Thread: Did I lap properly?

Originally Posted by Utopian

The razor's edge passes over the long sides of the hone, that's why you bevel those edges. Since the razor should never reach the ends of the hone (the short sides), there is no need to bevel those edges unless you prefer it aesthetically.

I realize when doing a rolling x a rounded edge is nice.

However there is nothing wrong with using the short dimension to hone on as well(using the whole stone rather than just the usual path)

As well, the edges need to be eased over to prevent chipping and eliminate the risk of cutting yourself on the sharp edges

I'm a big fan of rounding all the corners. I find myself getting (stupidly) complacent with my razors sometimes, and find myself thinking, "I should have folded that and set it down before I ...". The less opportunity you have to screw up your blades, the better luck you will have.
J.

hey guys, quick question... I have an 4k/8k norton and I have norton's lapping stone. I've gone through the pencil matrix thing several times and yet my razor still doesn't seem to be lying flat on the surface. So I assume either the hone isn't actually flat, the razor isn't straight or both?

My lapping process is:
1) draw the pencil matrix
2) hold the lapping stone in my left hand, motionless over the sink
3) hold the hone in my right hand
4) place the hone flat against the lapping stone and move it in smallish circles until the pencil matrix is gone, occassionly rinsing the residue off under water.
4.1) repeat if neccessary.

needless to say my razor won't even cut arm hare what am I doing wrong?

Your stones should be sitting on a flat hard surface like a counter top so they are flat while you're rubbing the top stone into the stone underneath. That's sounds like a major issue with your lapping to me. Your hands are probably moving even slightly and contouring the stone a little bit. There is a lapping 101 wiki on this site.

Originally Posted by Disburden

Your stones should be sitting on a flat hard surface like a counter top so they are flat while you're rubbing the top stone into the stone underneath. That's sounds like a major issue with your lapping to me. Your hands are probably moving even slightly and contouring the stone a little bit. There is a lapping 101 wiki on this site.

Thanks Disburden, but that's where I'm confused. In the wiki is shows him holding his other stone in his left hand and the other hone in his right and moving in circles like I was doing.

Quote from the Hone Lapping 101 wiki:

"To use my DMT hones for flattening, I usually hold the DMT in my left hand and the hone in my right. I make circles with the hones under a stream of running water in the sink. "

Originally Posted by jammyman34

hey guys, quick question... I have an 4k/8k norton and I have norton's lapping stone. I've gone through the pencil matrix thing several times and yet my razor still doesn't seem to be lying flat on the surface. So I assume either the hone isn't actually flat, the razor isn't straight or both?

My lapping process is:
1) draw the pencil matrix
2) hold the lapping stone in my left hand, motionless over the sink
3) hold the hone in my right hand
4) place the hone flat against the lapping stone and move it in smallish circles until the pencil matrix is gone, occassionly rinsing the residue off under water.
4.1) repeat if neccessary.

needless to say my razor won't even cut arm hare what am I doing wrong?

I prefer having a small constant flow of water clearing away the slurry during lapping. Assuming that your Norton lapping stone started flat and it has completely removed the grid, then the hone should be flat. You can check it by holding a straight edge up to it and see if you see light in the gap.
As far as the razor being straight, that seems to be rare thing in my experience. That is the reason that the x-stroke, 45 degree stroke, and rolling-x are so frequently recommended around here. They ensure that the entire length of the edge contacts the hone at some point during the stroke.

Thanks Utopian, I tried the straight edge test and it appears that lengthwise it's not flat, when I hold the far sie down there appears to be just about a milliemeters worth of space, maybe half a MM...

So, I gotta tell ya I'm a little ****ed. I've matrixed and lapped that damn thing maybe 15 times already using the norton flattening stone. If that stone isn't flat to begin with then why the heck are they selling it that way? I mean if I have to ensure that the flattening stone is flat using the sand paper method as described in the wiki why wouldn't I just do that for the hone?! What's the damn point of buying a flattening stone!!

I suppose using a straight edge on the flattenig stone will work for testing it's flatness as well?

Thanks again, sorry for my complaining...

OK, take a deep breath, chant a mantra, and consider...

It IS possible that your lapping stone is no longer flat.

Over time if you are not using uniform pressure on the entire surface of the lapping stone, it can become distorted. I lap as described previously with the hone in one hand and a DMTXX in the other. While doing that I regularly swap which way I am holding each of them. Say I'll do twenty circles and then swap the hone end for end in my hand. Then I'll do twenty more and swap it again. I also occasionally swap the DMT end for end as well. I do this because the pressure from my hands is not likely creating uniform force between the hone and the plate. By swapping the regions that are coming in contact with each other, I am hoping that the wear is averaged out. Perhaps your lapping stone started flat but uneven pressure has worn one end more? I'm not accusing, I'm speculating!

At this point, it sounds like you do need to lap your lapper with sandpaper. Once you know it is flat, go back and try lapping your 4/8k again, this time occasionally swapping ends. Try to use uniform pressure. Don't use a lot of pressure. Use a light but constant stream of water. Finally, don't use the Norton lapper on anything but the 4/8k, especially don't use it on a natural or barber hone as they are too hard and the wrong size. Once you have the lapper flat and you are diligent about balancing the pressure and contact between the lapper and the hones, they should continually be lapping each other. In other words, I believe if you are using the Norton lapping stone correctly, it should remain perfectly flat. If it is not, then you are likely doing something wrong.

Good luck!

Thanks again Utopian... looks like I'm off to Lowes to get some wet/dry sandpaper and start this party over