Bolster WIP

Robert Erickson

Robert Erickson

Knifemaker / Craftsman / Service Provider
Joined
Feb 2, 2014
Messages
2,899
It's been a while since I've seen a WIP in Shop Talk and I've had a few people ask me how I do my bolsters so I thought I'd take a crack at doing a WIP.
I like bolsters for a number of reasons, mostly for the way they add visual interest to a knife. They also allow me to use shorter handle material that otherwise I wouldn't buy or be able to use.
I'll preface this WIP with this: This process is just one way of doing it. It may not be the best way or the most efficient way but it seems to work for me.

Most of my bolsters for a regular sized knife are in the 1 1/4" range but that is just personal preference. Initially I'll use a piece that's a good 1/2" longer than intended size to allow for cutting and shaping. Once I have decided on what bolster material to use I get the sides flat and parallel on my granite surface plate. Sometimes I'll use my mill to get parallel surfaces.


IMG_6014 by Robert Erickson, on Flickr


I'll use marker or pencil to draw the outline of the knife on each piece to help me keep them straight. (I invariably drop one on the floor and reverse them and that's aggravating, especially if I'm using bookmatched wood with a nice grain pattern!)

fullsizeoutput_40a by Robert Erickson, on Flickr

Then I clamp and drill.

IMG_6017 by Robert Erickson, on Flickr

Holding pins are used to keep the two halves together for shaping and rough cut to length.

IMG_6019 by Robert Erickson, on Flickr

The back side that mates with the handle material needs to be perfectly perpendicular and flat. Some guys use a disc sander for this, I use my flat platen. I use 1 2 3 blocks to square it and then sand the backs flat and square. (NOTE: This only works if the sides of the material are parallel)

IMG_6020 by Robert Erickson, on Flickr

I'll then touch up each individual piece by manually pulling the sanding belt. Note the fresh 120 grit belt :-) You don't want to remove much material here otherwise the pieces won't match. (In this picture I'm not holding the bolster, normally I would be, but I don't have 3 hands LOL)

IMG_6022 by Robert Erickson, on Flickr

Check for square and flat surfaces with a strong back light:

IMG_6023 by Robert Erickson, on Flickr

IMG_6024 by Robert Erickson, on Flickr

To be continued... Hope this is going to be helpful.
 
I lay the knife with the newly minted bolster over the handle material, decide where to position it and trace it with a marker. I try and dummy proof the process as much as possible.

IMG_6025 by Robert Erickson, on Flickr
fullsizeoutput_40b by Robert Erickson, on Flickr

The inside surface is flattened with 80 grit Rhynowet paper on the granite plate. I then go to the flat platen to flatten and square the surface that mates with the bolsters.

IMG_6027 by Robert Erickson, on Flickr

I check for square with a machinists square and or a 1 2 3 block.

IMG_6028 by Robert Erickson, on Flickr

I usually use liners. I like the look and they end up becoming the vehicle for the handle and bolster. This particular knife is getting dual liners and a spacer between handle and bolster. (When using a spacer make sure to flatten the edge that rests on the liner or there'll be gaps)

IMG_6035 by Robert Erickson, on Flickr

All the surfaces get roughed up with 80 grit paper and cleaned thoroughly with denatured alcohol.

fullsizeoutput_40c by Robert Erickson, on Flickr

IMG_6032 by Robert Erickson, on Flickr

It's important to work efficiently here because even though medium fast CA glue is used here it's still pretty fast. Have everything laid out and ready to go. I press and hold for 5-10 seconds as I glue each piece together. Then clamp everything to a piece of angle iron (with wax paper in between) using spring clamps.

IMG_6033 by Robert Erickson, on Flickr

IMG_6034 by Robert Erickson, on Flickr

Full cure for most CA glue is 12-24 hours so I usually wait over night to start working with it. It's probably safe to proceed sooner but I don't like starting over at this point.
 
I next cut off the excess liner material at the band saw.

