Thread: Shapton Lapping Question

OCD! You'll have to get a spec on the flatness of that abrasive film, and paper.

Personally I feel it is possible, through proper application, to exceed the flatness of dmt, just as it is possible to blow it with improper application.

similar to how we get .3- .5 micron edge widths (the width of the edge is form of "flatness") which is beyond the spec flatness of our stones typically.
(i did say similar)

Olivia, the granite would do the same as glass. This is a very tricky thing because the grits are rolling around, never embedding themselves as they do with cast iron lapping plates. But if you use the plate evenly it will last longer.

I really have a question to the guys who use granite as a lapping plate (never having used it myself) over the long haul do you find it effective? The reason I ask is because granite is a combination of usually 3 basic minerals and often more but basically quartz, feldspar and mica and the three are vastly different in hardness. It would seem the mica would start to degrade leaving pits in the rest.

Originally Posted by kevint

OCD! You'll have to get a spec on the flatness of that abrasive film, and paper.

Yes, it is very OCD. I'm not ashamed of that. And don't bring up the flatness of the abrasive film!! Now I want to find out....

Originally Posted by StraightRazorDave

Yes, it is very OCD. I'm not ashamed of that. And don't bring up the flatness of the abrasive film!! Now I want to find out....

No, OCD would be saying screw it and running out and buying the coveted Shapton lapping plate....... wait, I didn't just say that, did I?

Originally Posted by StraightRazorDave

Well I just got it. This thing is HEAVY!! Who would've thought a 9"x12"x2" piece of solid granite would be so heavy.

One side has a smooth surface while the other has a rough texture. Am I right to assume that the smooth surface is the one to use?

Stone weighs on average about 170 lbs/cu. ft. So heavy it is. At least it doesn't move around much when you lean on it.

Yup, smooth side up

Originally Posted by Bruce

Stone weighs on average about 170 lbs/cu. ft. So heavy it is. At least it doesn't move around much when you lean on it.

Yup, smooth side up

I actually put little rubber feet on the corners of the underside. Initially it was so it wouldn't scratch the counter top, but the plate is extremely secure and steady now.

Speaking of the mass of stones, I looked up densities and solid granite is about 2691 kg/cubic meter, which is 167.65 lbs/ cu. ft. rounded, so 170 was pretty spot on Bruce! I did some measurements and my granite tile should be about 9.7 kg or 21.4 lb (rounded). How's that for OCD??

Originally Posted by thebigspendur

I really have a question to the guys who use granite as a lapping plate (never having used it myself) over the long haul do you find it effective? The reason I ask is because granite is a combination of usually 3 basic minerals and often more but basically quartz, feldspar and mica and the three are vastly different in hardness. It would seem the mica would start to degrade leaving pits in the rest.

I don't know any of us that are using it as a "lapping plate" per se since we're not using lapping compounds on the surface of the actual granite plate. Instead, at least for me when I've used mine, it's simply a flat surface used for lapping film and wet/dry so I should think there would be no degradation.

Chris L

Ok, I just caved and bought a DGLP!!!! I shouldn't say caved since I really always have wanted one.

I'm still going to use my granite tile for non-Shapton lapping if I need it and for honing using my micro-abrasives. I've actually sharpened a kitchen knife using the tile and micro-abrasives.

Long story short, do NOT resist the urge of the Shaptons, it's powerful. I can't wait to try them all out.

I hate to say it, Dave, but you didn't buy the
complete set of hones (ignoring for the time
being the pond and holder). I don't see the
30k on that list...

- Scott

Originally Posted by sebell

I hate to say it, Dave, but you didn't buy the
complete set of hones (ignoring for the time
being the pond and holder). I don't see the
30k on that list...

- Scott

Oh believe me, the 30k will be mine in the future. My Nakayama Maruichi will have to do for now after the 16k.....I'll survive! Fendrihan has a sale on the holders and seeing as they're based in my home town I'll probably end up picking up one locally soon.