Problem getting my knife sharp with sharpmaker

T

toad224

Joined
Jul 5, 2006
Messages
31
I just got a sharpmaker, and I was testing it out on a cheap kitchen knife. I followed the directions to sharpen it, then to test it I held a piece of paper out in the air, and tried to slice it. The paper didn't cut like with my other knife that has a new factory edge.

I figured that it just needed more sharpening since this is the first time it's being sharpened. I used the sharpmaker on it for a while (several hundred strokes), and it still doesn't cut the paper. Does anyone know why this could be happening? Is it possible that really cheap knives will never become good enough to slice paper like this? Do you think I'm doing something wrong?

Thanks
 
Your probably not matching the angle - Not that you are doing anything wrong, but the original angle of the edge isn't matched to the two presets on the Sharpmaker. Using a magic marker will likely confirm this.

What you are experiencing is not uncommon. Once the angles on the blade match the angles of the S/M, you'll be in grand shape. And, by the way, if all you are using is the S/M, it's probably going to take you a long long time to remove enough steel for those angles to come together. Here, we always recommend using something else (such as a DMT benchstone) to set a thin back bevel, then refine and polish it with the S/M.
 
The most common cause is that the angle on your kitchen knife is higher than the Sharpmaker settings so you are not hitting the edge at all but regrinding higher on the knife. You can check this by coloring the edge and watching where the mark is removed by the Sharpmaker. It can take thousands of passes to regrind and edge on many knives. This reshaping is best done with an x-coarse benchstone, which takes a couple of minutes, and then sharpen with the Sharpmaker.

-Cliff
 
LIke Cliff said use a black magic marker on the very bottom of the edge and see where your rods are removing steel from the blade. Unless they are removing it at the very bottom you won't get the blade sharp.
 
I had the same experience, even with the diamond rods. I think its just really crappy steel, at least it was in my case. I can get my bm43 440c to pop hairs off, almost with out touching skin, well I was able to get it that sharp once. But I am pretty consistant with getting an edge that will easily shave the very fine hairs ont he back of my hand, I am talking THIN.

Anyways, I would give it another try with the magic marker it helps a lot, but if the steel is really crappy it could take your forever.
 
Thanks for the replies! If I understand correctly, you are suggesting that I need to do some reprofiling to make it 20 degrees on each side. I'm not sure that I want to try using a benchstone, but I've also read that I could try taping sandpaper to the Sharpmaker's rods and using that to reprofile. I would prefer this method, since it sounds like there's less of a chance I could screw up. Do you think this is a good idea?
 
You want to reduce the angle to less than 20 degrees per side so the Sharpmaker then hits only the very edge which makes it a much more efficient process. You don't need to be exact here as it is just a shaping process which is why anyone can easily do it by hand. However if you are concerned about aesthetics then try some coarse sandpaper on the 15 degree setting. Cut the sandpaper with the knife so the edge is dulled. Reprofile on the 15 degree settings until the knife slices paper evenly along its length. Now remove the sandpaper and hone on the 20 degree settings. The 20 degree honing should be less than a minute.

-Cliff
 
I bought sandpeper that is adhesive backed, I cut that into strips and stick them to the rods of the sharpmaker and bring the angle together with these. Then switch to the rods for honing, works great, I have done several knives in this way and the results when finished are what you'd expect from the sharpmaker
 
Cliff Stamp said:
You want to reduce the angle to less than 20 degrees per side so the Sharpmaker then hits only the very edge which makes it a much more efficient process. You don't need to be exact here as it is just a shaping process which is why anyone can easily do it by hand. However if you are concerned about aesthetics then try some coarse sandpaper on the 15 degree setting. Cut the sandpaper with the knife so the edge is dulled. Reprofile on the 15 degree settings until the knife slices paper evenly along its length. Now remove the sandpaper and hone on the 20 degree settings. The 20 degree honing should be less than a minute.

-Cliff
Click to expand...

What grit would you use for this?
 
For shaping use a really coarse grit, as in the lowest you can find, you want at least 80/100.

-Cliff
 
Would this be comparable to using a diamond bench stone for instance? Wouldn't the knife slice into the paper if used on the Sharpmaker rods, shouldn't sandpaper sharpening be done with trailing strokes?
 
Yes, the most coarse benchstones are in that range. No the knife won't slice into the sandpaper.

-Cliff
 
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