View Full Version : Clay for Hamon need some help

05-07-2011, 06:48 PM
I am about to do a blade out of some w2 I got from Aldo and the customer wants a hamon on it. I am new to this but am willing to give it a shot. What do I make the clay out of for this? What materials do I need to get and where can I get them? I am also planning to use parks 50 but have been told to use salt brime which will do better?

05-07-2011, 07:10 PM
gahagen theres a great tutorial on hamons in the tutorial section, on that note i think the parks would be very good, i use furnace cament from true value. good luck,and hope to see how it turns out.

Rudy Joly
05-07-2011, 07:30 PM
The furnace cement has worked just as well as the satanite for me. The Parks will work and is safer than the brine. If it's a thick blade, I found going a little higher than where you expect the hamon line to be is good because of heat bleeding down from the thicker protected spine. It took a few tries to outsmart the thing on the first few blades. Good luck.


05-08-2011, 05:43 AM
I have a little recipe that works well, satanite and crushed powdered activated charcoal . 3 parts satanite 1 part activated charcoal. Rudy is right dont attempt a water quench if this is your first shot at doing a hamon ( japanese translation is "ripple ring on the water " it also means creamatory . If you do try water only use a 4 sec. quench any longer and you may have cracks. Usually on medium and small blades you dont have to worry too much, the water should be about as hot as it comes out of faucet so its not too much of a shock , traditionally a hamon should be about 1/3 width of blade on a sword , on smaller blades you can get pretty artistic without too much problem .Try and apply clay evenly on both sides of blade , uneven application may cause warping But, honestly aldos new W-2 Low manganese and parks 50 does a heck of a job. The thicker the clay the more differential hardening you have but, the more chance of cracking or warping . Contrary to what a lot of folks believe , a hamon is not a temper line , it is a hardening line , tempering is a much different process. Also when you do temper on a differentially treated Blade, especially on bigger blades. Keep your tempering as short as possible , heat is the biggest enemy of a hamon . Most true japanese smiths use a flash temper , which is about 200 degrees for about 10 -15 minutes and that is done right on some hot coals, just keep blade moving .The reason is the mune ( spine) and blade above hamon is already softer than the edge by 20 points or so on the RC scale. I am talking about large blades generally. good luck . ..... Bubba

05-09-2011, 09:08 PM
I have used satanite, mainly because I already had it around for forge construction.

I have a little recipe that works well, satanite and crushed powdered activated charcoal . 3 parts satanite 1 part activated charcoal. ..... Bubba

I have heard of mixing with crushed charcoal before, but have yet to try it.
What benefit does this have? And what adjustments, if any, are required during HT?


Kevin R. Cashen
05-10-2011, 06:19 AM
I am about to do a blade out of some w2 I got from Aldo and the customer wants a hamon on it. I am new to this but am willing to give it a shot. What do I make the clay out of for this? What materials do I need to get and where can I get them? I am also planning to use parks 50 but have been told to use salt brime which will do better?

I just got back from another weekend hammer-in at Rick Barrett's so as with every time I get back from Rick's I have Japanese blade overload. Well not really since I normally do my own thing and just observe the Nipponophilia around me, but anyhow... the American katana makers whose work impressed me the most all like furnace cement, it is convenient, easy to work with, readily available and highly effective. I have done side by side tests with furnace cement and satanite and found adhesion and insulative ability in the furnace cement to be much more to my liking. Furnace cement ashi have given me and others very crisp and defined hamon activity. Whomever's advice you take be certain not to mix and match advice from water quenchers with oil quenchers. You will need slightly different clay application and temperatures depending on what you are quenching into. For water you will have to take the low side on the heat and apply the clay more, for oil you will go higher in temp and take it a little easier with the clay (e.g. no slurry washes, and keep ashi off the very edge).

