First carving knife sharpening difficulties

[brown365]

I am trying to sharpen a new knife. I have got the basic shape of the blade down and started to move on to an extra fine, interrupted diamond stone, which is also brand new. After a few passes over the stone in the same manner I had done on the coarser grits, the edge seems to flatten out; getting duller. I went back to a coarser grit, got an edge back, and tried again, and the same thing happened on the diamond stone again.
I tried more and less pressure, dry and with water to have the same thing happen to the edge.

Am I doing something wrong? Is it just the diamond stone "breaking in"?

[Tom-H]

I am by far not an expert on sharpening knives, but try using the strop after the last diamond series; there may be a "wire edge" hanging around that needs to be removed.

Tom H

[Gulf Coast Handyman]

I agree with Tom.

Dave

[carvingbarn]

Stropping may be your answer. Some times new carvers will turn their resists as they lift the blade off the stone rather than lifting the blade strait up off the stone. This rounds the edge. It can also be a issue when Stropping. Make sure you lift the blade up at the end of your pass on the strop. Do not role it as you come off. This was an issue for me when I started.

[richipper]

I would say it is probably more the breaking of the diamond. Mine were very aggressive at first too. I do a back and forth motion on the blade at as close to zero angle. But don't stop with x-fine. I go to a ceramic stone the strop for the final polish and edge.
Can you get a picture of the edge? What type of knife is it? Some have very different steel quality and may affect the edge.
I have a Butz, flexcut and Body that required different prep.
Let us know how you solve you problem.

Richard

[wDonkey]

sharpen your kitchen knives (or anything you can find) on those stones to try to break them in faster. they are agressive when they are new.

[AlArchie]

It's really difficult to explain sharpening verbally, but I've found the old Boy Scout method to be a good starting point.

1. Lay yor blade flat on your stone.
2. Raise the back of the blade about the thickness of a dime.
3. Push the blade acros the stone as if trying to cut a thin slice off the stone
making sure to hold that same angle.
4. Do 10 repetitive strokes all in the same direction.
5. Turn the blade over, raise the back that 10 cent level, and push through 9
strokes.
6. Flip the blade again and do 8 strokes. etc, etc etc. down to one stroke on
each side.
7. Now it's time to strop.

I'd recommend only "pushing" the blade rather than a circular motion as it is easier to hold that 10 cent angle that way. Eventulally you will be able to get and hod the proper angle without even thinking about that dime. I call this muscle memory.

Al

[Nomad]

I can only guess at what might be happening. Perhaps that sharpness you feel at first is a large burr on the edge and when you finish with the finer stone, the burr is smaller and so feels "less sharp."

[Stan Curtis]

I have used diamond laps and oilstones, both of which can do a reasonable job. Wheel grinders and belt sanders are still used to shape blades and for rough beveling. But the finish sharpening is done on a flat stone tile with wet/dry abrasive paper. I progress from 220 to 500 to 1000 to 1200 grits. The final stone is a white (approximately 8000) ceramic. Use a magnifier at the later steps to check what you are getting, especially when the vaunted wire edge starts forming. Then comes the polishing and honing. Use a floppy wheel to get the polish and hand strop with a firm supported leather. The first strop has compound on the rough side; the second has no compound on the smooth side. Ten strokes each side of the blade, then nine, etc. down to the final one. Takes a bit of time but a fine edge results that rarely needs to be stoned again. And then only on the ceramic stone. That's my procedure that evolved over time and it works well for me. Patience is the main virtue.