Thread: Lapping new Shapton Glass stones...with sandpaper?

Just ordered a set of 4K/8K/16K Shapton Glass stones. I know I need to lap them & chamfer the edges before the first use.

Here's the thing: I hate lapping stones. I don't know how people use them. They take soooo long. I've tried the Norton and Naniwa lapping stone on both my Norton 4K/8K and Naniwa SS 12K. I've found it's 10x faster/easier just to throw some sandpaper down on my kitchen counter and be done with it. The weight of the stone plus a little elbow grease will knock them flat in no time.

I've been using 220 grit sandpaper. Is that sufficient for Shaptons or should I use a coarser or finer grit?

Originally Posted by supersco

Just ordered a set of 4K/8K/16K Shapton Glass stones. I know I need to lap them & chamfer the edges before the first use.

Here's the thing: I hate lapping stones. I don't know how people use them. They take soooo long. I've tried the Norton and Naniwa lapping stone on both my Norton 4K/8K and Naniwa SS 12K. I've found it's 10x faster/easier just to throw some sandpaper down on my kitchen counter and be done with it. The weight of the stone plus a little elbow grease will knock them flat in no time.

I've been using 220 grit sandpaper. Is that sufficient for Shaptons or should I use a coarser or finer grit?

The Naniwa and Norton lapping plates aren't all that, I agree with you..
Try a Shapton DGLP or a Atoma 400 and you will see what proper lapping can be like

But to the point then;
Yes, you could use 220 grit sandpaper on your Shapton's.
Personally I would go a tad higher though.
The Shapton's do not need all that much lapping in the first place, so why not go with say 400 or even grit?
That will leave you with a surface fine enough to go straight at it with your razors and at the same time be reasonably fast on the stones.
On stones in the finer range like your 16K some will use a progression of lapping media.
That will secure speed and a fine surface at the same time.

For my Shaptons (Pro versions) I tend to use the Shapton DGLP (325 grit) every now and then.
Works like a charm, but it is a tad on the pricey side if that is of any concern.

I have the DMT 325, the Atoma 140 and the Atoma 400, and I still find myself laying a sheet of 400 grit wet/dry sandpaper on a countertop and lapping all my stones, all the way to a Shapton GS 30K, that way. I've never had a problem with it. I might use the Atomas for my 1K stones, but seldom have to use them anyway.

Originally Posted by Birnando

For my Shaptons (Pro versions) I tend to use the Shapton DGLP (325 grit) every now and then.
Works like a charm, but it is a tad on the pricey side if that is of any concern.

Great response, I will pick up some 400 grit wet/dry sandpaper today while I'm out. I looked at the Shapton DGLP, but after dropping $400 on the set of three stones plus a holder, I couldn't afford it. I will keep that in mind or a Atoma 400 for the future though. Thanks!

Originally Posted by ace

I have the DMT 325, the Atoma 140 and the Atoma 400, and I still find myself laying a sheet of 400 grit wet/dry sandpaper on a countertop and lapping all my stones, all the way to a Shapton GS 30K, that way. I've never had a problem with it. I might use the Atomas for my 1K stones, but seldom have to use them anyway.

Good to know! I'll get some 400 grit wet/dry today to be ready when the stones arrive.

The voice of Dissent:

No way, no how, would I use anything but a Diamond plate of some type on most Hones..

The Norton, Naniwa, and Sandpaper release grit when lapping, sorry they just do, the idea of honing a razor, and then dinging the fine edge on an errant piece of embedded grit in one of the hones drove me to buying a DMT 325, doesn't really matter which Plate you get but if you are going to be honing it is a solid investment..

I like the DMT because it is the most useful to me besides just for lapping

I'm with Glenn on this. I must confess that I have never used sandpaper to lap. Going for the $ for expensive stones I thnk it is prudent to go a few more and get a DMT D8C 325 at minimum, or if you want to 'go for the gusto' the Atoma 400 & 1200. The Atoma plates are significently more $ but they really deliver the goods IME.

Fair point about releasing the grit, Glenn. That might be the only reason I would ever consider spending more money on a lapping stone again. Do the DMT 325 plates or Atoma 400 need lapping before taking them to the hones? If so, how do you lap them?

If I can only afford one lapping stone, which one should I invest in: DMT 325, Atoma 400, or Atoma 1200?

You cannot lap a diamond plate. They are supposed to be flat as can be from the factory. IME this is not always the case with the DMTs but the Atoma is more precise, again, IME. Not that the DMT is way out. I did return one for a replacement because it wasn't in 'tolerance', but of the few I have most are acceptable. The DMT 600 is perfect. I've only one Atoma, a 1200, and it is on the money. I've heard all of the are.

Edit; When I say "the" 600 is perfect, I mean "my" particular 600, not necessarily in general. + 1 on the Atomas, worth the $ if lapping is what you're doing. For doubling as a knife sharpener or for razors I'm not so sure. I only have the 1200 but it is so aggressive, due to the way the diamonds are bonded, that I think the DMT would be more suited to double duty. IMHO.

Originally Posted by JimmyHAD

You cannot lap a diamond plate. They are supposed to be flat as can be from the factory. IME this is not always the case with the DMTs but the Atoma is more precise, again, IME. Not that the DMT is way out. I did return one for a replacement because it wasn't in 'tolerence', but of the few I have most are acceptable. The DMT 600 is perfect. I've only one Atoma, a 1200, and it is on the money. I've heard all of the are.

+1 on the Atoma's.
I have 140, 400, 600 and 1200 grit plates.
All flat as a pancake!
That said, so are my 3 DMT's as well