To be honest Parks #50 is the only oil that I would say can completely replace water for hamon. It will harden very effectively and produce very nice activity without the threat of cracking or warping the blade, even the guys who are really good must accept losing some blades to water. Guys like Burt Foster and Don Hanson are getting some of the most stunning hamons you have ever seen on bowie knives using Parks #50. Many years ago I talked Rick Barrett into giving Parks #50 a try, and after a short period of adjusting from water he loved it and now does all of his swords in it. He has even impressed me with the results he has gotten, like nice tall, and defined choji hamon. Of courser since there are not the destructive stresses involved with the #50 you will also need to have your sori (curvature) applied before the heat treatment.

05-10-2011, 08:51 AM
Activated charcoal increases surface area many times, allowing more control over heating and cooling of blade . I learned this in Japan when I was stationed there in the 1960's Japanese clay is made from charcoal , clay,and pulverised sandstone in equal parts. Charcoal helps the smith adjust the rate of heating and cooling , it also helps the clay mixture bond to blade better. Blade is made from aldos W-2


Here is pics from hamon produced from home made clay mix and saltwater quench
Cutting edge this blade is approx 12- 13 " I wish I could take better photos , Hamon is very vivid..... Bubba

another smaller tanto using same mix on piece of 9260 silicon steel , not as bright but still nice . Quench was parks 50#

05-10-2011, 05:47 PM
How do you make the slatwater quench. I dont know if my parks 50 will be here in time. There is a back order on it.

05-10-2011, 06:27 PM
brine quench you mean??

saturate the water with enough salt to float an egg


warm the water to around finger ouchy hot and go from there


dude its a violent quench and I would wait if I were you

05-10-2011, 07:21 PM
well not exactly ,.close. it is salt water but I cut back on it so it will not float egg but, works wonders on hamon, I make my water as hot as it comes out of faucet , just a little different but, effective none the less. Its not so violent a quench . Not for the lighthearted or a first timer . about 2 cups of salt per 5 gals of water . Dont quench longer than 4 seconds . Or you may hear the familiar "tink"

05-11-2011, 07:16 AM

Break the process down into "pieces".

Clay coating
Looks like everything is wide open concerning the clay coating used, sorta like everyone still gets from point A to point B regardless of whether they drive Ford, Dodge, or Chevy.:3:
For the first time doing this, your preference will most likely be determined by whatever is easiest for you to obtain.
If you decide to do more of this, you'll probably settle on a favorite.

Franklin mentioned the hamon tutorial by Stephan Fowler, and I think that is an excellent primer for anyone new to this- the pictures allow you to see the work in progression.
If you haven't visited that thread yet, it is worth your time to check it out.
Something I believe is very important is to be sure that the entire blade be covered. The area of the blade you desire to harden still needs an ultra-thin coating of clay.
On that note, I believe it well to consider Bubba-san's advice in post #4, in regards to applying the clay evenly on both sides of the blade. This is easy to do if you have a relatively simple, straight hamon. More complex pattern naturally makes this more difficult, but not impossible.

Quench medium
Water? Brine? Oil?
Yep, it's very confusing!:confused2:

I have only done 4 blades in this fashion, and all used a heated water quench. ("Heated" meaning hot water from the faucet.)
The second blade cracked on me, but I have to wonder how enlightened I would be if somebody like Kevin had access to the other three and "put 'em under the eye.":biggrin:
Nevertheless, the other three seem to have survived, but that just means I haven't done enough of them. With a water quench, the "masters" have at least 25% rejection rate, really "good" can expect at least a third or more, and newbies like us should not be surprised with even higher percentages of failure.
Point is, blades will be lost with this method. That's the downside. The upside is that if everything else is right, this method produces stunning hamons.

There are many methods people utilize to avoid the cracking problem associated with water/brine quenches.
Obviously, the edge cannot be too thin.
Others have their beliefs on temperature of the quench medium.
A very popular "fix" is an interrupted quench. Example- "In for 3 seconds, out for three. Then back in for three, back out for three. Then back in and stay until blade cools to water temp."
Still others use a "combination" approach. Example- "In water for three seconds, then out and straight into heated oil for remainder."

