DMT Diamond Sharpening Bench Stones Recommendation Request

[Jeff Wright]

I am assembling my sharpening tools. I plan to get both the 4000 and 8000 Norton stones, and since I have read disappointing reviews of the Norton coarse stones, I will instead get a DMT duo diamond sharpening bench stone to both flatten my Norton stones and the backs of my chisels and plane blades. There may be times I'd like to sharpen a shaper and/or router bit as well. I will get the 10" size diamond stone. I use the Veritas MK II Honing system.

What Duo DMT diamond stone would you recommend? They come in double-sided grits of:

extra fine/fine,
extra fine/coarse,
fine/course, or
coarse/extra course.

[Gary Benson]

I have the x-course/course (220/325) that I use to flatten before moving to 1000, 4000, 8000 Nortons. Seems to work well. Would not want to use anything slower for initial flattenting, especially of hardened chisels and irons.

[Jim W. White]

I also have the course/x-course, and would go with that again. I have the set of stones you are describing, as well, and it has worked out very well.

Jim in Idaho

[Brad Woods]

I had just puchased the 1000, 4000, and 8000 grit Norton stones when I read an article in Woodworking Magazine by Chris Schwartz. He talked about people sharpening more than needed and recommended the DMT course/x-course, Norton 1000 & 8000. General sharpening is done with the 1000 and then the 8000 grit stone, and other work, including stone flattening is done with the DMT. I bought a DMT and gave it a try. I'm sending my 4000 grit stone back. I have seen no need for the intermediate grit stone.

There are so many opinions and ways of sharpening that you'll rarely find people who agree. I think the set up Chris describes work well, and that is what I plan to use for the forseeable future. My $.02 worth.

Brad

[Jeff Wright]

I had just puchased the 1000, 4000, and 8000 grit Norton stones when I read an article in Woodworking Magazine by Chris Schwartz. He talked about people sharpening more than needed and recommended the DMT course/x-course, Norton 1000 & 8000. General sharpening is done with the 1000 and then the 8000 grit stone, and other work, including stone flattening is done with the DMT. I bought a DMT and gave it a try. I'm sending my 4000 grit stone back. I have seen no need for the intermediate grit stone.

There are so many opinions and ways of sharpening that you'll rarely find people who agree. I think the set up Chris describes work well, and that is what I plan to use for the forseeable future. My $.02 worth.

Brad

Good feedback Brad. It got me thinking.

I just went back to Ian Kirby's book Sharpening With Waterstones. He suggests a coarse stone [alternatively, I will use the coarse/extra coarse diamond stone], a medium stone of 4000 grit, and a fine 8000 grit stone. He says:

"If you choose a 1200-grit stone for sharpening, you'll cut the metal quite quickly, but you'll also leave relatively large scratches. This means correspondingly more time on the fine stone. On the other hand, if you use 4000-grit as your sharpening stone, you'll cut the blunted bevel back more slowly, but you will leave finer grooves on the metal, and spend less time polishing on the fine stone. Since the fine stone is both more expensive and more liable to be gouged, the less time you spend on it the longer it will last. And since the total time is the same either way, on balance you're better off with a 4000-grit sharpening stone [positioned between your coarse and fine stones]."

- Coyright 1998 Ian Kirby, Sharpening With Waterstones, Linden Publishing, ISBN 0-941936-76-7

As you said, expect as many different opinions as the number of people you ask. I still think I will try the diamond coarse/extra coarse, 4000, and 8000 stones. But then, what do I know?!:o

[Rob Blaustein]

I also read Chris's piece in Woodworking and as a novice it really helped simplify things for me. I'll probably get a DMT coarse/extra coarse stone--though they are a bit pricey ($95 on Amazon).

One of Chris's points, and this gets to the issue that Jeff's quote of Kirby addresses, is that you only need to use the 8000 stone when you initially flatten the face, and then only on the secondary bevel (he uses the coarse for the primary bevel). And for the secondary bevel, you only need a few passes since the amount of metal being polished is so small. So you end up not wearing out the fine stone as much. This is also the approach that Charlesworth advocates (which is where Chris learned it).

[Jeff Wright]

Brad or Rob . . .

Do you recall which issue of Woodworking Magazine that article of Chris' was in? Thanks.

