Installing new bolsters

[Jeffinn]

The topic of bolster installation came up recently and I was asked to share my technique for getting bolsters installed so that the lower bolster is squared or parallel to upper bolster. My technique is derived from a few different YouTube videos. There’s probably other ways to do this but this is how a I do it.
To make it easier, I cut three different rectangles out of 1/8” aluminum bar stoc picked up from the local a Home Depot. I cut three different lengths, 2.5”, 2.75” and 3”. These should be adequate for most of the knives that I work with.
I’m working with an electricians knife so I decided to use the 2.75” spacer block. I set block on the liner and press it up against the upper bolster then clamp or hold it in place and scribe a line,

Once the line is scribed I remove the spacer and use a lead pencil to fill in the area outside the line,

The pencil lead (or graphite if you prefer) will keep the solder from flowing into areas where it’s not wanted.
Next I flow some solder onto the knife liner where the new bolster will go. Sand the area first, apply some flux and solder and heat the liner until the solder flows. You can use a small piece of wire or rod to move the molten solder over the entire surface. Try to knock off any excess solder while it’s still hot. Do the same thing with the new bolster piece.

Let everything cool a bit, then clamp the spacer block back onto the liner. Place the bolster piece into place tightly against the spacer and clamp in place. Now heat the bolster until the solder flows and let cool.

Remove the spacer block and clamps.
A quick trip to the belt grinder to remove the excess bolster material and we’ve got a couple of new bolsters roughed in and ready to go.

Hope this helps.
Jeff

[btrwtr]

Great explanation. Looks like you have it down.

[Meridian_Mike]

Very nice instructional thread Jeff!
I had no idea that graphite would stop soldier....
I did use the "tinning" idea on my last bolster install. Thanks for showing that also!

This is just a really nice all around instructional thread with some great pictures!
Thanks Jeff!

[tinkerer]

Thanks for posting this! What solder/flux are you using if you don't mind my asking?

[Jeffinn]

I originally used the Stay-Brite silver solder Kit. It has the solder and liquid flux.
Recently I went to the local Home Depot and purchased some silver solder with the same tin and silver content from the Bernzomatic torch section. And some paste flux.
For bolsters, the low temp solder works just fine. And the Home Depot variety works just as well as the Stay-Brite Kit.
However, If you’re only soldering an occasional bolster, the Stay-Brite Kit is perfect.

[tinkerer]

Thanks!

[Reverand]

I would not have thought of that technique, but it makes perfect sense when you explain it. Solder should't stick to aluminum, and your 'tinning'' the parts first keeps excess solder from leaking out anyway.
Thank you so much for sharing!

[Ozwelder]

Thank You Jeffin,
It is a top tip.
Ozwelder