Thread: Meat cleaver restoration

i am impressed at what i am seeing... i never thought to expand restoration to a cleaver or other blades.

Originally Posted by cjglancy

i am impressed at what i am seeing... i never thought to expand restoration to a cleaver or other blades.

I am also working on restoring an axe that I inherited from my grandmother, and which is very special to me for several reasons. I restored the handle as well as the axehead, to keep it as complete as possible.
Anything can be restored. I just like sharp things so I invest my time in knives, razors and axes. My mother restores antique books (300+ years old) we regularly show each other our works in progress and talk about how to do certain things. Some of the restoration issues are surprisingly interchangeable.

Ok guys, this is the santoku blade after grinding.
My inexpert mauling of the steel during forging left a couple of dents in the blade (not really visible in the pic due to lighting) but overall the result is nice.



Tomorrow I'll be claying the blade for heat treatment so that it will have a hamon.

Looks very serviceable...

I hope I'm not blundering into some awful punch line, but have to ask: what's a hamon?

Originally Posted by roughkype

I hope I'm not blundering into some awful punch line, but have to ask: what's a hamon?

Hamon 刃文 is a Japanese word for temper line. The literal translation is something like 'Cutting edge writing'.
If carbon steel is heat treated, it can happen that one part cools much faster than the other. If this happens, the quickly cooling part hardens completely, and the other part simply cools down and remains 'soft'.

Where the hard part and soft part meet, there will be a visible 'flaw' in the metallic structure.


Among blade enthusiasts, this is considered a desirable aesthetic. With swords and knives, there are functional advantages as well. Not only will it define the mechanical properties of the sword, but also how prone the edge is to chip, how any damage would spread, etc. For kitchen knives it is purely aesthetic. With cheap blades and swords, this is sometimes faked by etching it on. A real hamon is visible even if you'd polish the steel, though it is usually highlighted by careful manual polishing and soft acids.

The effect is controlled by coating a blade with a thin layer of clay before heat treating. The clay protects the blade from scale forming. Then, the part that has to stay soft is coated with a thicker layer of clay. Where the 2 meet, the hamon will form. Based on how the line between the 2 is shaped, different hamon patterns can emerge, and there is actually a large amount of identifiable patterns.

I have always thought of the hamon of a sword, knife, or razor the inner beauty of the steel.

Wow. Another reason for amazement at what clever monkeys we've become.

And it's a relief to know a hamon is nothing like a daugwhay.

Ok a quick update.
I clayed the blade, and performed the heat treatment when I finally had my forging setup working.

Here is the blade with the clay coating:


Here is the blade after heat treatment:


And here is the blade after grinding and polishing.
It is extremely difficult to capture it properly, with the blade surface not being flat.
Also I am not yet happy with how the polishing has turned out. It is serviceable, but I am not yet satisfied. Up to 1K, the hand polishing was ok. After that I tried a BBW and a coticule, but those are really not great for Japanese style polishing. After that I tried poliching compounds on wood, which was somewhat better, but that destroyed the hazy finish I was trying for.
I dipped it in light etchant to highlight the hamon.

I also cut several fingers in the process of polishing and etching


Now I still gotta figure out how to cut the handle, and also how to get the polishing done right.

You can get a good result going up to 2k with wetndri & WD40. Then switch to some Hazuya stone to polish the hamon area . No real need to use Jizuya as it is mono steel. If you have an uchiko ball you could use the powder on paper with a little oil to polish the same area.
Repeated light acid etching & subsequent polishing can yield a pleasant enough effect too.

btw . Lookin' good