Yanagiba Repair

[VICTOR J CREAZZI]

This video shows a chip repair on a yanagiba;


The chip clearly goes deep into the concave area of the ura. Since all of the initial metal removal was done from the bevel side, I cannot understand how this could not result in a twist on the repaired knife. I recently helped Dafox with a profile issue on a yanagiba and though I was working on the spine side I was very carful about not going into the concave region because of this concern.

I thought that possibly the anvil work in the beginning was to pre address this resulting twist, but it doesn't seem like enough was done. Maybe this is addressed in the text, anyone read Japanese?

 

[Blank Blades.]

The anvil work in the beginning was to remove any warps that are already apparent in the blade.

It doesn't matter much for him grinding down the blade. Because he uses that huge water wheel, he is able to create a new ura (concave portion).he reground the whole thing, the hira (blade face), ura, and the bevel. Basically doing it almost like he was making a new knife.

 

[VICTOR J CREAZZI]

My approach would be to establish the new plane of the ura first, avoiding introducing the twist at all.

 

[zizirex]

AFAIK, those chisel tip hammer helps to maintain the ura. it helps spreads the steel in the right direction.