I will attempt a brine (saltwater) quench with my next blade, but I think I will keep the brine at room temp.
For more information as to why, check out this discussion:

Please take note that my limited experience with this is based upon these blades not being for others; they were simply "learning exercises" for myself.
And that, to me at least, is what will probably be your biggest obstacle- you have a customer that wants it, but you have no experience doing it.

Considering all the factors involved, the oil quench is probably the way to go if you can wait for the oil to come in. (I have never heard of anything "custom" that did not require some period of waiting.)
Whichever method you choose, it's always a good idea to have "spares on standby".

One final note, as you have not mentioned the type of blade you're trying to produce.
Kevin mentioned the sori (curvature).
The blades subjected to a water or brine quench will have a pronounced curvature. If you water quench, but do not want this look, you will have to anticipate and adjust for this. From what I gather, most adjustment is done after HT, as there is no simple way to determine exactly how much sori will be obtained.
Conversely, if you're doing an oil quench, and you do want sori, then you need to shape it into the blade.

Good Luck,

05-11-2011, 02:51 PM
I usually break about every 4 th or 5th blade when I water Quench. the upside is you can always make it into a smaller blade which is very traditonal .I am one of these smiths ,that knows all the processes but am not good at articulating it . I can show you much better . I hand forge all my japanese blade no grinders . Always remember of the five great smithing schools of Japan (Gokaden), they all had different processes , some of which are probably lost forever . They would stand around argueing whose was the best , not unlike today . Seems like some things never change. Ha ha. I also make my own Tamahagane when I can . Most smiths find their niche and stick with the process that suits thier needs and abilities . I have made a soshu kitae 6- 7 piece laminate sword , a style that was used by masamune . It turned ok pretty nice no breaks LOL.when Doing a hamon your sword is like an artists pallet , you never know what it's going to look like ?. The sori is normally adjusted on a copper block that weighs about 25 lbs . I do both kinds of quenches , and have had good luck with both . I mainly use water /salt because I was trained in the traditional manner and I have good luck with it. I rely on color and magnetism , and only do it at Yakire . early morning or right at dusk. so color is critical as is the state of magnetism ( fully non- magnetic) thats why its best to do quenches when light is low so you can see color variations which is so critical also, I wish you luck . you may PM me if you want to ask a question anytime. regards Bubba-san

05-12-2011, 11:32 AM
Well this was good info. I will give it a try. I have plenty of metal and may just cut out multiple blades so on will come out right.

05-12-2011, 02:37 PM
Good luck with it, and let us know how it goes!

05-12-2011, 02:54 PM
i forgot to add an easy way to get an even look on both sides is to do a reverse cutout and put on the bottom by the edge put your clay down then remove paper or construction paper whatever you use then do same on other side. it comes out super even and ive had no warps since.

05-12-2011, 03:07 PM
Thanks for that advise.

05-13-2011, 08:32 AM
Another good way is to mark the spine of your blade about every 1" or so with marker , that way you have a guide where you put your dips and curves and ishi lines . Also if you like to prevent too much sori is to not clay the mune ( spine) that way it hardens also,
and can pervent too much curve , and thusly cracking .Kind of like counters the blade wanting to bend upwards too much.

05-15-2011, 09:07 PM
I've started my knife-making last year using soley 1095 (Aldo's), brine quench, and clayed blades (furnace cement in the beginning since I had a metric ton left over from building my forge, but I changed to satanite in Jan 2011).

Here are some pointers I either learned eaither thru people like Stacy Apelt (bladsmth on bladeforums.com) or other extremely helpful people. A brine quench is not for the faint of heart - I lose 1 in 3 to 1 in 5. Imagine it, you spend ~10hrs grinding, filing, and sanding a blade only to have it crack during quench. Can be very depressing but at the same time it makes you really appreciate the ones that make it to the sheath-making stage of the craft! I would also suggest you do an advanced search on this forum and bladeforums.com for "hamon tutorial". LOTS of info there!

