Lapping Shapton glass stones

[john snowdon]

After searching the archives, I still have a question about lapping the new "Woodorker's Set" of Shapton GlassStones I recently purchased from Craftsman Studio. The set I purchased includes 1000, 4000, 8000 stones but not the Shapton lapping stone due to cost. Instead, I purchased a DMT Dia-Flat Lapping Plate from Amazon. It was not until it arrived I realized it is a 120 grit plate and I'm wondering if that is too coarse for lapping my glass stones. When I read the Q/A section on Amazon, question #1 was "can I use this for lapping my Shapton glass plates". The 2 answers were yes but I'm concerned the 120 is too aggressive. Your thoughts are greatly appreciated!
John

[Andrew Hughes]

I think your going to be alright.Even if it's aggressive now it won't stay that way for very long.All the diamond plates mellow out if you have time to use them.
I also have the Shapton stones

[john snowdon]

Thanks, Andrew! I appreciate your help.

[john snowdon]

Andrew, as you mentioned you have Shapton, may I ask what grits you use and how often you have to flatten them?
Thanks, John

[Malcolm Schweizer]

I have the Shapton Glass stones, as well as Norton, Chosera, and others. For many years I have used the DMT diamond lapping plate, and it works great. I do find it a bit agressive, and I had always used a finer DMT diamond stone to touch up the stones above 4000 grit and get the scratches out that were left by the DMT. I then realized that those scratches really don't change the grit of the stone- they're just scratches, so they don't really matter. You can also use your nagura stone to dress the surface before sharpening if the scratches bother you.

I finally got hold of an eBay deal on the Shapton diamond stone, and wow- that thing is awesome. It flattens faster and is a finer grit than the DMT. I suspect the channels that carry away the slurry and keep the diamonds exposed are part of why it cuts faster. I'm very pleased with it, but boy it's a hard expense to justify. If I didn't sharpen knives and tools on the side for money, I probably wouldn't have even sprung for the used price on the Shapton glass diamond stone. It is, however, one heck of a nice flattening plate.

[Andrew Hughes]

Andrew, as you mentioned you have Shapton, may I ask what grits you use and how often you have to flatten them?
Thanks, John

Alot but I'm not really using my diamond stone to flatin.Its to keep the surface clean so I can see where I making contact with the blade.Im a side sharpener so I use the whole surface.Heres how my stone looks right now.
This is the stone I use the most.
Good luck with your set up I think it's going to be great!

[john snowdon]

Thanks, Malcolm and Andrew. Off to the shop to flatten some stones and tune up some new chisels!

[Don Slaughter]

John, I've had that same set of stones, also bought from Craftsman Studio (when it was here in San Diego), for many years. I've always used 120 grit wet/dry sandpaper on a piece of marble to lap my stones and it works perfectly. I just mark them with a pencil and rub them 'til the marks are gone. Don't worry about the grit being too aggressive ....it won't affect the sharpening process at all. My stones last for several sharpenings before needing lapping....I use a coarse diamond stone to prep edges for the shaptons if the edge is in bad shape. I use the shaptons for sharpening...not for shaping or rehabbing an edge.
good luck

[Patrick Chase]

I finally got hold of an eBay deal on the Shapton diamond stone, and wow- that thing is awesome. It flattens faster and is a finer grit than the DMT. I suspect the channels that carry away the slurry and keep the diamonds exposed are part of why it cuts faster. I'm very pleased with it, but boy it's a hard expense to justify. If I didn't sharpen knives and tools on the side for money, I probably wouldn't have even sprung for the used price on the Shapton glass diamond stone. It is, however, one heck of a nice flattening plate.

The Shapton plate is also extremely flat (I've forgotten the spec, but it's better than any other plate I own) and uniform, with no "rogue grits" a la DMT. The downside for that flatness and uniformity is that the diamond particles are bonded via a resin-based coating instead of electroplated, so they're even more susceptible to stripping/removal than a traditional diamond plate. That's why Shapton says to never use it on metal tools or on stones below #500. Shapton will strip and recoat it for you if needed, but that costs almost as much as a new one.

I've had mine for a few years with no signs of wear, but I'm very careful with it. I only use it when I need extremely tight flatness control (for example consecutive stones need to be ~identical to each other when working blade backs or else you end up doing a lot of extra work to "reconcile" the differences).

[Malcolm Schweizer]

The Shapton plate is also extremely flat (I've forgotten the spec, but it's better than any other plate I own) and uniform, with no "rogue grits" a la DMT. The downside for that flatness and uniformity is that the diamond particles are bonded via a resin-based coating instead of electroplated, so they're even more susceptible to stripping/removal than a traditional diamond plate. That's why Shapton says to never use it on metal tools or on stones below #500. Shapton will strip and recoat it for you if needed, but that costs almost as much as a new one.

I've had mine for a few years with no signs of wear, but I'm very careful with it. I only use it when I need extremely tight flatness control (for example consecutive stones need to be ~identical to each other when working blade backs or else you end up doing a lot of extra work to "reconcile" the differences).

Thanks for that reminder. I was flattening some irons the other day and thought about trying the shapton diamond plate, but decided it was way too expensive for that. I forgot about that warning, but I did remember something about not using it below 500 grit. Glad I didn't try that.

[john snowdon]

Thanks, Dan. I've contacted Craftsman's and left a couple of messages as I am seeing my 8000 stone become chipped at all 4 corners and along one of the edges after flattening and putting a secondary bevel on 5 brand new LN bench chisels. Seems I read about someone else having the same issue recently. I wonder if the 8000 grit stones are having an issue...I'm using my stones the same way as you do, for sharpening only. As Andrew mentioned, I have noticed my DMT lapping plate mellowing out a bit with use. I really like this system. I took the chisels to a joinery class last night and out of 6 stubents, mine were the only ones that passed the instructor's inspection. He did make a comment that by using LN chisels and their dovetail saw I now could not blame anything on the tools. His comments were prophetic...