Is my diamond plate okay?

[Robert Bernard]

263872
Flattenned one stone on my brand new 4X10 course dia-sharp and now there is a dull spot in the very middle of it. Is this normal? Or should I return it?

Oh yeah, this is my first post. New to woodworking. Just learning the basics.

[Ryan Baker]

The dulling is normal. The fact that you have one little spot in the middle makes me wonder whether your stone and/or your plate are flat (check them and see). As long as it is flat and still cuts you are fine.

[David Weaver]

How coarse in the stone that you flattened? I sent one of those to stu last year, I wonder if he's killed it with coarse stones yet.

[Robert Bernard]

Hmm. It's a new shapton pro 320 that had a definite bulge in the middle.

[David Weaver]

That'll probably dull the nickel plate (or whatever they use) a little on it like that, there's nothing wrong with it. The warranty on them is lifetime, anyway, isn't it?

[Winton Applegate]

Welp
here's one way to tell if your diamond plate is OK (you mean flat right ?):
Find a certified flat surface plate. Or buy yourself one as I did. OK, I'm a tool turkey. I admit it. Honestly though I don't understand how people make it through life without a surface plate and a metal lathe. Survival tools; the modern equivalent of the Swiss Army Knife if you ask me.
anyway
Put a high quality straight edge on the surface plate and check to verify the straight edge is straight. (shine a light behind it and look for gaps etc.)
If straight use it to check your diamond plate. Don't slide the straight edge around, obviously, just check it diagonally both ways, longitudinally , cross ways. every which way. Again sighting with light behind the straight edge. You could use a .0015 " feeler gauge but the light gap will be much less and so be even more accurate.


For wind you could turn the diamond plate upside down on the surface plate and press the corners to check for teeter. All the while keeping your rear end puckered and not drop the diamond plate on the surface plate and not slide it around ( again obviously ).


I have a couple of diamond plates like you show but for flattening stones I use this style http://www.amazon.com/DMT-W250CXNB-10-Inch-DuoSharp-Extra-Coarse/dp/B00004WFUL/ref=sr_1_11?ie=UTF8&qid=1370488832&sr=8-11&keywords=dmt+diamond+sharpening+stone
The round punched out areas give the loose grit some place to go and so makes a better stone flattener.
I have one of these as well
http://www.japanwoodworker.com/product/140562/100-grit-Ceramic-Stone-for-Flattening-Water-Stones.aspx
and had to use the diamond plate to FLATEN it before I could get flat stones.
In short
don't trust anything, verify everything and
hope that certification certificates still mean something.
Some people have said I am certifiable. I am not sure I deserve such high praise but I appreciate them saying so.

[Stuart Tierney]

That'll probably dull the nickel plate (or whatever they use) a little on it like that, there's nothing wrong with it. The warranty on them is lifetime, anyway, isn't it?

Is it?

Really?

Awesome...

I've been holding off completely killing it because I still need it for testing and whatnot, but as it's not working 'like new' any more, might be time to give it the bullet.

But how to do it? I'm open to suggestions!

Stu.

(Sorry to tell you I'm going to kill it Dave. I've been real gentle with it until now though. I promise. REEEEAL gentle...)

[Jim Matthews]

What grit is the plate shown?

I'm wondering if the wear areas are the shiny parts, around the dark center.
Most of my stones wore down more quickly in the middle.

When flattening them, the diamond stone would come into contact with the periphery first and longest.

I'm just using the diamonds now, so I can't verify this.

I think what you're seeing is a "pond" of slurry that isn't pushed off during flattening of the stones.

[David Weaver]

Is it?

Really?

Awesome...

I've been holding off completely killing it because I still need it for testing and whatnot, but as it's not working 'like new' any more, might be time to give it the bullet.

But how to do it? I'm open to suggestions!

Stu.

(Sorry to tell you I'm going to kill it Dave. I've been real gentle with it until now though. I promise. REEEEAL gentle...)

You can belt sand the surface of it if you'd like. It's yours now :)

Might not be a bad thing for you to keep around to grind those HAP chisels, but they should never need anything that coarse.

[Charlie Stanford]

The dulling is normal. The fact that you have one little spot in the middle makes me wonder whether your stone and/or your plate are flat (check them and see). As long as it is flat and still cuts you are fine.

So the plate used to keep the stone flat is out of flat itself so we may need another plate to flatten the plate that flattens the stone? Or is a belt sander needed to flatten the plate that flattens the stone? Or is the stone we're supposed to be flattening making the flattening plate out of flat?

[David Weaver]

The dulling is normal. The fact that you have one little spot in the middle makes me wonder whether your stone and/or your plate are flat (check them and see). As long as it is flat and still cuts you are fine.

They are dead flat and they are individually checked certified flat (as opposed to just having a spec). The dull spot in the middle is there because of a swarf accumulation (as in, the grit wasn't able to get away from the process). It is from the same effect that you would have if you tried to saw a log with a saw that wasn't long enough to get through the log on every stroke.

