two different sharpening methods

H

howardaw

Joined
Oct 20, 2003
Messages
9
Hello,

I'm trying to learn to sharpen blades, so far I have a lansky and a sharpmaker. I have decent success with both (on an endura). I now have a cqc7 and a crkt m16 that I want to sharpen. The emerson is a chisel grind, the m16 looks like it is a chisel, but the factory says otherwise. My question is that both the crkt folks and the emerson page (where there are photos of him sharpening a commander with some type of diamond rod) advise to sharpen by pulling the blade back across the stone/rod vs "cutting" into the stone. The both then recommend stropping (sp?)...a legal pad cardboard seeming to get a lot of recommendations. What are the pros and cons to pulling vs cutting into the stone or does it matter at all? Also, the lansky has a 30 degree setting (for the cqc7...though I understand it is slightly different than the factory 30 degrees)...what would be the best way to sharpen the cqc7 with the sharpmaker? Thanks in advance...

Howard
 
howard :

What are the pros and cons to pulling vs cutting into the stone or does it matter at all?
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Pulling is a less aggressive action and is mainly for alignment of a just slightly less than optimal edge, it however tends to produce burrs readily.

what would be the best way to sharpen the cqc7 with the sharpmaker?
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In general, few knives will match the preset angles on the Sharpmaker, you thus have two choices :

1) grind away on the Sharpmaker until the angles match

2) sharpen freehand using the stones

In both cases mark along the edge with a marker so you can tell where metal is being abraded.

-Cliff
 
Well, I've managed to totally remove my edge from the cqc7 (it would partly shave before...wasn't very sharp from the factory, IMHO...now, it's an expensive butter knife). So, I guess I need to regrind an edge anyway. I would have guessed the chisel to be easier, but perhaps not.

howard
 
Most recommendations on sharpening chisel grinds are to completely sharpen the front or beveled side and then just strop the back, this produces huge burrs which are difficult to remove. Chisel ground knives would be much better off if they were sharpened the same as chisels. You lapp the back to a high polish and then hone the edge. You then lapp the back again and you should be done. You might need to alternate between the edge bevel and the back a couple of times to fully remove the burr and get a crisp edge same as you would with an ordinarly v-bevel. Essentially there is no difference between a chisel edge and a v-edge, except on a chisel edge the two intersecting angles are not the same. There is no reason to treat it any differently when sharpening once this is taken into account.

-Cliff
 
Interesting, I'll give that a whirl. I was able to raise a burr for the first time (and feel it) with a course diamond hone from a lansky set (though I wasn't using the lansky setup, the 30 degree angle is very different and I'm not ready to do a complete regrind yet). However I managed to screw it up at some point and it is dull now. So the front side is around 30 degrees and the backside is very steep, like 5 degrees or some such??

Thanks...

howard
 
Yes, the back is usually flat. lay the knife on the sharpening stone and just grind flat to the stone.

-Cliff
 
So, how exact does the angle in stropping (stroping?) have to be? Very, the same as sharpening or not as precise...and can stropping alone screw up an already pretty sharp blade?

howard
 
I just found it very easy to screw up a knife stropping it.

All you have to do is strop at a higher angle than the edge bevel, or "curve" up your wrist as the knife reaches the end of the strop stroke.

Then you put a nice, round edge over the sharp one.

Voila, instant super dull knife....

*sigh*

-j
 
Here's how I sharpen chisel ground emersons on the 304 sharpmaker:

Sharpen the beveled edge, then one pass on the ceramics on the other side [ very lightly ].

Seems to work without much effort.

Brownie
 
howardaw :

So, how exact does the angle in stropping (stroping?) have to be? Very, the same as sharpening or not as precise...and can stropping alone screw up an already pretty sharp blade?
Click to expand...

Stropping is usually done on a soft medium and thus the angle tolerance is very low as the media will conform to the angle. If you strop on a wooden block then you need to match the angle precisely.

Stropping can damage sharpness, this is usually done by not raising the knife on the end of the stroke but instead flipping it over which will readily round the edge. You can also press really hard on the strop which will very light induce burr formation.

Stropping as a finishing step should be very light and limited to a few passes, if you are doing more then the required work was not done on the hones.

-Cliff
 
I use the back (rough) side of an old leather belt that's about 2" wide. I don't put anything on it, it's just bare leather. I put just a little pressure on the blade and keep the pressure evenly applied along the blade length and try to match my sharpened angle. Maybe just a hint more angle (if any). I then slowly, deliberately, move the knife in the direction of the spine of the knife for about 6"-8" down the leather. I do not curl or flip it over to do the other side. I lift it straight up off the leather. I only do one or two strokes to get the entire length of the blade, then flip it over and repeat. It does a nice job of finishing the edge up.

I have also had decent results with simple cardboard. The reason I use the old belt is because I had it on hand.

To be completely honest, I could live without stropping. My knives get sharp enough simply using the hones.


Mike
 
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