Help with the Sharpmaker ...

V

Veri

Joined
Oct 15, 2004
Messages
6
Hey all, (somewhat) new to the forums here. I've been lurking around here (and the Spydie forums) for some time, though; high-end knives are something of a discovered interest to me. To start the collection, I received a Centrofante III and a black-blade FRN Delica yesterday. ;) As a result, I've used one of NGK's included band-aids and have a couple of inches of arm shaved clean.

Also ordered the Sharpmaker for maintenance, as well as sharpening those knives I already have laying around. I'm pretty much a novice, though, so that would explain this little problem I'm having. I pulled an old, generic hollow-grind kitchen knife to get me started, and just trying the 204 out, I was unable to really do anything. So, I tried the marker trick, and sure enough, the bevel was coming clean but a really thin line of black was left on the edge. Now, I don't know if this is an angle problem, my positioning mistake (tilt the blade a bit into the stones), or what, but that's what's going on.

Just looking for the voices of experience. :D
 
The marker line is at the edge or the shoulder?

If it's at the edge, you need to keep going. If it's at the shoulder that I'm not really sure what you're doing wrong. :confused:

What angle are you using?
 
Shoulder ... the actual edge edge, where the knife touches what you're cutting, still has a very thin black line. (I think I've the terminology right...?)

I've tried both 30 / 40 with the same general thing happening. Not totally sure what's going on.
 
If there is a black line at the edge you have to remove more metal. You don't change the angle, just keep making passes. Did you watch the video?
 
Patience pays. Use slow full strokes and keep the knife straight. If you are using a really cheap kitchen knife don't expect to turn it into a razor blade.
 
If your black line is along the edge you simply have more work to do. This is very common with a well used kitchen knife. If it is hollow ground you might as well do the work with the 30-degree setting and get a really sharp edge. That will take more time than the 40-degree setting, but you'll be impressed by the results.

Do most of your work using the edges of the darker (medium grit) rods. This is the most efficient way. Keep doing right-left-right-left strokes on the medium rods until the entire edge feels sharp and all of the black ink is gone. You may want to twist the rods in their sockets every 50 strokes or so to even out wear and to work on a fresh rod edge. Be sure to only use a moderate amount of pressure as you work on the edges of the rods or the force concentrated along this narrow rod surface will fatigue the metal at the edge. You may need to spend 10 minutes up to 30 minutes doing this with a really dull knife (luckily you have a hollow ground knife because you might spend an hour doing this with a saber ground edge). The ceramic rods don't cut all that fast.

Now switch to the flats of the medium rods. You probably only need to do about 10 pairs of right-then-left strokes to smooth out the somewhat rough surface left by all that work done with the rod edges. The additional trouble is that you removed a lot of material with all that rough sharpening and consequently you have a residue of loose material at the edge (a "burr") that you will need to remove. Switch the rods to the 40-degree setting. To deburr you need to tilt the spine of the blade towards the center (away from the rods) as you do about 5 left-right stroke pairs using light pressure. What I do to be consistant is lay the blade flat on the right-hand rod to set the angle that I want to use and then move the blade over to the top of the left hand rod and stroke down the rod while holding that angle. Then I tip the blade over so that it is flat against the left-hand rod to set the angle I will use when I stroke down the right hand rod. Don't worry about being precise. The exact angles are not important. You are basically doing a few very light strokes at an 80-degree included angle (40 degrees per side) so that you can cut off the floppy burr material at the edge.

Once you have deburred the edge put the rods back into the 30-degree slots rotated so that you are working on the flats of the dark rods. You want to get rid of that 80-degree micro bevel you just put on. Do about 15 pairs of left-right strokes at this angle using light pressure. Now switch to the flats of the white rods and do about 10 pairs of left-right strokes using light pressure. To finish off, move the white rods to the 40-degree slots and do about 5 to 10 pairs of left-right side strokes on the rod flats using only feathery light strokes. This should leave you with an extremely sharp shaving edge along the entire blade length.

You only need to go to this extreme of sharpening once as long as you periodically maintain the edge using the sharpmaker. The instructions in the Sharpmaker video are more typical of what you do with a new blade or a blade that you have previously restored using the method I explained above. After a month of typical kitchen use (assuming that you always work on a soft wooden or plastic cutting board--which is an absolute must have in your kitchen) you should only need to do about 5 light pressure stroke-pairs on the medium grit flats at 30-degrees and about 5 light pressure stroke-pairs on the white rods at the same angle and then finally do about 5 extra-light pressure stroke-pairs on the flats of the white rods with the 20-degree setting.

When I work on other people's kitchen knives that haven't been sharpened in 20 years (they are commonly knives that they received as wedding presents and now their oldest child is in college) I wouldn't dream of starting out with a Sharpmaker. I usually leave them with a couple loaner knives and take theirs home to work on my belt sander. It can take me 15 or 20 minutes to restore one of these knive even when I do 85% of the work with the sander. I may need to start with an 80 or 100 grit belt. I usually work my way up to a 320 or 600 grit belt before I switch to a manual 1000 grit water stone. I finish with the Sharpmaker, but I only do a deburring and maintenance level sharpening effort on the rods. The big work is done on the power tools. I even do some of the deburring on a 320 or 600 grit belt.
 
Dont be afraid to take the book to reading room with you , then watch the video again. Ive seen mine 3 times, even the kids watched it with me once.
 
Veri said:
Shoulder ... the actual edge edge, where the knife touches what you're cutting, still has a very thin black line. (I think I've the terminology right...?)

I've tried both 30 / 40 with the same general thing happening. Not totally sure what's going on.
Click to expand...

Patience, you just need to keep at it until you get the bevel you want. If the knife is dull or at an angle much more obtuse than want you want (30 or 40), there is a _lot_ of material on that shoulder to remove.

The good news is you only have to do this once (should be good for a year or much longer).

For kitchen knives, I like to do 30 until I get the entire bevel re-profiled and then switch to 40 to create an edge bevel..

If you are impatient a flat diamond stone can be used to speed up the process freehand.
 
It really good addition to the sharpmaker would be a coarse benchstone (DMT 220 or 320 would work well and can be had for $30 if you shop around on the internet). You can lean it against the SM rods (mmmmh that didn't come out right :D). Or you can make a wooden wedge of 15 deg against which you can lean your knife to get a feeling for the right angle and against which you can check whether you hold the angle or not. Essentially you are trying to remove the backbevel which is a lot of work on a really blunt knife. But once you have accomplished that, touch up on the sharpmaker requires only a few strokes and you will see results immediately. Also, by maintaining your knives with the sharpmaker, you will never have to go back to the benchstone again.
 
guy g said:
Dont be afraid to take the book to reading room with you , then watch the video again. Ive seen mine 3 times, even the kids watched it with me once.
Click to expand...


You're sick! :p

Your kids are going to be knuts. :D
 
Just an added point...

When using a Sharpmaker, or any crock-stick type sharpener, you will round off the tip if you pull the full length of the blade until it slips off the stick. I adjust my stroke so the blade contacts the base of the Sharpmaker, leaving about 1/4 inch unsharpened at the tip (actually I don't usually make contact with the base on most strokes but if I pull a little too far I'll hit the base rather than pull the tip across the stick). I then sharpen the tip separately, if it really needs it - PUSHING the blade into the stick lightly rather than pulling it. I don't use the tips heavily anyway so they don't usually need sharpening - usually the stropping keeps them sharp enough for me.
 
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