How to Make Better Bolsters

How to Make Better Bolsters

I also run a bead of Crazy Glue along the edges of the assembly to help secure everything in place and keep parts from moving and shifting as I start the initial work. It is important not to overstress or overheat the stacked layers during this critical stage of construction. Be careful not to melt the glue and tape. Until we get screws in place, it is important that the layers stay aligned.

After making sure the band saw and worktable are square, I carefully cut the bolster to rough shape, just outside of the design line. I try to cut as close as I can to the line, but still leave myself a little room for cleanup. The band saw makes some rather rough marks along the newly cut edges.

You want to give yourself enough room to grind out those marks without grinding into your profile. If you cut too close to the line, by the time you’re done finish-grinding the saw marks, the bolster could be undersize. The band saw does not cut curves. You can tweak the blade a bit, but you’ll have to take off large chunks of material at a time from in the curvy areas. Yes, lots of material and money end up on the floor!

On the grinder, using the back platen with table accessory, clean up the convex areas of the material stack only. Before doing this, you should knock off any rough burs created by the band saw on the bottom side of the material stack, using either a fine file or by running the stack across 320-grit sandpaper on a flat surface. The material stack should rest flat on the table, thus assuring square grinding.

There are two areas along the profile to stay away from for the moment, still leaving them rough, and therefore a bit oversized. These are the areas—shown with arrows in the accompanying photo—that share the outside profile with the rest of the knife. Blend those later after you know proper placement of the bolsters on the knife.

Now it’s time to clean up the concave areas with an oscillating spindle sander. This is traditionally a woodworking tool, but it works great for knifemaking and keeps all parts at precise 90-degree angles in relation to each other. I recommend finding an oscillating spindle sander with a laminate top, as opposed to a metal top. The laminate top will cause fewer scratches on your material as you’re moving it around and into the sanding drum.

The Aggressive Grit

You can also get several different grits of sanding sleeves. Start with the most aggressive grit sleeve to quickly erase the band-saw-blade marks. Again, this is a woodworking machine, so it does not have a lot of natural aggression. Compensate for this by using the most aggressive grit sleeves. As you get closer to a finished profile, change incrementally to the smoother grit sanding sleeves.

In the accompanying photo, you can see the difference between the now-smooth areas that were finished up using the sanding machine, and the still-rough, band-saw-cut areas. The small, hooked area of the bolster, as well as the tip in front, will be cleaned up later with a different tool ideal for tighter areas.

Apply Dykem steel bluing layout fluid to the general area on the frame of the knife where the bolsters will meet it.

Using the calipers, measure and lightly mark where (according to your full drawing of the bolster area of your own knife) you want the rear, bottom edge of the bolster to rest against the handle.

In the related photo, it’s easy to see, in the slight, rough overhang of the bottom-rear-most concave area of the bolsters (now lying in place on the knife), why I suggested leaving that part unfinished after the band saw cut. It is the area that will be blended once the bolster is secured in place.

Use a small, preferably copper-jawed, clamp to hold the bolster stack to the knife body. Copper-jawed clamps lock up precisely and don’t mar surfaces, as do steel C-clamps. Get in the practice of wiping off the contact faces of the clamp, even if just with your fingers. This will prevent any dust or grit from getting on your work, potentially scratching surfaces or preventing proper lock-up of the clamps to your work.

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