Hiromoto bolsters - how are they attached? How is the blade hardened?

[Mike9]

I got a 270 Hiromoto Gyuto delivered yesterday and took the handle slabs off today. They shrank and you could feel the sharp edge of the tang. I intended to do a Yo rehandle on this, but if the blade and tang are not hardened I might can band saw the bolsters off and convert it to Wa. Any idea how they are attached - looks like solder, but very clean with no big puddle.

[ThEoRy]

I've heard of people grinding bolsters off.

[SpikeC]

Why not reshape the bolster into wa shape?

[Mike9]

I see brown on the tang behind the bolster now so it's seen heat. I emailed Adam Marr and he concurred they are welded on. I may be doing that Yo rehandle after all.

[Dave Martell]

The bolsters are definitely welded on and the tang will be partially hardened at (around) the first pin hole at least where the ass end is usually soft and pliable.

[Mike9]

Thanks Dave - I was looking at the first one on page 41 of your gallery and that seems like the best of both worlds. The one you bobbed the tang on with the ironwood handle - that was a smooth move.

[Dave Martell]

Thanks Dave - I was looking at the first one on page 41 of your gallery and that seems like the best of both worlds. The one you bobbed the tang on with the ironwood handle - that was a smooth move.

That's sure easier than grinding the whole blade after grinding the bolster off plus you could still go wa and leave the bolster, maybe incorporating it into the handle shape.

[kalaeb]

You could do a radar esk handle like the kikuichi in the twin cities meeting thread.

[Mike9]

I went partway in that direction. I cut the top of the tang down then cleaned up around the bolster. I got this tremendous block of ironwood burl with sapwood running through it. Unfortunately it was on a corner. I had to make a jig to bandsaw the block in half diagonally. Then I rabbeted both sides to go around the tang then traced and cut around the back and bottom of the tang and epoxied the whole thing together. After it set I started stock removal and shaping the handle before polishing it and the bolster. Then I rounded the spine and choil, thinned behind the edge, polished that and sharpened to 6k followed by stropping. Then I got the idea to shave some carnuba wax and mix that with some sweet almond oil and apply that to the handle, warm it with a blow dryer and buff. Spectacular shine now.

It was a difficult glue up and while shaping the top of the handle revealed the glue joint as a dark line. oh well I have an idea for next time, but it's still a great looking and feeling handle. This knife by the way could well become a favorite - the geometry is excellent, the blade is thin and the AS takes a wicked sharp edge. It looks odd on the bar next to my long handles, but the balance point is an inch ahead of the bolster now - (much better than stock)