[Caleb Dietrich]

Be careful to consider future purchases when you choose the Duostone you buy now. I bought the 10" Coarse/fine, only to find out later that they do not make an X-coarse/X-fine combination. You can really paint yourself into a corner. I called DMT and they said they can't make the xtra/xtra combo because there is too much difference between the two. If you are going to finish with waterstones, as I think you should, you might as well stay coarse with your DMTs. You'll find there is not much difference between the grits anyway. They are all coarse. I am, however, interested in the the new Extra Extra Fine stone DMT is coming out with. They claim its comparable to an 8000 grit waterstone.

[Eddie Darby]

I have the 1,000 , 4,000 and 8,000 Norton stones, and I got the DMT X-coarse and Coarse 10" x 4" stone for flattening the Norton stones. DMT recommend this X-Coarse diamond stone for flattening waterstones.

I forget what Norton stone it is, but one of them came with the edges sharp, the other two had the edges chamfered already. It was recommended by Rob Cosman of LN to chamfer these edges slightly, like the others, so that you avoid chipping them. I used the diamond stone to do this.

I also have the Fine, X-Fine stone for router bits and such. I see that they are producind a XX-Coarse diamond stone now. I didn't know about the XX-Fine one though, so I will have to check it out. Thanks for the info Caleb.

[Rob Blaustein]

Brad or Rob . . .

Do you recall which issue of Woodworking Magazine that article of Chris' was in? Thanks.

Autumn '04--I think their second issue. I really like that mag.
Rob

[Mike Brady]

I'll play the contrarian here and advise against the DMT stones for this purpose. I abandoned them long ago and here's why:

The purchase of a diamond stone for the sole purpose of flattening waterstones seems like expensive overkill. Besides that, diamond stones are notoriously un-flat, so they aren't necessarily suited for the job.

Invest in a $30.00 granite block and some sandpaper instead. The result is far superior, in my opinion and you can use the granite block for other sharpening as well. The all-important 8000 waterstone needs a smoother flat finish than that left by the x-course diamond stone. I use 400 grit wet sandpaper.

I believe that a DMT diamond stone will eventually be ruined in the process of flattening another abrasive stone of any kind. Many posters have reported this problem, and I have experienced it also.

Just one opinion, of course.

[Dean Lapinel]

I flatten my coarse waterstone on my concrete driveway. This works beautifully. Then I use that stone to flatten the 1000...the 1000 to flatten the 4000 then the 4000 to flatten the 8000.

The 4000 and 8000 don't need much work if my previous set up was good. The 8000 polishes the steel in just a few strokes.

[Rob Blaustein]

I'll play the contrarian here and advise against the DMT stones for this purpose. I abandoned them long ago and here's why:

The purchase of a diamond stone for the sole purpose of flattening waterstones seems like expensive overkill. Besides that, diamond stones are notoriously un-flat, so they aren't necessarily suited for the job.

Invest in a $30.00 granite block and some sandpaper instead. The result is far superior, in my opinion and you can use the granite block for other sharpening as well. The all-important 8000 waterstone needs a smoother flat finish than that left by the x-course diamond stone. I use 400 grit wet sandpaper.

I believe that a DMT diamond stone will eventually be ruined in the process of flattening another abrasive stone of any kind. Many posters have reported this problem, and I have experienced it also.

Just one opinion, of course.

Mike,
In the Schwarz article referred to above, the DMT stone is not used solely for truing the other stones. He recommends using it for the initial flattening of the face (x-coarse diamond, f/b coarse diamond, then 1000 waterstone, and finally either 6000 or 8000 waterstones), and for the primary bevel (coarse DMT). Then hone the secondary bevel on the fine stone.

What happens to the DMT in the course of flattening the other stones? Does it just wear out or change its shape? Just curious, since I'm thinking of getting one.
Rob

[Mike Henderson]

I've used my DMT stone for flattening my water stones for quite a while and the diamond stone is still good - that is, I can use it for flattening the back of a chisel or plane blade and it works well.

I understand that the DMT will eventually wear out - like any tool - but it does the job that I bought it for and does it well. When it finally wears out, I'll buy another one.

