shapton 8000 hone

[peter kolb]

I have only one shapton hone and it is a 8000 grit.
I was using it for the first time today on a 35 mm number three
gouge. I was trying to get a polish on the blade. Number of
issues. Prior to using the 8000, I sharpened on a hard translucent
hone. After removing the burr the gouge was sharp. Probably
would get sharper if I stroped the edge, which I did not.
Went to the 8000 and after a few minutes the Shapton had
black streakes where the hone abraded the gouge. The streaks
started to build up. I understand that the streaks are the
material being removed from the gouge. Does the black streaks
slow the sharpening process? How do I get rid of the streaks?
Before taking a break for super the gouge was almost polished but
the edge was dull. Not sure if there was a burr but I did not remove
it; when I tested the edge.
What am I doing wrong. Thanks for your help. Peter

[Jim Koepke]

I have only one shapton hone and it is a 8000 grit.
I was using it for the first time today on a 35 mm number three
gouge. I was trying to get a polish on the blade. Number of
issues. Prior to using the 8000, I sharpened on a hard translucent
hone. After removing the burr the gouge was sharp. Probably
would get sharper if I stroped the edge, which I did not.
Went to the 8000 and after a few minutes the Shapton had
black streakes where the hone abraded the gouge. The streaks
started to build up. I understand that the streaks are the
material being removed from the gouge. Does the black streaks
slow the sharpening process? How do I get rid of the streaks?
Before taking a break for super the gouge was almost polished but
the edge was dull. Not sure if there was a burr but I did not remove
it; when I tested the edge.
What am I doing wrong. Thanks for your help. Peter

Am I correct in guessing the Shapton is a water stone?

Was the "hard translucent hone" an oil stone? Did you make sure to get all the oil off of the gouge before moving to the Shapton?

Gouges are particularly difficult to sharpen. My process on water stones is to lap them sideways while rotating them. I will also move them on an angled course to help create an edge. Because oil stones are harder, they are actually easier to use when sharpening gouges. If extreme care is not being used, my water stone will often get a "gouge" line.

The black lines on a water stone is caused by the swarf. The swarf is the breakdown of the stone and the material being abraded by the stone. It is actually a compound that contributes to the cutting and polishing.

When honing a flat blade, I will almost always lap the back for a few strokes and then hone the bevel. The water and swarf climbing up the back of the blade lets me know the bevel is flat on the stone.

More burr is created on the pull stroke than on the push stroke when sharpening.

To trouble shoot what is actually happening in your case, seeing the blade would be the best way to figure it out. If the edge is rounding, then the blade is being rocked during the honing. If there is a flat step, then the blade is not being held at the correct angle.

Reading Chris Pye's first book of two on wood carving covers sharpening gouges extensively. He recommends oil stones and stropping. After a few divots have been put into my water stones, I can see why.

jim

[Sam Takeuchi]

It's a Shapton Pro #8000, right? Do you happen to be using that #8000 stone dry or with oil? Because if you are simply water, black swarf will safely swim away and if it gets too black, just flush it with water. If it's stuck to the surface, lapping it will, but #8000 isn't the kind of stone you spend a lot of time on, if you are getting so much swarf, maybe you are trying to remove too much metal?

Either way sounds like you are doing something really wrong there. You should've removed burr if you wanted to get any idea if edge is sharp or not.

If your technique is proper, Shapton #8000 should create really sharp edge already. Since you can sharpen it on another stone, assuming your technique is fine, what are you doing to the #8000 before and when you use it? Also what stones are you using prior to Ark stone and Shapton?