Thread: Norton 4000/8000 prep

They had none local. I guess I have to go online. But than I risk getting one that's not flat.. Brother, why isn't this easy.
Someone should post a video flattening a Norton with sandpaper.

Originally Posted by randydance062449

A newb stopped over to my place this weekend with a new DMT8C and a new Norton 4/8. We tried lapping the Norton with the DMT but ran into a problem. The DMT was not flat!It was high on one side!

I had to resort to using a 180 grit sandpaper to flatten the Norton and then used some finer sandpaper grits to finish the job.

Not all DMT's are flat! Check them first with a straight edge.

BTW, I use sandpaper to lap my Norton and have not had a problem. YMMV

Randy......Thanks for notifying us of this issue with the DMT8C! That's of great concern to me. I own one as well and use it exclusively for lapping my stones. It's such a concern to me that I called a local guy I know that has a decent sized machine shop and asked if he could check this plate for me. Most likely this Friday or next week, he and I are going to slap that DMT8C on a granite inspection plate and put it to the test. I'm going to be looking just about like this if it's not as flat as it should be:

I'm also going to put the pencil grids on my Norton 4000/8000 and lap again. I wondered why when I'd have the grid, it would wear the Norton sides down in the middle quite a bit sooner than the ends. I assume that once all grid lines are gone, if I redraw the grind and lap again, it should NOT wear away the center quicker than the ends!!! If it does, then how could MY DMT8C not be warped as well. I'll be steamed.

This may be what I get for not keeping it simple like you and Alan do!

Originally Posted by Chrisl

...
I'm also going to put the pencil grids on my Norton 4000/8000 and lap again. I wondered why when I'd have the grid, it would wear the Norton sides down in the middle quite a bit sooner than the ends. I assume that once all grid lines are gone, if I redraw the grind and lap again, it should NOT wear away the center quicker than the ends!!! If it does, then how could MY DMT8C not be warped as well. I'll be steamed.

This may be what I get for not keeping it simple like you and Alan do!

I can try to answer this one from a tool room/machining perspective. The following applies to hand-lapping steel (on a steel/iron lapping plate), I assume it also applies to hand-lapping a hone.

The edges of the workpiece (hone) tend to get more lapping on the leading and trailing edges then the center using a back and forth stroke. Using a circular or figure-8 stroke will tend to wear all edges a bit faster than the center. The way to minimize this effect slightly is to turn the hone 90 degrees on the lapping surface every so often (or at least 180 degrees). In practical terms using a circular stroke and alternating it's direction every so often will be just as good as using a figure-8. It's also good to mix in back and forth strokes N-S and E-W.

After you get rid of your first pencil grid-marks it is also good to remark it and lap again to eliminate some errors from the first lapping.

"How flat is flat enough?" is the million dollar question and a good one to answer. We already know that +/-.001" over an 8" surface is good enough for a razor. How about +/-.001" over 1 inch? Sounds like a good project for someone with access to a surface plate and a dial indicator...

As far as eliminating all the pencil marks goes: the average thickness of many pencil marks is between 4 to 17 nanoinches (0.000000004" to 0.000000017"), four billionths of an inch is pretty darn good!!! (but not a real issue when compared to the DMTs +/-.001")

I'd really be interested in seeing the results from the machine shop inspection.

Originally Posted by Sticky

I can try to answer this one from a tool room/machining perspective. The following applies to hand-lapping steel (on a steel/iron lapping plate), I assume it also applies to hand-lapping a hone.

The edges of the workpiece (hone) tend to get more lapping on the leading and trailing edges then the center using a back and forth stroke. Using a circular or figure-8 stroke will tend to wear all edges a bit faster than the center. The way to minimize this effect slightly is to turn the hone 90 degrees on the lapping surface every so often (or at least 180 degrees). In practical terms using a circular stroke and alternating it's direction every so often will be just as good as using a figure-8. It's also good to mix in back and forth strokes N-S and E-W.

After you get rid of your first pencil grid-marks it is also good to remark it and lap again to eliminate some errors from the first lapping.

"How flat is flat enough?" is the million dollar question and a good one to answer. We already know that +/-.001" over an 8" surface is good enough for a razor. How about +/-.001" over 1 inch? Sounds like a good project for someone with access to a surface plate and a dial indicator...

As far as eliminating all the pencil marks goes: the average thickness of many pencil marks is between 4 to 17 nanoinches (0.000000004" to 0.000000017"), four billionths of an inch is pretty darn good!!! (but not a real issue when compared to the DMTs +/-.001")

I'd really be interested in seeing the results from the machine shop inspection.