Mike

[Mike Brady]

If you look at the literature that accompanies DMT diamond hones, you will see that the diamond particles are bonded to the metal matrix with nickel. The colored dots are just a plastic bed. Nickel is going to surrender to the abrasive particles (of any size or grit) that are presented by a rubbing on a waterstone. Eventually, the nickel loses its grip on the diamonds and off they go down your drain. My point is why not have this process happen with an $1 sheet of sandpaper rather than your $90 diamond stone. Believe me, the likes of Chris Schwartz and David Charlesworth have my utmost respect for their expertise. I just don't quite get the economics of this recommendation. I'll tell you that my diamonds stones are pretty much shot after using them for things other than their intended purpose and are not being replaced.

Another theory that I don't buy is that you can flatten two waterstones by rubbing them together. It is a great way to arrive at a two perfectly mated parabolic surfaces.

Its quite simple really. If you want to flatten something like a waterstone, it needs to be rubbed on another perfectly flat and unyielding surface, with some form of abrasive in between. Granite reference blocks have become very affordable and readily available, and fill the bill. Not too portable, though.

Please correct me if I am overlooking something, and as always mine is just one opinion.

[Jeff Wright]

I'll tell you that my diamonds stones are pretty much shot after using them for things other than their intended purpose and are not being replaced.

So that is to say, if you use them FOR their intended purpose, they should provide satisfactory service, and perform as advertised? That's good enough for me.

[Rob Blaustein]

My point is why not have this process happen with an $1 sheet of sandpaper rather than your $90 diamond stone. Believe me, the likes of Chris Schwartz and David Charlesworth have my utmost respect for their expertise. I just don't quite get the economics of this recommendation. I'll tell you that my diamonds stones are pretty much shot after using them for things other than their intended purpose and are not being replaced.
I haven't yet tried either approach, but I thought that the tradeoff of using the expensive diamond stone vs the inexpensive sandpaper was one of convenience--no need to have the granite+sandpaper setup, replace the sandpaper every so often, etc. And I guess I also assumed the DMT stone would stay in good shape, certainly given the amount of use that a weekend hobbyist would subject it to (and I gather Schwarz would use it a lot more than I would).


Another theory that I don't buy is that you can flatten two waterstones by rubbing them together. It is a great way to arrive at a two perfectly mated parabolic surfaces.
See this thread (http://sawmillcreek.org/showthread.php?t=49223), mostly starting from post #13 for a long discussion of this point.

-Rob

[Randy Klein]

I believe that a DMT diamond stone will eventually be ruined in the process of flattening another abrasive stone of any kind. Many posters have reported this problem, and I have experienced it also.

Mike,

I agree with you on this. My DMT diamond stone was used for flattening my Norton stones. But now, my X-coarse side has lost its sharpness compared to the coarse side.

I first noticed this when my 8000 grit seemed to take forever to flatten and it seemed to be glazed over.

I gusee I'll switch to granite and sandpaper.

[Wiley Horne]

Hi All,

People are reporting very different experiences with diamond stones. I'll relate mine. I have bought 6 monocrystalline, single-sided, diamond plates so far. The first three were Nortons. It didn't take long using them for back-flattening and bevel-shaping, to feel the loss of cutting power. Eventually they just got bald, and now I use them as substrate for diamond paste (because they do have a flatness spec on them!) and they are excellent in that capacity. The second set of 3 plates were DMT DiaSharps (not Duo Sharps). Like the Nortons, they have also lost their bite more quickly than I would have expected. Eventually, and maybe not too long from now, they'll be substrates for diamond paste also. I like diamond paste quite a lot, but not fixed diamond.

I totally agree with Mike Brady about using granite surface plates. One of the best buys you'll ever make. And for a range of duties in the shop. Including heavy duty back-flattening and bevel-shaping--I use 80-micron (approx. 200g) abrasive PSA film for this. They're good for bevel shaping on gouges too, if you happen to like long flat bevels on gouges. They're also excellent for truing cabinet doors for flatness (Dave Anderson got me onto this use). Granite plates are also the very thing for truing plane soles. The Made in China Grade B black plate I bought came with the lab report and flatness test printout packed in the box with it.

Wiley

[Mike Henderson]

My point is why not have this process happen with an $1 sheet of sandpaper rather than your $90 diamond stone. Believe me, the likes of Chris Schwartz and David Charlesworth have my utmost respect for their expertise. I just don't quite get the economics of this recommendation.
Please correct me if I am overlooking something, and as always mine is just one opinion.
If you're using $1 sheets of sandpaper, the diamond stone should work out fairly well from a financial point of view. I've been using a DMT diamond plate for a variety of things, including flattening my water stones. I use it when I want to remove a bunch of metal (like if I nicked the blade or want to change the bevel angle), to flatten the back of a chisel or plane blade - and to flatten my water stones.

