Knife Sharpening on a Tormek
by Curtis Womack
posted 2/8/2005 on the TormekUsers group at Yahoo Groups
https://groups.yahoo.com/group/tormekusers/message/995
Unlike a lot of people who purchase a Tormek to sharpen woodworking
and other tools, I purchased mine to primarily sharpen knives. I
spent a lot of time working on this, and have gotten to the point, with
a lot of trial and error, where I have been able to put a decent edge on
a knife, and after the recent posts on grading and honing, have improved
that edge. I think the Tormek is great at knife sharpening, and so
I thought I would share how I sharpen a knife. (I wrote this as a
'beginner's guide' so don't be offended.....) Also note, I don't
receive anything for products I mention... they are just what helped me.
I am assuming a jig will be used.... freehand is a little different, and
relies more on technique and skill level.
Some preliminary stuff
The basic principles of sharpening a knife apply to the Tormek. To
learn more, take a look at
https://sharpeningmadeeasy.com
There
is
a
lot of information on the site and if you're new to sharpening consider
purchasing his book "Sharpening Made Easy". You might also
consider "The Razor Edge Book of Sharpening" found at https://www.razoredgesystems.com
Both
cover
the
same principles... "Sharpening Made Easy" to me is a better read.
Some of the key principles that apply to sharpening on the Tormek are:
Establish / Re-establish a good bevel on your knife.
Sharpen until you obtain a burr.
Hone and refine the edge.
Machine setup
From what I recently learned in the other posts, use the stone grader on
the stone to establish a flat smooth surface. I wasn't using the
stone grader long enough... basically I doubled the time what the book
recommended, used a fair amount of pressure, and it made a big
difference in the results. Don't sharpen at the coarse grit,
unless you have a severely damaged knife.
Charge the leather wheel with the Tormek compound or its
equivalent. I tried using the green Chromium Oxide... but I think
that this is too fine coming from the stone. The Tormek compound
worked much better for me.
Place the knife in the jig, according to the instruction book. A
couple of things I do here:
I measure the distance straight out from the pivot point (where the jig
will meet the universal support) to the edge of the knife, and then
position the knife so the distance from the pivot point to the tip of
the knife is the same. This insures a nice even bevel.
I set the adustable stop on the jig at 0.... cause I'm gonna use it
later to establish a secondary bevel.
Set the knife angle using the Anglemaster to the desired sharpening
angle. (See manual). The magic marker trick works well if
sharpening a knife that has a good existing blade geometry, but most
don't. Also make sure that the jig isn't hitting the stone.
One tip I recently learned here is to make sure the corner of the bottom
of the angle guide on the anglemaster is touching the stone. You
get more consistent results.
Sharpening
Sharpening is done pretty much how the manual states. Sharpen one
side until a burr is established, flip it over and do the other
side. A few things that helped me:
Watch the water flowing over the edge. This tip in the book is a
very good one. It doesn't take much pressure on the handle to rock
the knife on the stone, so make sure it stays flat.
It does not take a lot of pressure on the knife. This is a
subjective statement, but the biggest tip I can think of here, is, if
you're not sure, err toward the side of lighter. I think the
Tormek is a little deceptive in how much metal you're removing, but
remember, you're moving an approx. 1000 grit stone over your knife at
around 2 ft. per second. You're moving some metal. (Tape a
magnet to the outside bottom of the water dish if you want to see it).
Make sure the burr is established along the entire blade. Trouble
spots are the tip, where a blade curves, and the heel of the blade.
Once both sides are done, if you want to create a secondary bevel, use
the adjustable stop on the jig. 4 turns approximately = 5
deg. Turn it in.... raising the knife on the stone. 2-4
turns works well, depending on your preference. (If you want to
check to be sure you're going the right way, use the Anglemaster... you
should be getting a higher angle reading). Sharpening the
secondary bevel does not take much at all... usually only a pass or two
on either side... and lighter pressure.
Now, one of the biggest tips that helped me, (and it's in the manual) is
grind the burr off with very light pressure. I do this by barely,
barely touching the knife to the stone. Did I mention
barely? My goal is to try and completely remove the burr prior to
honing. This was the biggest mistake I made when learning, is I
would try to remove the burr on the leather wheel, and I could not get a
sharp knife. I cannot emphasize this enough.... if you don't have
a decent cutting edge prior to honing.... you're not done on the stone
yet. Maybe everybody gets this but me... but for me, this was my
greatest find.
Honing
Once a good cutting edge is established on the stone, remove the knife
from the jig (or you can reset the universal support if desired) and
hone the knife. Honing could be optional here, but I recommend at
least one or two passes, cause a slight burr will probably still
remain. (You can tell if you have a burr, cause it will throw
debris on the top side of the blade during honing). A couple of
tips here:
Don't hone to steep. Try to match the sharpening angle. To
find a good position try this..... with the wheel OFF, lay the blade on
the leather wheel near the top, and rock it back and forth (so the edge
moves toward/away from the leather). Find the point where the edge
just contacts the leather. A good light helps here, or you can
slightly push the edge forward... it should just catch the
leather. Now turn the wheel on, and hone at this angle.
Remember to hone so the wheel is moving away from the edge.
1-2 passes should remove any burr... further honing refines the
edge. I found I could "overhone" a blade for its intended use...
creating a sharper edge, but it would lose some of its bite.
A few final thoughts.....
One thing that really has helped me in learning to sharpen, is I bought
one of those handheld microscopes from Radio Shack. (About $10.00)
It really helps me to see the edge when I'm sharpening, especially at
"trouble areas" like the tip. Sometimes I'm surprised... I'll do
everything the same, but get different results, and can't figure out why
until I look under the microscope.
Like I said, I'm new to this, and am still learning. I just
thought I would share what I've learned so far. Feel free to add
or critique this, so I can improve on my sharpening skills.
Hope this helps!
Curtis Womack
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