Thanks for the info. I appreciate it. And....oh yes, I'll be reporting my findings here after the machine shop inspection, believe me. If the DMT8C is unacceptably off, I don't think I'll talk to Howard at The Perfect Edge about it since I bought it a few months ago and he didn't manufacture the plate, I think I'd be mailing it back to DMT directly. I do want to give the D8C the benefit of the doubt though and I don't want to be too quick to judge.

Just to make sure I am not giving anyone the wrong impression I want to make it clear that I am not against the DMT hones. I just thought that it was sufficiently unusual to warrant a post. Perhaps someone else may have difficulties in the future like a few guys have had problems with the Norton 4/8.

Based upon my own experience and that of others here it would be reasonable to conclude that most hones are just fine but it would be wise to "trust but verify".

I just posted this in the Flattening with sandpaper thread. I found this thread so helpful and on my topic I thought Id post here too as you are all on the trail I traverse.

This is a helpful post. Thank you. I'm using a glass bed and 1000 grit paper. I see the 8000 side makes a nice yellow slurry. I'm not sure what I'm doing and I was washing the slurry off the stone and the paper and re-honing. Maybe I should use the slurry. Any way, I have done the 4K and the 8K using one piece of paper. Moving my stone back and forth with no down ward pressure. I applied a little pencil to the 4K side to watch it remove. It never did come out completely and I had thought I applied it lightly. I was wondering. How much lapping of stone should I do? How can I reference or determine a flat enough surface to simply sharpen my razors? I don't need to get too carried away just yet. I simply want a good surface to start my learning and sharpening process.

Hey guys... I am clearly new here. I was wondering a stupid quesiton. What is a "DMT D8C"?

The DMT D8C is a diamond hone made by DMT, it is their 8 inch long "Coarse" hone and is rated at 325 grit.

All DMT hones are guaranteed to be flat to within a tolerance of .001 inches over the length of the hone, so they make great lapping plates for keeping your other stones flat.

There are a full line of hones from DMT that go; 120, 325, 600, 1200, and 8000 grit

Originally Posted by geoffreyt

I just posted this in the Flattening with sandpaper thread. I found this thread so helpful and on my topic I thought Id post here too as you are all on the trail I traverse.

This is a helpful post. Thank you. I'm using a glass bed and 1000 grit paper. I see the 8000 side makes a nice yellow slurry. I'm not sure what I'm doing and I was washing the slurry off the stone and the paper and re-honing. Maybe I should use the slurry. Any way, I have done the 4K and the 8K using one piece of paper. Moving my stone back and forth with no down ward pressure. I applied a little pencil to the 4K side to watch it remove. It never did come out completely and I had thought I applied it lightly. I was wondering. How much lapping of stone should I do?How can I reference or determine a flat enough surface to simply sharpen my razors? I don't need to get too carried away just yet. I simply want a good surface to start my learning and sharpening process.

The pencil marks do not go any deeper than the surface, you'll have to lap the stone until they are all gone.

1000 grit paper may be too high for this. I don't personally use paper so I may be wrong, but I do know that it'd take me a while to properly lap a stone with my DMT 1200, and I suppose sandpaper should be even slower.

This ought to be a part of the learning experience; don't short change any step in the honing process, you'll just end up doing it like you should have the first time, later.

This actually opens the door for me to pass on my favorite piece of advice from my father. "If you're gonna f@&%in' do something, do it right". (I intend no angry tone with this quote, that's just the way he used say it when we worked together in his machine shop around tools that will maim or kill you if you don't use them correctly).

That said, most stone are "flat enough" . But for learning, you want to decrease the variables that could cause problems. So, I say keep lapping.

Originally Posted by Russel Baldridge

The pencil marks do not go any deeper than the surface, you'll have to lap the stone until they are all gone.

1000 grit paper may be too high for this. I don't personally use paper so I may be wrong, but I do know that it'd take me a while to properly lap a stone with my DMT 1200, and I suppose sandpaper should be even slower.

This ought to be a part of the learning experience; don't short change any step in the honing process, you'll just end up doing it like you should have the first time, later.

This actually opens the door for me to pass on my favorite piece of advice from my father. "If you're gonna f@&%in' do something, do it right". (I intend no angry tone with this quote, that's just the way he used say it when we worked together in his machine shop around tools that will maim or kill you if you don't use them correctly).

That said, most stone are "flat enough" . But for learning, you want to decrease the variables that could cause problems. So, I say keep lapping.

You are exactly right. "do it right". Thats why I'm posting. I don't want to fall short of the best job I can do. I simply need to realize when that occurs. I will get some more coarse sandpaper and keep on it till the pencil marks go away. Thanks. Im seeing the light I think.