[Chris Griggs]

So the plate used to keep the stone flat is out of flat itself so we may need another plate to flatten the plate that flattens the stone? Or is a belt sander needed to flatten the plate that flattens the stone? Or is the stone we're supposed to be flattening making the flattening plate out of flat?





Nice of you to edit the part out where you called the new posters/new woodworkers situation asinine.

How about you contribute something productive to my what's on your bench besides sharpening stones (http://www.sawmillcreek.org/showthread.php?203639-The-whats-on-your-bench-besides-sharpening-stones-thread&highlight=) thread instead of bringing other people down?

[David Weaver]

So the plate used to keep the stone flat is out of flat itself so we may need another plate to flatten the plate that flattens the stone? Or is a belt sander needed to flatten the plate that flattens the stone? Or is the stone we're supposed to be flattening making the flattening plate out of flat?


Zero of these are true. But you knew that before you posted.

[Charlie Stanford]

Zero of these are true. But you knew that before you posted.

Sumpn's out of flat. Is it the diamond plate, the stone, or a little of both? Only one's hairdresser knows for sure.

Clearly, what this fellow needs is a $200 machinist's straightedge or maybe a granite surface plate to figure out which is the offending party.

[David Weaver]

Sumpn's out of flat.

You would conclude that only if you didn't know what's going on when you lap a stone and trap loose grit under it.

[Charlie Stanford]

Which loose grit is being trapped - the stone's or the diamond plate's?

What exactly is your recommendation again?

[David Weaver]

The stone's. Recommendation is to use the diamond plate as it is. When you use tools, they wear.

[Mike Brady]

Is your new diamond plate a Dia-Sharp as stated or the special-for-flattening Dia-Flat?

[David Weaver]

Good point, Mike. I think we've been assuming that it's a dia flat, but it doesn't look like the edges are rounded as they are on a diaflat.

[Mike Brady]

I don't think that the Dia-Sharp is guaranteed, so its an important distinction. I'm not a sharpening maven, but I have seen mention of folks using the Dia-Flat for both flattening and sharpening to take advantage of the "revolutionary anti-wear treatment" it receives in manufacturing. I flatten my stones with a Dia-Sharp, but its one of the long ones (11x3?). It does a nice job on both natural and synthetic stones.

Also, someone up above mentioned the plates with the dots....I don't think that feature does anything but cut down on the amount of surface area that contains diamonds. The dots themselves serve no functional purpose.

[David Weaver]

I think DMT claimed that the interrupted surface on the dotted plates gave swarf somewhere to go. If you looked at them, however, they were at the same level as the rest of the diamond matrix after some use, if not initially.

I'm not sure exactly what the change is on the diaflat in terms of the coating, but I looked briefly at the one I zipped off to stu, and it looked by inspection like it was a thicker electroplate. Whether anything else special is done on it, I don't know. Out of manners, I didn't use it since it was ammunition in a years-long trade war I have going with Stu. It was an interesting piece of gear, though looks and feel of it left me wondering where the $175 price tag comes from. It would be a nice item at a single c-note.

[Steve Friedman]

I think DMT claims that the Duo-Sharp (the one with the holes) is flatter than the Dia-Sharp. Not sure if it's true, but DMT does guarantee the flatness of all their plates. Excerpts from the DMT Website:



All DMT® products are made using the highest quality materials and workmanship and are guaranteed to be free of defects. Any product found to be defective, will be replaced free of charge – it’s that simple!

When used properly, kept clean and stored dry, DMT® diamond sharpeners will last a very long time. They do not last forever, but they last for years and years. If you use your sharpener as part of your daily work and use it many times a day, you will likely need to replace it in a few years after extraordinary service.

DMT® sharpeners are very, very flat. The DuoSharp® models are engineered to be precision flat – incomparable to any other sharpening stone on the market today. However, if you are concerned that your sharpener is not flat enough for your application, send it back to us for evaluation. Please send it to

DMT® Customer Service
85 Hayes Memorial Drive
Marlborough, MA 01752

To maintain your sharpener, you should clean after each use with water and wipe dry. After several sharpenings, use a mild kitchen abrasive cleanser and a nylon scrub brush.

If you have not cleaned your sharpener on a regular basis, it could be full of metal fines (swarf buildup) which is clogging the stone surface and affecting its performance. If you are concerned that the diamond may have worn off the stone, rub the sharpener against an old glass jar. If the sharpener scratches or frosts the glass, then there is diamond on the sharpener ready for your sharpening needs.

The DMT Dia-Flat™ Lapping Plate.
It utilizes 120 micron / 120 Mesh size diamond to quickly flatten any grade of waterstone or any other type of sharpening stone. Use of our newly developed proprietary DMT® Diamond Hardcoat Technology™ allows the Dia-Flat™ to withstand the extreme service conditions incurred when flattening other abrasive sharpening stones.