1) If brine quenching then coat the whole blade with a thin wash of clay (really watered down clay) and let it dry. This will increase the surface area of the blade and help cool it faster in the brine. A clay thickness of less than 1/16 to 1/32" will have no effect on the heat treat - meaning the metal will still harden during quench. The thin wash is meant to increase surface area and increase the rate of cooling. Note: for an oil quench in say parks 50 don't apply the wash. Leave it bare metal.

2) Clay basecoat - coat about 1/2 to 2/3 of the blade in an even layer of clay about 1/8" thick with the uncoated part running along the blade edge. Do this on both sides and let it dry. If you want (and i highly suggest it for a fisrt timer) just quench the blade with this layer alone. You'll get a suguha hamon or rather straight line hamon with no waves. My first few were like this and they looked great! The hamon will be either right at the edge of this 1/8" layer or slightly pulled up towards the spine a bit.

3) When you want some waviness or more activity in the hamon it gets a little trickier. You have to have the mindset that the clay doesn't "paint on" a hamon, but rather the clay is used to control the heat in the blade - which in turn controls the hamon line. The clay cools at a different rate than the metal does, so it actuall retains heat rather than shields the metal from it. Depending on how much heat is retainined determines if the cooling metal misses the pearlite nose and hardens or not. (If you don't know what the pearlite nose is then you need to look at the ttt graph for 1095. In order to get 1095 to harden, and hence miss the pearlite nose, you have to drop the metal temp from 1450-ish to 900 in less than 1sec). The larger the glob of clay you put on (larger glob = more mass = more retained heat) the further away the homn line will be pushed. You are trying to move the hamon line with heat and you do this by varying the amount of clay on the blade. The retained heat in the clay will force the metal under it to cool slower so you don't miss the pearlite nose - martensite will not form. I hope this makes sense. Remember, you direct where the hamon is by using heat...and the only way to do this is to use hot clay.

4) When you have you desired clay pattern on the blade let it dry. When the clay is dry use some thin iron wire (I use fastener wire used for wire-wrapping bolts ant whatnot) and wrap the blade with it. You don't have to go overkill with it, just one wrap every inch or so. This forces the clay to stick to the blade. Even with satanite I lost every blade that wasn't wire wrapped. The wire is good insurance that the clay stays where it's supposed to. Keep in mind that the rates of thermal expansion/contraction differ between the clay and metal. The clay, being more brittle than metal, will contract less so unless there's some kind of mechanical means of holding the clay to the blade (i.e. wire) then the clay has a good chance of sloughing off the metal in the quench causing the whole blade to harden - and usually crack in multiple locations!

5) When I heat up my blades for heat-treat I let the forge come up to temp first (1425 to 1470. I use a PID controlled propane forge that holds a temp setpoint to +/-10deg) then stick the blade in with the blade-side up, spine to the forge floor. I'll pull it out periodicaly to give it a magnet test to see how close I am to 1450degF. Once I hit 1450 I let it sit in there for about 5mins to make sure all the metal and clay is at that temp, then shut the forge off and let it dwell for about a 30sec to 1 min to make sure the whole blade is at temp and there aren't any variations.

6) While the forge and blade are heating up I'll drain off half my 5gal bucket of brine into a large pot an heat it on my range to 140degf. When it's about time to quench the blade I'll dump the pot of brine back into the 5gal bucket (which is usually at 70 to 80degf) to give me an end brine temp of about 100 to 110degF. You want your brine at 100degF min. BTW - as you're heating your brine go ahead and set your temper oven (in my case the bottom oven in the kitchen) to 400degF.