IMG_6036 by Robert Erickson, on Flickr

Quite often the bolster and handle material aren't the same thickness so I get them even and flat at this point. (It also lets me check for gaps between the materials. If I have any, it's time to be bummed because it's time to start over.)

fullsizeoutput_40d by Robert Erickson, on Flickr

IMG_6038 by Robert Erickson, on Flickr

IMG_6040 by Robert Erickson, on Flickr

Then it's back to the surface plate to get the liner perfectly flat

fullsizeoutput_40e by Robert Erickson, on Flickr

fullsizeoutput_410 by Robert Erickson, on Flickr

Then I need to drill out the front pin holes in the liners.

IMG_6044 by Robert Erickson, on Flickr
 
I then check for alignment with holding pins through the two holes in the bolster. I usually put the blade in between the two halves and reverse them as is pictured. I do this so I can mark the top of the handle material so when I go to drill the remaining pin holes I keep the alignment correct. The holes in the tang are sometimes too big for the pins and this creates "play" so marking the blade position helps avoid misalignment when drilling.

IMG_6045 by Robert Erickson, on Flickr

IMG_6046 by Robert Erickson, on Flickr

IMG_6047 by Robert Erickson, on Flickr

Then I cut and sand off the excess handle and bolster material getting them sized to the tang. This leaves less work (and heat build up) after glue up.

IMG_6048 by Robert Erickson, on Flickr

IMG_6049 by Robert Erickson, on Flickr

IMG_6050 by Robert Erickson, on Flickr

Now it's time to address the front of the bolsters. The two halves are pinned and shaped as you would normally do the front of your scales.

fullsizeoutput_411 by Robert Erickson, on Flickr

IMG_6052 by Robert Erickson, on Flickr

IMG_6053 by Robert Erickson, on Flickr

Hand sanding finishes them to final grit. Depending on material I'll go up to 1200 grit.

IMG_6054 by Robert Erickson, on Flickr

IMG_6055 by Robert Erickson, on Flickr

I like to dimple the liner to create little "epoxy rivets" and then take a few passes on 80 grit paper to remove the drilling swarf.

IMG_6056 by Robert Erickson, on Flickr

fullsizeoutput_412 by Robert Erickson, on Flickr

I use my 2" small wheel and an old 36 grit belt to create a concavity in the tang as an epoxy reservoir and for weight reduction.

IMG_6058 by Robert Erickson, on Flickr

IMG_6059 by Robert Erickson, on Flickr

I rough up the rest of the tang with 80 grit paper then use denatured alcohol to clean all the surfaces.

IMG_6060 by Robert Erickson, on Flickr

IMG_6061 by Robert Erickson, on Flickr

IMG_6062 by Robert Erickson, on Flickr

I use West System G-Flex epoxy to glue the scales on and clamp with some spring clamps. I will wait an hour or so and then clean up the squeeze out. I'm especially attentive to the epoxy on the front of the scales which I remove with a Q-tip slightly moistened with denatured alcohol.

IMG_6063 by Robert Erickson, on Flickr

There you have it

I'll wait a good 12 to 24 hours before shaping the handle.....
Some of the process may be a little unconventional but it seems to work for me. Hopefully it will help someone out there that's been thinking of doing bolsters but hasn't taken the plunge.
 
Beautiful work and great instruction. This is something I haven't attempted yet and now plan to after reading through this. Thank you!
 
That's awesome, and validating, as it's pretty much what I do. Question: what is the wood on those scales? Looks like Mango. I have a bunch of it, and I like they way it looks on your knife. Thanks.
 
Many thanks for the instructions! It's always educational to see how others do it. It's easy to get narrow sighted.
 
Thanks for sharing!
It always amazes me how many different approaches can be used for the same basic job
 
Thanks guys!

Kevin McGovern said:
That's awesome, and validating, as it's pretty much what I do. Question: what is the wood on those scales? Looks like Mango. I have a bunch of it, and I like they way it looks on your knife. Thanks.
Click to expand...
That is Curly Mango from Mark at Burl Source. Lots of movement and depth to it.
 
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