Some DMT Diamond Sharpeners could be used (and have been used) for flattening, however, they were designed for sharpening, not flattening, therefore, DMT assumes no liability for sharpening stones worn out due to this method of use.



I've become an Atoma convert, but the DMTs should work as well. Not sure what DMT's typical response is when a plate is returned to them.

Steve

[Mike Holbrook]

I bought a DMT Dia-Flat recently as I read that the guys at LN were raving about them at wood shows etc. and I wanted something very flat to flatten....The box on my Dia-Flat says Hand-certified flat to +or- 0.0005". I picked one up at Highland Hardware's annual 20% off on one non power tool sale.

David, DMT says the Dia-Flat has over 30 carats of diamond and claims their "Hardcoat Technology" last longer than any other diamond lapping plate. Mine measures 10" long x 4" wide x -3/8" thick. As you know it is very heavy.

oops someone beat me to the punch on some of those stats!

[David Weaver]

The duos are always flat. It's probably easier to make super dead flat plastic cheaply than it is to make metal inexpensive.

What I've seen of diamond hones, though, when they're out of flat it is a lot more gradual than the OP showed. Loose swarf will always abrade the middle of a plate the fastest.

I wonder when the part about not replacing hones due to (presumably stone) flattening was added. I never noticed it, but I blew out a duosharp using it only for metal and didn't send it back to them as I got my money's worth out of it, so I don't have any familiarity with their warranty.

(I am also a fan of the atomas, they make the most money sense if longevity is a concern)

[Sam Takeuchi]

'Dia-Sharp" plates are not flat and they are quite random in its unevenness. I bought 3 plates in my early days and all of them were varying degree of unflatness. They guarantee within manufacturing tolerance, if I remember right, written in some paper that came with the plates and it was generous tolerance. And besides, Dia-Sharps didn't last that long and I have never ever missed them. Now I have a stropping leather glued onto the plate. At least for that, it's a good chunk of steel plate, albeit stupidly overpriced.

[David Weaver]

I believe the tolerance was 5 thousandths of an inch. The tolerance is less for the diaflat plate, but the price reflects it.

The ezelap diamond laps make a lot more money sense than the diasharps and duosharps, but I don't know how flat they are. If I had a blown out diasharp, I would use it as a base for cheap loose diamonds.

The atomas are always flat.

[Robert Bernard]

Wow. All this discussion for what I thought was a mundane question.

I checked the dia-sharp with the edge of a precision scale and its close enough to flat to make me happy. I'm not designing space shuttles I'm working wood.

I like the answer that swarf trapped in the middle may have worn the nickel playing faster as I was flattening the shapton. Also the shapton was high in the middle (brand new stone).

Thanks for the help!

[Charlie Stanford]

Wow. All this discussion for what I thought was a mundane question.

I checked the dia-sharp with the edge of a precision scale and its close enough to flat to make me happy. I'm not designing space shuttles I'm working wood.

I like the answer that swarf trapped in the middle may have worn the nickel playing faster as I was flattening the shapton. Also the shapton was high in the middle (brand new stone).

Thanks for the help!

Here's how the manufacturer/distributor says to flatten, for point of reference if nothing else. Looks thorough enough to me. Did you do it just like they said, with the reference plates they recommend? It appears to me the fine folks at Shapton have everything covered. I wouldn't deviate one iota were I lucky enough to own some of their stones.

http://hmsenterprises.com/webstore/hmsincludes/pages/shappages/maintenance.php

Or maybe you weren't trying to flatten Shaptons. Thought I saw the name mentioned in a post.

[David Weaver]

There is no reason to buy shaptons overpriced reference lap. It also has a finite life. .

[Charlie Stanford]

There is no reason to buy shaptons overpriced reference lap. It also has a finite life. Perhaps, charlie, you could refrain from providing advice until or unless you have actual experience.

I think following the manufacturer's instructions for maintaining their product is always good advice.

[David Weaver]

Robert, from the rest of us, the reality is with any of the coarse stones that they will eventually get after the electroplate on any of the diamond hones. The finer stones don't so much do it.

The shapton (and everything) favorite for a reasonable price is the atoma (buy it from japan if you ever do get the itch, that's where it's cheapest), but that doesn't mean that you have any reason not to use the diasharp or for that matter any reason to buy an atoma. If a shapton 320 eats a diasharp (in my experience, the 220 is very hard on pretty much any diamond plate), then it will also eat other plates (because of the coarse and aggressive abrasive).

If you do come to the conclusion that the plate is losing its plating too fast, you can switch over to loose abrasive (shaptons rip apart sandpaper) for the coarse stones (like below 700 grit ratings) and save the diasharp for the finer stones.

