water to 1 part ferric chloride (circuit board etchant from Radio Shack.)

There are different techniques and mediums. Find one that works for you and then share it and the results with us.

By the way, Rob Hudson quenches in around 400 degree F oil, so that when all is said and done, the blade is hardened and tempered all in one shot. His work is exquisite, if you haven't seen it.

Then the secret is:

A) The clay keeps the rest of the blade from reaching critical heat, therefore not hardening as much as the edge (which is exposed), creating the line;

OR

B) The clay keeps the covered blade hotter, longer, producing an almost annealed back, but hardened and possibly tempered edge (assuming the whole blade reaches critical before quenching).

In the end, the result is similar: the edge gets hard, the back does not. The clay either keeps the back from getting too hot or keeps it hotter longer... any insights which is correct? Which produces the line? And, in this vein of thought, would not a good edge quench also produce a good line if the only requirement is to harden one part and not another?

Methinks I'll have to play with this soon...

I think your headed in the right direction in your thinking, Chris. I go for the edge quench idea anyway. Also, it should be mentioned, that steel type plays a part in good temper lines. 1084, 1095 and W1 show real nice temper lines as they are low alloy steels. O1, 5160, 52100 and other more alloyed steels don't show them very well in my experience.

Never gave it much thought about whether the clay keeps the back cooler or hotter longer, but I'm guessing it keeps the back from getting to critical temp, thus not allowing it to harden when quenched. Either way--it's food for thought.

What's file steel again? W2? How does that work? I got a whole armload of them this summer from Wayne Goddard, where I also got his recipie for goop quench.

So I'm thinking, if files give good lines, I'll use my Marine Clay my house sits on (strained to get rid of rocks), to a medium thickness, semi-hardened on the back of the blade, leaving the edge bare. By semi-hard, I mean the consistancy of play-dough: just enough moisture to both keep the clay flexible, and the blade cool by the water's absorptive properties. Then, when the edge is critical or a little above, I'll jam it into the goop for an edge quench, leaving the clay-covered portion out of it altogether.

When I get around to it (another question for another day) I'll let you know how it goes. Meanwhile, I gotta start preparing to teach 40 boy scouts the new metalworking merit badge, which goes way beyond the tin can art of yore. Read all about it at www.usscouts.org/usscouts/mb/mb074.html

Happy Hammering!

What, exactly, does the word "Hamon" refer to? I'm assuming it's a foreign word; what does it mean? The difference between hard and soft? The word that means 'line'?

Inquiring minds want to know. Thanks. Time to go home and pound steel.

I did a merit badge thing with the Scouts many moons ago. Fun stuff. The clay keeps the back of the blade hotter longer and slows down the quench. If the clay is put on thick, like 3/8ths of an inch, the hamon line will follow it exactly. If thin,like 1/8 of an inch, it makes it's own line randomly! Also, thin clay gives a wide line and thick clay gives a thin line. I use a mixture of ground ceramic insulating wool, crushed charcoal powder, and kiln cement (sticky clay). The clay stays on through the hardening and then I remove it before the temper. I've only done about 12 or so, but they all turned out pretty nice.

So the entire piece of steel reaches critical, and the clay simply prevents the quench? Excellent. Does the hot steel also provide something of a temper to the hardened steel if the quench doesn't last too long? Or should I temper the whole thing anyway?

Your clay is then semi-wet when put into the fire, or do you let it dry completely first?

I'm getting giddy with ideas.

O.K., Tai, how about this:

Can I make the clay somewhat thick (3/8") and run it from tip to guard in an irregular pattern, creating a hamon with a distinct shape? I'm thinking a zig-zag thunderbolt, swirling ocean waves, puffy clouds, all in my steel.

I guess what I'm really asking is: will a highly irregular hamon line affect the strength or performance of a blade?

I also understand that such an endeavour would require a liquid quench medium, as opposed to Goddard's Goop (in solid form).


One last question (for now, at least!): On your knives, specifically the one above, to what point do you finish it before heat treating? Hammer finish, 600 grit, mirror polish? How much do you leave 'till after tempering?

I love this. I'll never stop asking questions. And maybe, just maybe, I'll get a computer at home with a digital camera so I can share more and more. I gotta get good first, though. Thanks for all of your help, everyone!

I'm not sure exactly what hamon refers to. There is a "line" between the hard and soft sides. I guess that is what I'm talking about, the "transition zone". That is where the cool detail is. I usually quench horizontal, so the back never goes under, but the part where the clay meets the steel does. Then I hold it there for a few minutes and let the whole thing go in. The clay mixture I use only needs to get leather hard, then you can pre-bake it, or put it right in. The ceramic fiber wool helps a lot with any kind of thermal shock, or cracking. I usually pre-sand the blade before heat treating, but only to a coarse grit, like 100 or so. A smooth file finish is fine. You need to take the blade down a bit after heat treating anyway. When I'm dong a clay temper line I stick with the 10 series steels. I like 1065 in particular. Some high alloy steels don't take a temper (quench) line very well, it just doesn't show, or is hard to get to show. It doesn't work so well on 5160. If you put the clay on thick, in a zig zag, lighting bolt pattern, or whatever, I believe you could get it to follow. I've never tried it, but I thought of it also. There are several other factors. The thickness of the steel, quenching temp, and medium, but if you did it all just right, then yeah ... I think so. I've been using vegatable oil which still gives a fast quench with a bit less shock. If you want you can thicken the vegetable oil for a slower quench, just by pouring it in a shallow pan and letting it air dry. It gets as goopy as you want.

Thanks again, Tai, for all your helpful insights. I will try to work up an experiment this weekend (including new years!), and let you know how it goes. For quench, I think what I'll do is just heat up a bar and melt down Mr. Goddard's Goop so I have a nice, hot liquid to dip in when I'm ready. Any final thoughts on file steel (W2, I think) as far as transition zone visibility goes? I use what I have, and I have a boatload of files to be pounded down.

I'll keep you informed, probably start a new thread... Gotta get some sleep now.

I've never used file steel, but I've talked to Don Fogg about it. He has done the nicest ones I've seen. I think he uses 1085 mostly. Anyway he said to normalize it (!095 or file steel) several times first. I would recomend cooling it extra slow. If you heat it up in a thick walled pipe, and let the whole thing cool in the forge, it works good. The idea is to compleatly soften the back first. Also because of the high carbon, don't quench it more than a five count, five seconds. Then lift it out for just a moment and return it to the quench. I guess it can actually fracture along the temper line, with 1% carbon alloys. I've used railroad spikes, with good results. The type of steel plays a key role in the temper line itself.

Man those are sweet! Nice work Flame! Very Nice!

Alex