Could you post a tutorial on how you sharpen? I
use waterstones but hate the hassle of trying to keep
them flat. I have my grandfather’s oil stones some
maybe 50 or 75 years old (just guessing) I …would love
to see your thoughts in pictures.
Glad to help. I don’t use waterstones, but I did
spend years using composite stones that also hollowed
badly. There are a couple basic techniques you can
use to minimize the hollowing. The first is to use
the entire surface of both sides of the stone wherever
you can…. not just the center… and the other is to do
more on the grinder and less on the stone when
completely redoing a bevel.
Using the entire stone sometimes means you have to
forego some jigs, but it’s always good to develop your
ability to sharpen freehand as I can think of dozens of
situations in even hobby woodworking where your bench
and jig won’t be available. All the grandiose
words written in the last couple decades on honing, all
the expensive gizmos for sale to help you do it, and all
the trouble folks seem to have with it puzzle me some.
Grind that blade correctly, and the difference in
cutting speeds and technique between oil, water or
composite stones is meaningless because there isn’t
enough honing to be done to measure a difference.
So I’ll go you one better on your question. I’ll
convert an old abused, 2-dollar half-inch firmer chisel
to a small skew for lathe work. Lotsa grinding
required here…and on burnable 19th-Century carbon, not
burn proof High Speed Steel. Get good enough
freehanding on your stones, and it takes no longer to
put your best edge on that carbon skew using stones as
it does to put an inferior edge on an HSS skew using a
grinder. I mark the bevel I want on the chisel
using a bevel gage and carbide scriber…
…and grind off the old edge square to the line.
Looking at the squared-up flat I made, the chisel’s old
bevel largely remains on the bottom side in the pic, but
the flat penetrates to at least the center of the bevel
at the point of the skew to leave enough steel there to
grind a perfect bevel and edge next. The objective
in all sharpening is razor-sharp… but also consuming
minimum steel in the process.
I’m using the coarsest grinding material I have… both my
coarsest grinding stone and 26-grit sanding disks for
the roughing work. The coarser the abrasive, the
cooler it cuts and the faster you can do the job without
stopping to cool the steel with every stroke.
Remember that if you turn that steel blue with the 600
degrees it takes to do it, you’ve ruined its temper and
all that blue must be ground off for that steel to hold
an edge. Takes two minutes to grind.
Next I grind the 20-degree bevel on both sides of the
skew. I use the tool rest and the side of the coarse
wheel in the 8”, 1750-rpm buffer-grinder. No jigs, no Tormeks, just that angle gage sitting handy on the
grinder stand to show me what 20 degrees looks like when
grinding either side… working all that out with the
wheel stopped, of course.
Takes 5 minutes, taking a
little bit off at a time then dipping the tool in water
and examining the cut for any adjustments in my hold
required. The closer I get to forming an edge, the
easier it is to burn the edge.