Shaptons lapping plates are no exception to eventually getting clapped out, unfortunately. The price in them appears to be for the flatness spec..and the brand name.

Cheap silicon carbide loose grit is fine if you end up going that route to keep the shapton 320 flat and its surface fresh and fast cutting.

[Winton Applegate]

It's nice to see the straight edge I use is still affordable. Pretty darn accurate but was able to improve it a skoch.
http://www.amazon.com/Steel-Rule-Rigid-0-5-1mm/dp/B000VB73QC/ref=sr_1_1?ie=UTF8&qid=1370571226&sr=8-1&keywords=mitutoyo+12%22+straight+edge
That is what I enjoy about this forum though. People, most , here appreciate taking things one step at a time and doing things right in a methodical manner to produce the highest level of craftsmanship (craftspersonship).
and
then there are a few clowns to keep things lively and off balance.
With any luck I will fill both shoes from time to time. The Allen Edmands shop trekkers as well as the big floppy red whoopsy doodles.
Stay tuned.

[Winton Applegate]

Mike,
My name is Winton. Nice to talk with you.

"Dots" are lack of diamond
I agree you kind of get gipped out of as many diamonds but the "dots" are HOLES and the swarf goes down them and so does not build up and float the stone, or blade back/what have you, above the cutting surface. Why do I think this ? Were did I get this outlandish idea ? Well first and foremost using both styles of diamond plates. Second see the stone flatteneing stone; it has the groves in it to serve the same function.

One last reason I see for the holes is that since there are less cutting diamond points per square inch there is more force on each point and so they have a better chance to cut rather than skate. When attempting to sharpen a narrow chisel etc. this is kind of a negative but with a large blade or stone etc it can be a positive effect.
Details brutha
God is in the details.

[Winton Applegate]

I think DMT claimed that the interrupted surface on the dotted plates gave swarf somewhere to go. If you looked at them, however, they were at the same level as the rest of the diamond matrix after some use, if not initially.

I'm starting to see where the "Religion" thing comes in.
I must have got the only good one. Holes still holy.
: )
I rinse it under a running facet periodically while I use it. As I do all my stones. So the pores stay as open as possible. I'm not a big slurry builder kind of sharpener. Cleanliness is next to (Ok I'll stop).
Not warm, not cold, but just right so as not to shock the stones.
There's that "prissiness" sneaking in there. Did you all see it fly by ? It's lurking over there in the corner. God help us if it decides to move against us.


Pardon the toooo many photos. I was changing angle; hopefully one or another turns out on your end. Obviously I haven't visited the Camera forum here. Is there one ? I could benefit from the experience for sure.263917263918263919263920

[Winton Applegate]

. I'm not designing space shuttles I'm working wood.

As I said to a new "apprentice"
( he cuts up boxes and cleans up etc.)
He was assigned to fix the lock/hasp on the dumpster gate.
He broke a lag bolt off in the wood trying to thread it in.
I said "Hey, woodworking isn't rocket science".
and he started to look pissed and hurt
then I said "It's harder".
and he seemed think that was OK then.

[Winton Applegate]

Ferrari . . . how to take care of them.
Funny thing, they run better with the NGK (Japanese) plugs than the Bosch (Euro) plugs

[Jim Matthews]

God is in the details.

See what I mean?

I remember one of the big dogs, early in the early days of video on the Internets saying,
"Carpenter's don't get paid to sharpen."

[David Weaver]

That one looks pretty good, Winton! Wish mine looked like that.

[George Beck]

One thing you might consider. If I have a stone that is visibly cupped or dished, I use an old worn dia flat or a coarser stone to remove the high spots and get the stone reasonably flat. Then I will go to my "Known to be true" Lapping plate. I use Atoma plates. I also use two plates, one for coarse stones and one for finer stones.

George

[Steve Friedman]

One thing you might consider. If I have a stone that is visibly cupped or dished, I use an old worn dia flat or a coarser stone to remove the high spots and get the stone reasonably flat. Then I will go to my "Known to be true" Lapping plate. I use Atoma plates. I also use two plates, one for coarse stones and one for finer stones.

George
Now that's a great idea. I am always worried about wearing out the Atoma plates and never thought of using older DMTs to do the dirty work.

What grit Atoma do you use for each stone? I use an Atoma #140 for my Cerax 320 and Sigma 400. I use the Atoma #400 for everything else. Do you a higher grit Atoma plate for the super high grit stones?

