There are several good uses for a belt sander
even if you do not it to sharpen knives: This description is for a
Viel Tools S5 sander/grinder but can be adapted to any belt sander.
1. Reduce the bolster of a chef’s knife that has been sharpened in a pull
through sharpener and developed a swale or low spot.
Lay the sander down so the belt is horizontal and moving away from
you. Hold the blade across the belt just as if you were sharpening,
but only grind the bolster. You can improve the appearance by
rocking the blade from about 20 to about 50 degrees, and by using the
short slack belt section between the platen and the idler wheel.
Grind until the bolster is no longer higher than the edge. I also tilt the
handle down so the bolster is lower nearer the handle. If the sander
finish is not okay it can be corrected with a coarser or finer Rust
2. Reshape a chopping knife with a swale or low spot so it racks against
the cutting board. (Santoku, unbolstered chef’s knife or bolstered
chefs knife after the above operation) See Knife Defects page
Lay sander horizontal as above. Hold the blade parallel to the belt,
spine up, edge down. Rock the cutting edge on a belt until the swale
is gone. This requires a platen as long as the blade. Of course you
dull the edge in the process, but you CANNOT create negative curvature
against a flat platen. If you hold the blade about 45 deg. to either side
for the last two passes you start the re-sharpening process.
3. Grind a strong convex edge on a chopping tool. (Axe or camp
Lay sander horizontal as above, edge across the belt. Sharpen the edge on
the short slack section between the platen and the idler wheel. Angle will
control how far up the side of the blade you sharpen. Position closer to
the platen for stronger edges (axes) and a little further back for a
sharper edge (knives)
4. Garden tools that do not open 90 degrees (anvil pruners and grass
Set the sander up so the long slack section opposite the platen is up and
turning away from you. Bring the belt between the blades (or blade
and anvil) at the sharpening angle. Try it first with the sander off
to see how it fits and if you can move it the full length of the blade.
This is a safe operation if the blade and the anvil form a V with a flat
bottom (pruner) and dangerous if the blades form a V with a sharp bottom
(grass shears). The sharp V will pinch the belt, shred it ($5 gone)
and possibly throw the tool. If anyone asks, I do not recommend
this. Do as I say and not as I do. Be careful and WEAR YOUR