7) When you quench the blade use an interrupted quench. I'll stab the blade in blade-side down, point-first, and leave it stationary in the brine for a count of 5-mississippi, pull it out of the brine for a count of 3-mississippi, and then dunk it back in until cool to touch. Once cool don't try to check for a hamon or worry about cracks! (If you're lucky you didn't hear the dreaded "tink" of cracking metal). The only thing you should do is run to your temper oven and put the blade in. I'll use 1hr temper, air cool 30mins, then another 1hr temper. Some people won't air-cool but rather pull the blade out of the oven and cool it under a faucet, then stick it back in the temper oven again. Supposedly this is to increase the blade's low-temp toughness, but I've never tested this.

8) After the last temper cycle, and when the blade is cool to handle, go ahead and sand one side of the blade all the way to to 800grit (220g, 400g, 800g) and then etch for 15sec in 50/50 mix of ferric chloride and water. Pull it out, wash with windex to deactivate the etchant, and wipe with a rag. If there's a hamon you should easily see it! If there is then congrats and get started finishing the blade. If there isn't then try heat treating again after a good normalizing cycle or two, or if there are cracks then @@@@-can the blade and start again.

9) If I do hear that dreaded Tink then I may not neccisarily trash the blade. After tempering I perform a very crude equivalent of a magnetic particle test to find out where the crack is and determine it's size. If it's small I might be able to grind it out or make a shorter blade. Gather up a small cup of steel shavings from around your grinder and lightly dust the blade with them. Then take a strong magnet and attach it to the opposite side of the blade that you just dusted. Move the magnet around and, if there are any cracks, you should see the metal filings gather around them. Cracks in the blade disrupt the magnetic field passing through the metal. the filings will align themselves in a thin line along the length of the crack - showing you were and how long it is. It won't show you depth though.

10) This probably the most important tip. Prior to heat treat make sure you leave the blade edge at LEAST 0.040" thick and round off any sharp edges on the blade with 220 or 320g sandpaper. Sharp (90-degree) edges will create stress-raisers and drastically increase the chances of cracking. For an added measure of safety I usually take my blades up to 400g to make sure there aren't any deep surface scratches that could create a stress raiser.

05-15-2011, 09:25 PM
BTW - That tutorial by Stephen Fowler is EXCELLENT! (One linked in origional post). His tutorial was how I learned to apply the clay globs to direct the hamon. Examine closely the sizes of the globs he applies, how they're placed, and the spacing.

Here's a couple more thoughts on finishing the hamon. To really bring out the activity it takes a LOT of polishing (polish, ferric chloride etch, polish, etc,...repeat 30 to 40 times). For a working blade I'll take it up to 1200grit, etch once, polish with simichrome or flitz, etch again, and one last simichrome polish. At that point I'll clean the blade well, heat it up slightly with a heat gun, and apply a nice thick layer of carnuba car wax. This should keep the blade from rusting for awhile.

For a nicer blade I'll do a LOT of warm vinegar etches with a cotton swap applicator and polish with simichrome. Ferric chloride will make the hamon darker, and vinegar will make a white-ish hamon. I could probably make the hamon look better with optical grinding powders and whatnot, but I don't feel like putting +100 hrs into polishing a hamon on a blade. I might think otherwise if I had a really nice blade, but for now I've got too many other hobbies to maintain hehe.

05-16-2011, 03:17 AM
I used to use wire also in my younger days , thats an old trick .but, it does work . I dont use temp gauges ,I do by color and magnetism . I cant stress enough to do it in early morning or at dusk , so you can see color .I USE JAPANESE WATER STONES TO DO MY ETCHING . they are very alkaline and will etch blade without dulling finish. I have been doing that way for nearly 40 years .lemon juice will etch your hamon white , which looks more traditional. Doing a hamon on knives under 1 ft or less is pretty easy , once they get longer , like swords or large blades is where you can have some problems. I only use low manganese steels less than .25 or so . They will make the most dramatic appearance. I use 20,000 grit stone for finish but them babies is high , i use them in conjunction with naguru stone whick is also very alkaline and also increase cutting ability of stones. Time spent depends on what the customer is looking for and willing to spend !