Steve

[George Beck]

Steve

I use Atoma 140 plate for stones coarser than 800. I use a 400 for about everything else. I do use a 1200 Atoma for really fine stones (15,000 and up) and follow on the fine stones with a very hard, black nagura stone. I also use the 1200 for some backs. I should mention that these days I really don't need to flatten stones very much. I just keep them flat. I use the lapping plates mostly to bring up fresh abrasive. I can't remember that last time I used the 140 but then I don't use my coarse stones very much anymore. I used to use them all the time. I even went all the down to nothing on a 320 stone. But that was back when I didn't really know what I was doing. Nowadays, if I can't raise a burr with a 1000 grit stone, I am heading back to the grinder for put a new hollow ground edge. My current sharpening method is hollow grind and then about 10-12 stokes on a 2000 grit Shapton or 1200 sigma and then 10 stokes on a 5000 and finish on a 15000. My Japanese tools are different and I only use a flat bevel but Japanese tools are easier to sharpen, in my opinion, because most of the material behind the edge is soft.

George

[Tony Shea]

So Robert, did we decide whether this is the dia-flat lapping plate, the new 120micron waterstone shredder? Or is it a dia-sharp diamond stone? I assume it to be the latter given your original coarse description of the stone. I think DMT's 120 micron rating is actually considered to be XX coarse. Which IMO is a bit much for some of the fine 8000grit+ stones. It must leave some serious scratches behind on your expensive finishing stones, which probably doesn't actually effect your final edge but just looks terrible. I used to think that my Xcoarse DMT duo was too coarse but it really has settled down over the years and leaves a very nice finish.

Having said all that, I would almost recommend using a different method to flatten your real coarse (400grit and below) stones as I have experienced some very quick wear on a Xcoarse DMT after using it a few times on my 400 Chosera stone. Before using it on the CHosera my DMT was still very aggressive on 1000+ grit stones. I ended up switching to loose grit for the Cho and the dmt for the others. Supposedly this is the selling point of the Dia-flat lapping plate and will even flatten oil stones without seeing too much wear. I can't comment on how true this really is but I sure could use something to help get some oil stones I've picked up along the way into good working order without tearing apart my DMT duo.

Might be rambling a bit now and may or may not make sense. I have been up for a long time (28hr stretch at work for a big lighting control change over) so I'm a bit dazed.

[Mike Brady]

W. Applegate: dots are dots, not holes. As you can see from my surface gauge, there is a scant .001 difference between the surface if the diamonds and the plastic substrate (dots) to which the diamond plate is attached. You may choose to think that the dots are some ingenious method of removing swarf from the lapping equation (and why would you want to do that?), but they really are there to save that many diamonds to be used on the next product that DMT sells. It is well known before this discussion that DMT plates of this construction are often grossly out of flat. So tell me again what those non existent holes are for?http://i234.photobucket.com/albums/ee300/finefettle/IMG_0941_zpsa631140a.jpg (http://s234.photobucket.com/user/finefettle/media/IMG_0941_zpsa631140a.jpg.html)http://i234.photobucket.com/albums/ee300/finefettle/IMG_0940_zpsac2bda3f.jpg (http://s234.photobucket.com/user/finefettle/media/IMG_0940_zpsac2bda3f.jpg.html)

[george wilson]

The dots may be a method of helping the metal plates bond better to the plastic substrates. I never considered these DMT's to be particularly flat. They had a big one in the millwork shop that wasn't very flat. Construction was too weak.

I have one of the solid steel plate diamond stones. The first one I bought was not very flat. They look hurriedly milled or Blanchard ground. I took it back and brought a steel rule along. It is trouble to check those steel plates for flatness because they are wrapped in plastic,and when you get the plastic OFF,the ruler is held off of the surface by the diamonds. You can see plenty of light under the steel rule. I finally got a reasonably flat one,after spending time carefully examining several.

[Jim Neeley]

W. Applegate: dots are dots, not holes. As you can see from my surface gauge, there is a scant .001 difference between the surface if the diamonds and the plastic substrate (dots) to which the diamond plate is attached. You may choose to think that the dots are some ingenious method of removing swarf from the lapping equation (and why would you want to do that?), but they really are there to save that many diamonds to be used on the next product that DMT sells. It is well known before this discussion that DMT plates of this construction are often grossly out of flat. So tell me again what those non existent holes are for?

Mike,

This is the "Myth Buster" in me speaking; I'm neither here nor there on the flatness of the DMT plate nor the value of the holes / dots. I will share what the "Myth Buster" in me sees.

A .001 hole/dot would equal 25.4 microns. My 1000 grit Shapton's grit size started out with a nominal diameter of 14.7 microns and my 16000 is 0.92 microns.

Thus it would appear that my stone's grit could accumulate in that dot with the grit surface below the surface of the diamond. The holes are much larger in diameter than they are deep so many particles could fit in each dot. Now, that's only one data point (dot) and its unlikely that they're all exactly the same. Whether the one you measured is extra shallow or extra deep we cannot tell from the post. A large sampling of dots and stones would be required to develop a profile.

I'm not saying that those who claim the dots / holes are or are not swarf holders are correct but we must be careful as to the conclusions we reach based upon one data point that actually shows its swarf-holding function as plausible.

