Clay coating

H

hawkwind

Joined
Oct 26, 2004
Messages
298
Hi folks,
as I forged myslef mighty seax few weeks ago, I want to diferentially harden it now. O have found very good quality high temperature mortar clay, which I intend use fo blade coating.

Can somebody advise me on thickness of clay coat on hardened and non hardened area?

Jaroslav
 
hawkwind said:
Hi folks,
as I forged myslef mighty seax few weeks ago, I want to diferentially harden it now. O have found very good quality high temperature mortar clay, which I intend use fo blade coating.

Can somebody advise me on thickness of clay coat on hardened and non hardened area?

Jaroslav, No clay is used on the sections of the blade you want to harden.
The thickness of the clay on the areas that you want to be "unhardend" is best found by personal expermentation. The clay is put there to slow the cooling of the steel so no hardening takes place in the areas where the clay is applied. Heat the clayed areas first, from the spine side, edge and point last.
When you have the entire blade up to critical, quench the whole blade.
If possible, coat the entire blade with borax. Heat the blade slowly just untill the borax sticks to the surface. Then heat the blade until the borax runs over the surface. Let cool, apply the clay, then harden This is the way I clay harden. I'm sure ther are many other ways. Good luck Fred
Start with 1/8th inch thickness of clay and adjust from there.
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Another way to apply the borax, is to make up a slurry of borax and alcohol. Not to thick though. Then, brush the mix on the blade, once done, burn off the alcohol (just takes a few seconds) and the blade is now coated. Learned this trick from Jeremiah Watt, spurmaker. He does this before silver soldering (with high temp stuff).
 
Good idea, I'll be giving this a try. Thanks for posting. I love these forums. What a great source of info. /Fred
 
Interesting idea on the borax, never heard of that.
 
Fred and all, thanks very much for your inputs!!!

Suppose that borax is there to clay stick on the blade?
 
hawkwind said:
Fred and all, thanks very much for your inputs!!!

Suppose that borax is there to clay stick on the blade?
Click to expand...
The borax keeps oxygen away from the steel surface. This prevents decarburazation or loss of carbon from the steel. Let us know how it comes out. Fred
 
I am assuming the borax you guys refer to is not the 20 mule team detergent and if so, where do you get non-detergent borax??
 
from what I've heard it can be used( the 20 mule team).
Forgot wich site I saw it on, but someone was welding damascus wit it.
 
I've got a question about the borax. I just heat treated my first blade and I got terrible scale on it with pitting. Will the borax help with this during normalization and hardening? I need to figure out a way to prevent this because im going to have a ton of grinding to do to remove the scale and pits and dont want to do it on future knives. Thanks!
 
FlaMtnBkr said:
I've got a question about the borax. I just heat treated my first blade and I got terrible scale on it with pitting. Will the borax help with this during normalization and hardening? I need to figure out a way to prevent this because im going to have a ton of grinding to do to remove the scale and pits and dont want to do it on future knives. Thanks!
Click to expand...
Add borax anytime you want to protect the surface of the steel from oxidation.
If I am normalizing I use a grinding wheel to remove surface scale. I'm not that concerned about the steel surface at this stage. When making a bar of damascus, I may grind the surfaces 6 or 8 times. when the blade surfaces you want to grind, after hardening, are "set" this is when an application af borax will give you the most benifit. It will reduce, surface scale and pitting dramatically. You don't have to be using clay and borax as a team,. It works to protect the surface of the steel. The easyest way that I have found to apply it to the blade, Is to lay the heated blade<one surface then the other, into a pile I have close to the forge. Apply heat to the blade untill the borax runs over the surface After you harden the blade,
use a brass scraping tool to clean the surface of the steel. Fred
 
how does borax compare to brownell's no-scale compound?
 
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