Thread: how to avoid scratch blade while honing

Hey, does anyone have any advice on how to avoid scratching the blade while honing? Of course there are always some on the spine, but those are relatively easy to polish off, and can be prevented with tape if you care enough. But what I've been having a problem with are little (say, .5cm) scratches starting at the edge and running perpendicular to the edge up the blade face. I particularly have this problem on the DMT hones, which I sometimes use as bevel-setters. Id ont have the problem so much on my other hones - belgian and japanese naturals - but sometimes. What's wierd, though, is I thought that the blade face doesnt actually contact the hone anyway (except on a full wedge, of course), so I just dont see how it happens.

The DMT-caused scratches really have me stumped - I have tried to go very carefully and still end up getting 1 or 2 - and they can be fairly deep, and a pain-in-the-ass to get out, often requiring significant sanding. Sometimes, though, they are light and polish off easily. The ones on the naturals I think, might be caused by swarf/steel in the slurry, i.e. my not rinsing often enough.

Any help would be much appreciated.

DMT releases loose diamond particles which can scratch the blade.
I would suggest less pressure when honing, and may be switching to Naniwa which definitely does not have the problem.

A grind (not wedge) and you get scratches on the blade face between the bevel and the spine. I don't have any idea! But, I do have a suggestion.

You are doing something that results in scratches on the blade face. It would make sense that whatever action it is will be repeated in varying degrees of severity. In other words, the action might scratch deeply once or twice during a honing. But, that action might be repeated 15 times, but light enough that you aren't seeing the scratches.

My suggestion is to paint the entire blade with a black magic marker. (Comes off with alcohol.) When honing, after every pass or two examine the blade face.

Catch it in the act!

Have you broken in your DMTs with a plane blade or something of that nature to knock down the high spots as the company suggests ? I've yet to have any type of hone scratch the face of a blade and I've honed quite a few on many different hones.

I take a long shanked screw driver and rub the plate down vigorously to break them in. I pay special attention to the edges where a divot could cause micro chipping.

Any chance you can capture in a picture? I am having a little problem understanding scratching on the blade when only the spine and edge or bevel is touching the stone. What type of honing motion are you using? Are you wiping the blade with a rag or towel multiple times and it might have slurry on the rag or or towel? Are the scratches really apparent or just show up under a bright light?

Thanks,

Lynn

I know exactly what you mean. I've seen this happen too with DMT's. It's partly beacuse the spine has already some hone wear or is less wide resulting in a less steep angle for the edge. So when you the razor flat on the DMT to hone you're actually putting more of the edge and the side of the razor on the hone resulting in higher scratches. To much pressure on a DMT will enhance this too. Also don't forget that DMT's have no play. They are a rock hard, solid piece of steel. Naniwas are softer and Shaptons harder but still have some feedback and play. The only option to remedy this with that particular razor is to add tape so the spine widens in width resulting in a steeper angle so only the edge is actually touching the hone. Or just not use the DMT or any diamond abbrasive hone.

I've had this happen on my lower grit hones sometimes when swarth builds up - Norton 220, Naniwa 400, and can even happen on a Norton 1k. Rinsing the hone frequently, using less pressure, and taping all seem effective.

hey guys, thanks for your responses.

I have a bit of a new theory - it might be happening on the edge of the hone, like if I hone off the edge, so the blade edge goes all the way off the face. And then the corner/edge of the hone can make contact with the blade face. And the force/contact would only be at one point, and would be perpindicular to the edge, and starting at the blade edge (as I described), because you have the edge pressed down and making contact. I just tried honing two blades and was very careful not to go off the edge, and didnt have any scratch problems. Not yet conclusively solved, but I am optimistic.

I dont have the problem with any other hones - I wonder if it is because the DMT's are not beveled, whereas my natural hones I have beveled myself? Plus, of course, the edges are so hard.

Lynn, I'll see if I have one where I havent worked out the scratches. The scratches can be light, but the ones that worry about me are quite visible and noticeable. Usually they will polish out or sand out with 2000-grit, but occasionally not and then it kills me. As for honing motion, I use different strokes - but mostly X-strokes and "straight" strokes for the toe and heel. I sometimes use "half-strokes" (or saw them called that), where I dont life the blade face and there is an edge-leading away-stroke followed by an edge-trailing toward-stroke, and I thought that might be the problem, but then did have some scratches on regular, careful, x-strokes.

Jimmy - I havent broken them in, and I didnt know that you were supposed to. As I also use my DMTs for lapping and slurry-making, I wonder if that achieves the same effect?

And yes, these are lower-grit DMTs - 325, 600, 1200.

Thanks again, all, for your thoughts/help.

Originally Posted by Mijbil

Jimmy - I havent broken them in, and I didnt know that you were supposed to. As I also use my DMTs for lapping and slurry-making, I wonder if that achieves the same effect?

And yes, these are lower-grit DMTs - 325, 600, 1200.

Thanks again, all, for your thoughts/help.

This is your problem. At first Broke them in (how to do make search in here)then use with some amount of soup.gl