Jim

[Mike Brady]

Believe what you want to believe. You may not believe that flatness is desirable. You may not believe that the nickel substrate to which the diamonds are attached to the steel plate can be abraded away by any grit of stone that you may be seeking to flatten and your "holes" will be filled with loose diamond particles along with stone swarf. You may not believe in global warming. Your choice. Peace out.

[Robert Bernard]

It's a Dia-sharp stone. According to the words written on LV the dia-sharp is flat to +-.001" while the duo with the "holes" is flat to +-.003".

But you have to understand that flatness of that small of a number is not a big deal. That is an average of the entire surface. Most surfaces with that type of flatness are random hills an valleys, not consistent. If you are moving a stone around on the entire surface in figure 8's the hills and valleys tend to cancel out.

I may be new to woodworking but I've been a mechanical engineer for a long time. The amount of precision needed to sharpen a blade to function nicely in my shop does not require an expensive super flat surface. I've been winging it with my waterstones and a leather strop and I'm getting perfect shavings.

I am going to take some advice from this forum though and switch to silicon carbide powder for my 320. I think that stone may actually damage the substrate on the dia-sharp.

[Frederick Skelly]

+1 Jim. Your points look plausible to me.

In fact, i see a number of valid points throughout this thread. Check my thinking. Do the dots gather up SOME of the swarf? They seem to on mine. Do they gather ALL of it? Definitely not on mine. Do the dots let DMT use less diamonds? Seems possible, depending on the cost of metal. Heres how i got there. See what you make of it.

Diasharp 8x3", 220 grit is $70 at woodcraft. The diasharp in 325 grit is also $70. Thats 48 square inches of surface for $140, which works out to $2.92 per square inch.

Duosharp 8 x 2 5/8", with 220 grit on one side and 325 on the other is $100. Thats 42 square inches for $100, which works out to $2.38 per square inch.

I cant estimate the difference in manufacturing and material for the all metal diasharp plate versus the mostly plastic duosharp, and thats obviously part of the cost difference per square inch here. And I havent priced diamonds of the grade used on stones like this. But I wouldnt expect them to be terribly cheap, so thats got to be another part of the savings, doesnt it? So it seems plausible that using the dots ALSO saves them money.

Fred

[David Barnett]

...I was told that the perforations provided an easier, superior and more cost effective way of bonding a thin diamond-bearing plate to a resin substrate, offered a height more in line with traditional bench stones, allowed the substrate to help with flatness, minimized the less than consistent appearance of some diamond plates, allowed the tool being sharpened to move easily across the stone more resembling Arkansas and Western man-made stones, and last but hardly least, was a big hit with marketing as thicker stones suggest enhanced value and the look of the perforations and colored substrate was, at that time, considered especially attractive, high-tech and easier to see and differentiate from other bench stones, offering proprietary design distinctions and legal protections, so George Wilson was right on at least two issues.


The dots may be a method of helping the metal plates bond better to the plastic substrates. I never considered these DMT's to be particularly flat.

I have always preferred Eze-Lap for flatness, diamond quality and density, sharpening action, scratch pattern, durability and cost.

[David Weaver]

Whatever brand you like, avoid woodworking retailers. There is an enormous difference in cost vs amazon and eBay. The only exception I know of is the atoms at tools from Japan, which is probably cheapest there.

(I agree with David B. about the ez lap plates and they're less expensive than dmt, too.)

[george wilson]

I have bought my 3 plastic/metal stones( coarse thru fine) at gun shows for $25.00 each,and not off brands either. I bought my solid steel one at Woodcraft,though. It was a long time ago,before I started using a computer.

[Chris Griggs]

How well do the eze-laps work for flattening? I know folks like them the best for actual honing, but do they make decent flattening stones as well?

[Winton Applegate]

, "Carpenter's don't get paid to sharpen."

Well first off you/he are entirely right about that.
but
as Pee Wee nearly said "But, BUT, everybody has a but; lets talk about my big but."
My biggest but is this is a hand tool forum and almost by definition means we are not here to discuss the latest high production technology. I'm here to discuss and learn about the Acme, the puh, puh, PINNACLE
(sorry; as soon as I typed "Acme" i started channeling Daffy Duck) ( hey, it happens)
The veritable tippy top of cutting wood into fascinating, beautiful, breathtakingly value estimated for insurance purposes pieces of furniture and
let us not forget fun.
but , there's that word again, maybe you are talking about "carpentry", your word, and I am talking about fine "cabinet making".


Any way, as a wise man once said "there is more to life than increasing it's speed". Also one thing I see in some of the recent videos etc., is the person leading it either consciously or unconsciously has come up with one or two slogans that sound good and sound "common senseish" and hand those suckers out like business cards to create an "in the know" and "in the club" following.
Sometimes, sometimes, once in a great while, if a guy (or gal) follows that thread through the whole cloth they, sometimes, sometimes, once in a great while find that great short cut or "technique" is just words and promises and if one wants to harvest in the autumn one has to plant and tend the crops and do the long hard row hoe.
sometimes

[Winton Applegate]

dots are dots

Is that a coarse (blue dot) and extra coarse (black dot) diamond plate you have ? Looks kind of shiny like it is finer grit.

