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- Jan 26, 2002
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- 2,737
Some may recall a prior thread about the bowed horn slabs on a JKM-1 I have. I'll summarize what I found:
Steaming the handle then clamping for about 36 hours in a small vice did reshape the horn. Unfortunately, I tried the replace aluminum pins with sections of filed brass bolts (filed down until just a bit of the thread remained) and one of the slabs very easily popped off. Removed the other slab and sanded/filed tang and slabs to provide a good gluing surface.
Now the fun started. I was quickly became apparent that none of the holes lined up, and some were drilled at slight angles. The holes in the tang look to be hot-punched, and were not filed. They are out of round and oversized. With the soft aluminum pins, which seem slightly undersized, it's possible to force the pins through the crooked path, but I suspect that the laha is what holds things together in a case like this. Dunno if this is typical construction or not.
So I evetually got the holes reamed out so that things fit together with my straight brass pins. O course there were some gaps, and with the poor fit of the holes, things were not held in alignment by the pins. How to glue this up?
I carved some temporary pins out of wood and left them a bit short on purpose. I was able to shape and force fit them to hold things in reasonable alignment. Glued it up with copious amounts of JB weld, and clamped it up. Sanded down a bit of a black dry chalk pastel stick to darken the glue--should have used more.
After cure, I carefully drilled out the wood pegs. I used several sized sharp bits in a mandrel and did it by hand. Too easy to slip with a power drill and hard to clamp the round handle. Not hard at all since there was no metal to be removed. Slightly reamed the slabs to accept pin rivets, glued in the pins, and peened them out after the glue had just started to set. The slight threading left on the bolts should hold the glue, which has also filled any gaps, and they took a bite on the tang. I got good expansion on the pins that pretty much left no gap on the surface of the handle. Don't think those slabs are coming off, ever.
Using the temporary softwood pins made things a lot easier, at least for me. But it adds at least an extra day versus trying to do it all in one step.
Steaming the handle then clamping for about 36 hours in a small vice did reshape the horn. Unfortunately, I tried the replace aluminum pins with sections of filed brass bolts (filed down until just a bit of the thread remained) and one of the slabs very easily popped off. Removed the other slab and sanded/filed tang and slabs to provide a good gluing surface.
Now the fun started. I was quickly became apparent that none of the holes lined up, and some were drilled at slight angles. The holes in the tang look to be hot-punched, and were not filed. They are out of round and oversized. With the soft aluminum pins, which seem slightly undersized, it's possible to force the pins through the crooked path, but I suspect that the laha is what holds things together in a case like this. Dunno if this is typical construction or not.
So I evetually got the holes reamed out so that things fit together with my straight brass pins. O course there were some gaps, and with the poor fit of the holes, things were not held in alignment by the pins. How to glue this up?
I carved some temporary pins out of wood and left them a bit short on purpose. I was able to shape and force fit them to hold things in reasonable alignment. Glued it up with copious amounts of JB weld, and clamped it up. Sanded down a bit of a black dry chalk pastel stick to darken the glue--should have used more.
After cure, I carefully drilled out the wood pegs. I used several sized sharp bits in a mandrel and did it by hand. Too easy to slip with a power drill and hard to clamp the round handle. Not hard at all since there was no metal to be removed. Slightly reamed the slabs to accept pin rivets, glued in the pins, and peened them out after the glue had just started to set. The slight threading left on the bolts should hold the glue, which has also filled any gaps, and they took a bite on the tang. I got good expansion on the pins that pretty much left no gap on the surface of the handle. Don't think those slabs are coming off, ever.
Using the temporary softwood pins made things a lot easier, at least for me. But it adds at least an extra day versus trying to do it all in one step.
