Looking for sharpening advice

T

TheEdge01

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Apr 3, 2015
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I’m not new to sharpening knives, but I just can’t get that acceptable edge on my new Sog Pentarc that I like. I have been using the Sharpmaker for close to two years and have sharpened numerous blade steels such as S30V, 154cm, VG10, Niolox, D2, 14c28n, plus a number of softer steels. I use the scissor sharpening slot on the back because I rarely found knives that had 15 and 20 degree angles on both sides.
I don’t know why I am having so much trouble with the Pentarc. I love the knife, and I would like to get a nice keen edge on it. I sharpened up a new Griptilian with 154cm blade steel yesterday in about 3 minutes. Does Sog put weird angles on their blades?
 
hold on: you're using the scissors slot for knives? with the scissors angle that's like really shallow?
 
SV-97 said:
hold on: you're using the scissors slot for knives? with the scissors angle that's like really shallow?
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Ok, yes I use the scissor slot, it does have a slight angle to it but I find it easier to turn the knife and find the correct angle. I’m not sure how that is shallow since I don’t hold the knife directly parallel to the sharpening rods plus I sharpened numerous knives this way.
 
TheEdge01 said:
Ok, yes I use the scissor slot, it does have a slight angle to it but I find it easier to turn the knife and find the correct angle. I’m not sure how that is shallow since I don’t hold the knife directly parallel to the sharpening rods plus I sharpened numerous knives this way.
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Ohhh ok, gotcha. I thought you used the angle on the scissors "setting".

Well I can't really help you as I never had a SOG knife but being VG-10 it should sharpen up nicely. Have you tried the sharpie trick? Or looking at the edge with some magnification to inspect the scratch pattern?
 
SV-97 said:
Ohhh ok, gotcha. I thought you used the angle on the scissors "setting".

Well I can't really help you as I never had a SOG knife but being VG-10 it should sharpen up nicely. Have you tried the sharpie trick? Or looking at the edge with some magnification to inspect the scratch pattern?
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I haven’t done the sharpie trick yet, I’ll try that next. This thing just has me puzzled because it should sharpen up just as easy as 154cm.
 
Might be worth inking the edge bevels with a Sharpie, and then see where the ink comes off as you're sharpening it. Odds are, the edge angle is wider than you're used to, and the contact on the rods is up on the shoulders of the bevels, without contacting the edge itself.

The blade profile on that knife, a dirk/dagger type of primary grind, is usually wider in cross section (angle-wise), than other blades made for fine cutting/slicing. If that's the case on your knife, the secondary grind angle at the edge will be even wider. It's pretty typical on grinds like that.
 
Obsessed with Edges said:
Might be worth inking the edge bevels with a Sharpie, and then see where the ink comes off as you're sharpening it. Odds are, the edge angle is wider than you're used to, and the contact on the rods is up on the shoulders of the bevels, without contacting the edge itself.

The blade profile on that knife, a dirk/dagger type of primary grind, is usually wider in cross section (angle-wise), than other blades made for fine cutting/slicing. If that's the case on your knife, the secondary grind angle at the edge will be even wider. It's pretty typical on grinds like that.
Click to expand...

I will give the sharpie trick a shot. What you are saying makes sense, it probably is a much wider angle.
 
Some people report that VG-10 steel forms really tenacious burrs that are hard to remove. They flop back and forth over and over and won't break off. Ceramic sharpeners like the SharpMaker are known for producing burrs also. That combination might be producing a big burr that's hard to get rid of.

I would cut the edge off. Meaning, cut directly into the sharpmaker rod like you were trying to cut it in half. But do it LIGHTLY. Very lightly. No more than about 4 strokes. That will flatten the cutting edge and cut off any burr that might be there.

From there you will have to re-establish the cutting edge again, but it shouldn't take too long, as long as you only cut the edge off *lightly*. As a bonus, this flattened edge will reflect light if you hold it correctly so you can see it. This provides you a good visual indication of your progress in sharpening. The reflection will get more and more narrow as you form a new cutting edge. When the reflection is totally gone, you probably need something like 30 seconds of work on each side. I would go back and forth at this point and not concentrate on one side more than the other. Individual strokes back and forth, for about a minute.

Check it using your sharpness tests. Continue going back and forth if you need to. Hopefully this will help minimize any burr formation and let you form a sharp edge.

Good luck!

Brian.
 
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