I once worked with an army ranger. He had many highly descriptive and colorful ways of putting things. Many of which I can not or should not repeat here. One of my favorites was " yah don't know do yah ? "

Oh boy
Ok
Gonna whip out some repeatable measurements and facts and stuff.
careful

Hey will somebody keep score ? Meaning let me know if I got my head up theee old pooper.

ONE THING TO KEEP IN MIND while measuring your way. Well several things actually :
The tip on your gauge must be smaller than the hole size or it spans the rim and cannot travel to the bottom of the hole. Note the black tip I tried to start with and the smaller silver colored ball end tip I changed to. In my case there was enough dome to the black tip to be nearly the same out come.

Did you wipe all the surfaces down that you were using with your bare palm ? It is remarkable how the smallest debris can be detected and removed this way. Otherwise this flotsam and jetsam can throw off your "precision" instruments. Speaking of which are you running the stone along your table saw fence or router table or sumpin ? Or the dial indicator along your miter slot in the table ? or are we depending on that wood and plastic structure for our measurement to ten thousandths of an inch repeatability and consistency ?

Are you sure you have thought this out ?

Looks kind of flexy/rattly/lumpy/dusty/wumpy
Is that an earth quake or are you shaking the video camera ? Meaning if your diamond plate is moving around on one iffy support and the gag, sorry, gauge is rocking around on the other iffy structure they gonna be doubling and canceling each other out and consistency well it's not looking good.

How accurate is that gauge ? Does that say Master Gag ?
Ha, ha, ha
OK lets say it says gage. Still doesn't inspire confidence.
Hard to see the tip shape. It is probably pointy enough to fit into the holes.

One Micron = .00003937 Inch
One /one thousandth of an inch ( .001inch ) = ~ 25.4 microns

The 220 grit size of the extra coarse (black dot side) of the diamond plate is ~ 60 microns

60 microns = .0023622 inch

The average depth of the holes from the top of the diamond to the plastic base was about .0025 inch (most were well over .003 up to .0035 inch.

Are you with me ?

Lets say the diamond cuts a swarf as deep as its diameter that's .00236. Well that will fit in the .0025 hole. Won't it ?

But there is the thickness of metallic plating holding the diamond to the perforated metal layer so the swarf isn't going to be the full 60 microns so less than .002 more than likely. Right ?
There is , obviously some diamond thickness gone now that the plate has been used and abused (out of frustration with the slow cutting progress on the A2 blade backs I probably had half my body weight on it at times. I had the sucker down on the floor and was pressing hard . That is abuse by the manufacture's standards).

So we must conclude the swarf, be it metal from a blade or grit coming off the stone being flattened, has to be less than the .003 inch depth of the holes.

By about the amount of your measurement error. I mean by about the amount of your results.
The swarf is bound to round (sorry) and get a bit smaller with the further movement of the work over the plate.

Now on a plate the same grit but no holes isn't the swarf going to just pile up until the work is, for the most part, sliding around on the swarf ? At that point the diamond is no longer cutting into the work in a significant way and the "operator" is getting exercise but not much flattening done.

But with holes it is going to take longer to get to that point. The holes have to fill up first. There is also the fewer points so more force per point thing I mentioned in the last volley.

One last observation. I flipped the diamond plate over and measured the hole depth in many places on the blue dot side. That is the finer grit side.
The holes were less deep. Averaging about .002 inch
But
the grit size is ~ 325 or 45 microns = ~ .00178 and as we saw earlier the swarf is going to be smaller than that so that .002 hole depth on the blue side is looking pretty adequate.
What ?

[David Barnett]

...sometimes a cigar is just a cigar.

[David Weaver]

How well do the eze-laps work for flattening? I know folks like them the best for actual honing, but do they make decent flattening stones as well?

They would probably work like a diasharp. Mine has a clump of diamonds on one corner that would scuff a fine stone a little bit, but they could be filed off without issue if I wanted to use it for that.

The atoma is definitely nicer for flattening/refreshing stones.

[Mike Brady]

"Last edited by Winton Applegate; Today at 3:14 AM." .........:rolleyes: Dude, get some rest!

[Winton Applegate]

3:14 AM

Vulcans often go days without sleep. Besides, sleep cuts into my coffee drinking time. Spelling Earth English properly is a huge drain on my constitution. Some times I have to take a break to rest then take it up again. The effect that comes over me is as a fish laying on the beach out of the water;
only I'm laying on the couch.
Strange how all the hands on stuff comes with much energy and enthusiasim. It's just the schpeeeling that wha, wha, whaares me downnnn.
a personal flaw
one of many
it's a burden I must bare
sorry to share it occasionally with you all.
You are very tolerant and I thank you for that.

