clay just fell off my knife in the forge in one single chunk

J

JZknives

Joined
Feb 7, 2013
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204
Trying to do a hamon on w1 and had the clay on thick. I dont think it dried fully but it seemed hard enough.

But ya it just fell off like in one single peice like it wasnt even attatched. Also the refractory ballooned up to maybe twice its size.

What did I do wrong?

im using utility wonder do all plus refractory cement.


for further clarity i did put the cold knife with clay into a the forge when it was up to temprature
 
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If it's wet, the water steams off and blows it off the blade.


If it bubbles and balloons up, are you using furnace stove cement ?
Look into Satanite
 
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My guess is it still had moisture in it. I let it air dry to where it feels hard, then place it in the oven (Spine Up) at 250F for 30 min. Then pull it out and continue with your HT Plans.
 
I'll give my two cents worth, but I have to let you know I've still got the same problem going on. Like others say thin is in. Try not to put a ton of clay on the blade a little dab will do ya.

Second I've never put dry clay in the forge and at times I've had to scrap both sides off with a knife, it was stuck so tight. The only thing that I've found for the clay to really stick, is to have the blade absolutely clean. I've had the best luck with cleaning the blade with asesitone (not sure on the spelling), then followed up by cleaning with dawn dish soap. If I miss a spot this is were the clay will come off.

In short clean blade, but drying might help. I've never tried it my clay has always been wet going in. Let me know if any of these hints help. But I'll stand by thin on the clay is better.

Dave from Diller
 
Interesting Dave. I think the brand of clay you use plays a big part in how to deal with it Pre-HT. I started out with Satanite but have now moved to Rutlands and like it much better.
 
RyanW said:
Interesting Dave. I think the brand of clay you use plays a big part in how to deal with it Pre-HT. I started out with Satanite but have now moved to Rutlands and like it much better.
Click to expand...

I agree Ryan! I've recently tried rutlands and love it!! The texture makes it alot easier to control where you put it
 
Ugh now you guys are making me feel bad for not getting rut lands. :(

Just wanted to support local and they had no rutlands.
 
All this reminds me of a member here ( who shall remain nameless) who tried to do his first clay-coated blade in 1095. He had the clay fall off, and sent me an email about it. He was using red clay from the field behind his house. I suggested he get some Satanite and gave him instructions for putting on a light wash coating first, drying that, and then putting on a fairly thin layer where he wanted to slow the hardening. He did this and dried the clay for a day before HT. After the HT and quench, the clay was still solidly stuck to the blade. He was so excited that he wanted to see how the hamon looked.....so he took a hammer and hit the spine to knock off the clay.....bad idea!
 
I'm with Dave on this one.

Clean the blade with Soap and water. Critical!

Thin clay, Satanite works best for me. Most hamon activity!

Apply clay and straight to the forge. No need to dry clay before heat treating.

In close to 10 years of hamon work, I've never let the clay dry before heat treating. Never had a problem either.
 
I obviously need to try a few things! thanks for the pointers Don.
 
Or just don't use clay... ;) :p

I'm with Dave and Don... the blade needs to be CLEAN. Dish soap and hot water work for me.

I dry the clay with a propane torch (just like browning meat in a skillet... but with clay and a torch ;) ) I don't do it so much for keeping the clay in place, as for protecting it for when I bump the blade into something. It takes about a minute to do it.

I like Satanite, but I think I have some furnace cement somewhere... might have to give it a try and see how it goes.
 
k I just tried again and while it adhered a little better , the clay still bubbled in the forge. When i dunked it in the oil the clay completely came off.

But the area which i "cleaned" where the hamon and open steel was had a thin wash of clay on it (because i couldnt scrape it all off) still had clay clinging on.

and this leads me to believe what bldsmith said was true , that you should first do a wash coat and then let that dry and then another coat after that.
 
Do you mean it had clay sticking on it from the first time you quenched it? If so, then that clay would be holding oil and mess up your second attempt.

Here's a more detailed explanation of my approach:

I grind to 50X. Smooth any sharp edges with a 120X J-flex belt. If I have any Dykem or marker on the blade I clean it off with Acetone. Then clean the blade with hot water, Palmolive, and a paper towel.

My first coat is a "wash" of very watered down Satanite, put on with a el-cheap-O paint brush. I buzz over it with the torch or heat gun so that base coat is dry. For me, this coat is extremely thin... as in there's hardly any of the sandy grit from the Satanite in it. It looks more like paint. And that's how I think of it, as a primer coat.

Then apply the body of clay and ashi lines. Very little clay here!

I put the blade in a vise, tip up, and brown the clay.
 
NickWheeler said:
Do you mean it had clay sticking on it from the first time you quenched it? If so, then that clay would be holding oil and mess up your second attempt.

Here's a more detailed explanation of my approach:

I grind to 50X. Smooth any sharp edges with a 120X J-flex belt. If I have any Dykem or marker on the blade I clean it off with Acetone. Then clean the blade with hot water, Palmolive, and a paper towel.

My first coat is a "wash" of very watered down Satanite, put on with a el-cheap-O paint brush. I buzz over it with the torch or heat gun so that base coat is dry. For me, this coat is extremely thin... as in there's hardly any of the sandy grit from the Satanite in it. It looks more like paint. And that's how I think of it, as a primer coat.

Then apply the body of clay and ashi lines. Very little clay here!

I put the blade in a vise, tip up, and brown the clay.
Click to expand...

The hamons I've seen from you without clay have been the best I've ever seen! Period! I need to take a stab at the no clay method. :)
 
I pretty much do what Don and Nick recommend except I cant do the no clay method theres no way my forge could maintain the exact temps required to do that. A thin wash like Nick said. I usually dont let that dry though, more with Don on that area. I then lay the thicker stuff and lines or whatever I want to do. Then its into the forge. I do one last normalizing cycle (well my normalizing cycle) with the clay so by the time I am done its good and hard.

I have noticed the only time I have it pop off is either I dont clean it well before hand (will have a good amount come off every time and I kick my own butt for that), or I am quenching in water. The water since its so well excited can sometimes know the clay off after the first few seconds of quench. Usually this wont affect the hamon too terribly much but it still can. Depends on the blade profile and thickness.
 
I recall having this problem when I first started trying to differentially harden some trial blades - and actually started out with a mix of gray clay from the frontyard and other additives I'd heard about such as coal shavings and powdered rust. Like you said, it busted off the moment it made contact with the brine. As you can imagine, I'm done trying to "attempt mixing at home." While I have yet to find and purchase this Satanite refractory I hear a lot about, I am very satisfied with apg#36 cement. I believe another smith, Bob Engnath uses it to produce hamons. It's quite incredible, I have even done a test-run with a still wet coating, and while it puffed up a bit once inside the forge, it stayed on...STAYED ON! :eek: :D

Also, like with most other materials for claying / hamons, I recommend following NickWheeler's advice about cleaning before coating. It will make a world of difference regarding how well the clay stays on.
 
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