I've been using the diamond plates like that for more than a year (maybe two - time flies) and haven't noticed any significant loss of cutting ability. I'm sure I've flattened my water stones a lot more than 90 times in that period (clarification - 90 waterstone faces).

Previous to the DMT stones, I used a piece of thick glass and 'wet-or-dry' sandpaper. The advantages, to me, of the DMT stones are that they're easier to carry (less "stuff"), they last a long time, and the work well (they're flat and they stay flat).

Even if the DMT stones were a bit more expensive than sandpaper, I'd still use them.

As to their wearing out (eventually) - all tools wear out if used. I figure that when my DMT stones stop cutting I'll buy a replacement and consider it the cost of sharpening.

I don't ever want to go back to sandpaper on glass (or granite).

Mike

[Jim Nardi]

Evening All,

DMT duosharp stones wear out to fast for my liking. You can really kill them quick flattening the backs of A2 irons. I'm not sure why but flattening Norton and King stones killed mine quickly. Router bit's are easier to sharpen with a 600 grit pocket DMT hone. Some Router bit's are sharpened to 400 and others to 600 grit. The granite stone is such a usefull tool and you can buy sandpaper in bulk cheap. Cloth backed 100 Grit is my favourite for flattening stones. I still think you need a 1000,4000 and 8000 stones for flattening irons and chisels. How do you flatten out 1000 grit marks with a 8000 stone on a plane iron? I personally follow the David Charlesworth method and reccomend it to anyone for bevel down planes. Bevel up I sharpen "normally" if there is such a thing. Shiny isn't sharp so buying a jewlers loop or magnifing glass will speed you along. A basic cheap 6" grinder will with some practice and a decent rest make short work of big metal removal. Good luck hopefully it will save you a few bucks to spend on tools.

[Eddie Darby]

Bevel up I sharpen "normally" if there is such a thing.

The problem with bevel up planes is that the blade will wear on both sides of the bevel, and the flat side/back is next to the wood, so it gets a real beating. I think you will find that doing the "Ruler Trick" will help you with BU sharpening as well.

[Derek Cohen]

I am presently using Shapton ceramic waterstones in 1000, 5000 and 8000 grits. These do flatten on 220 grit sandpaper (on a glass substrate), but I wanted a more reliable, convenient and compact system.

The choice was either the cast iron flattening plate (using diamond dust) from Shapton, or a diamond stone, such as an Extra Coarse DMT. The Shapton system is expensive, expecially to ship one to Oz, and I did not fancy the use of diamond dust (either to store it or the issues of contamination). Still, this system gets a lot of praise from owners. If I was more adventurous ....

I spoke with a number of serious Shapton users, such as Steve Knight (who must really be considered a Serious Tester). The considered opinion was that a diamond plate was the best way to go. There is a previsor ...

Steve warns that diamond stones are poorly suited to long term use on steel. They wear quickly (not the initial "breaking in" period, which is what most people associate with the diamond stone wearing out). However, when used solely on waterstones, they will last a very (!) long time. They do not break down.

So I bought the largest (10 or 11" long) DMT Duosharp in Coarse/Extra Coarse, and this is what I use. It is convenient to store (small footprint), easy to clean (run it under a tap/faucet), is flat (warrented), and works very quickly.

Regards from Perth

Derek

[David Martino]

Where do you get a granite reference plate?

2nd dumb question:

If I'm using a plate with sandpaper, what grits are equivalent to a coarse diamond stone (say 220) or a coarse grinding wheel (like 60)?

[Mike K Wenzloff]

Where do you get a granite reference plate?
Woodcraft, Grizzly

2nd dumb question:

If I'm using a plate with sandpaper, what grits are equivalent to a coarse diamond stone (say 220) or a coarse grinding wheel (like 60)?
http://users.ameritech.net/knives/grits.htm

Take care, Mike

[Maurice Metzger]

If you do get the DMT diamond stone(s), make sure you check for flatness right away after opening the box. I returned one for that reason, and other have had the same problem.

Maurice

[David Martino]

Mike W.,

Thanks for the chart - very handy. Grits seem simple till you take a closer look.