[Winton Applegate]

...sometimes a cigar is just a cigar
Hey does any body know ; did MacGyver ever save the world with "just a cigar" ? I am slowly working my way through all the episodes but haven't come upon that one yet. I bet there is one though.

[Winton Applegate]

Hey, I "Guessed" right. Imagine that.
See the DMT frequently asked questions list at the bottom of the list
http://www.dmtsharp.com/resources/dmt-faq/#dmt-different-surfaces
Quote =

The polka dots are slightly recessed so that when you are sharpening the small amount of material (swarf) that is being removed will fall into the polka dots and remain out of the way of the sharpening surface, making your sharpening work quick and easy.

As Gomer Pile used to say "Surrrrprise, Surrrrprise, Surrrrprise, "

[Winton Applegate]

Dots saves money
They have to punch out all those dambed holes and replenish the tooling to do it. So that costs them something.
I'm just playing devil's advocate
(last time I was saying dots do save.)
maybe it's a wash.

[David Weaver]

I'd bet dots have a lot more to do with the cost of the base, and the ease of manufacturing a flat hone.

As far as the cost of diamonds goes, I saw those square things that they sell at HF on alibaba, the 2x6 stones with diamonds on four sides. With the plastic tray, they were $1 to $2 each, depending on the quantity you buy.

I have one of the ones from HF, got it when I was trying different small diamond hones to condition the surface of stones (it was about $10 with coupons). There is no shortage of diamonds on those things and someone is making a profit selling really large quantities for $1 each, including the base.

On ebay, good known diamonds from a lapidary supplier are a quarter a carat. So it's unlikely the holes are for the diamond cost, unless that's a holdover from manufacturing them a long time ago. But having a substrate that's easy to affix the wafers to and have them be flat, that's probably a lot more savings vs. a flat mild steel substrate.

[Mel Fulks]

Even ring solitaire diamonds are not really rare in the way gold is rare .All of that is the modern doing of the De Beers company .FRONTLINE on PBS did fascinating documentary on that subject some years back.

[David Weaver]

Mel, I read the same thing a while back, it's only because of supply constriction by one company who would never be allowed to operate the way they do if they were HQ in the US. The estimate in the article I read was that most of the mid-sized stones people buy, like a 1 carat stone, would have a market value of about 50 bucks if the market wasn't manipulated. Of course, if they were 50 bucks, nobody would want them.

They did mention that they thought that the value for the truly rare IF and FL graded large stones would be relatively unaffected because they are.....well, truly rare, unlike most of the stuff that's peddled to us.

[David Barnett]

...but quickly leveled during initial use, leaving colorful little shavings. The DMT rep who gave the answers I alluded to in my previous post told me this was normal during break in. I could actually sharpen narrow chisels on those early stones without edge-damaging catches. Later stones, not so much. Current stones, not at all. No mention of swarf mitigation occurred until later on, as I recall, and now it's a "feature" and in the FAQ—do tell.

So you're right—surprise, surprise, surprise! :)

[Winton Applegate]

That's educational for me. I hadn't seen those. Thanks.
On the rare occasion I go full butt head when somebody wants to show me a diamond ring that they have , in my circle, spent money on they cannot afford just because society told them they had to. . .
They are showing off the ring thing to everybody and they say something like don't you want to see it.


My butt head response can be, depending on my blood levels of chocolate and or coffee verses my exposure to bull sheeet that day, something on the order of :
I like my diamonds in my cutting tools thanks.
or
Oh that's OK I have tens of thousands of diamonds in my back pack.

If they say why do you say that ? Or I don't believe that. etc., I just pull out the two EZE-LAP paddle hones I carry for touch up sharpening of drill bits and other cutting tools at work.
I have mellowed with age.

[Winton Applegate]

now it's a "feature" and in the FAQ
Fascinating !
I stand corrected.
Sorry
You guys sure get around. Decade and a half. I only go back about ten or eleven years on that diamond plate.
Keep keeping me honest.

[David Barnett]

Decade and a half. I only go back about ten or eleven years on that diamond plate.

Closer to two decades, actually.

I didn't think you were incorrect—just that the product has apparently "evolved". Happens. For example, Eze-Lap products have a blend of polycrystalline and monocrystalline diamonds in their current formulation—not an altogether bad thing, by the way—but very few products are immune to change.

I've gone through dozens of rotary diamond laps and they've for the most part improved, become more durable, consistent and far cheaper over the years. Worn ones still have enough life left in them for honing edge tools—mostly gravers—in fact.

I not-so-long-ago priced Asian non-rotary, large, generous rectangular "toppers" for sharpening woodworking tools and they're astoundingly cheap—single digit dollars each if you want a few thousand and intend to sell them, which I don't.