Eze-Lap Diamond Stone Flatness - Am I expecting too much?

[Mark Ketelsen]

I needed to replace worn-out and un-flat Diasharps. So I bought 250 grit and 400 grit 3"x8" Exe-Lap diamond stones because I heard they were flat. When they arrived, they were both convex, so I contacted Eze-Lap and they offered to replace them. Well I got the replacements and they aren't flat either. My expectation was that there would not be any slivers of light under a straight-edge on the surface of the stone (like when I hand-joint stock). This was not the case. When I put my Starrett straight-edge on the surface, I measure gaps of .003" on one stone and .004" on the other with feeler gauges. The stones are convex and these measurements are taken with the straight-edge in contact with the left portion of the stone and the feeler gauge applied at the right side.

I emailed Eze-Lap and told them this and ask them what their flatness tolerance is and whether these are in or out of spec. They never replied.

So I'd be interested in whether others have had better luck or the same experience and whether my expectation for flatness is unrealistic for such a product.

Thanks.

[Tony Shea]

For a stone at that price point i think those #'s are very reasonable. I personally wouldnt hesitate using them.

[Ray Bohn]

I don't have an answer, but I want to thank you for the information. The fact that the manufacturer ignores your questions is enough to keep me away from these folks.

[David Weaver]

I don't think they have a really good matrix for lapping stones, and my two are very slightly different from each other in flatness, but not off by four thousandths or anything.

The two things I'd get to lap stones are a duosharp (the ones with a plastic core) if i could find a suitable one for about 50 bucks, or more preferably, an atoma (though it does cost a little more, stu probably has them relatively inexpensive).

I wouldn't cast those ezelaps aside, though, they are better than duosharps or atomas for sharpening. Maybe not for flattening the backs of wide flat things if they are 4 thousandths hollow, but once you have an iron or chisel in shape, it should never touch anything on the back other than your finish stone, anyway.

[Rich Harkrader]

If you want guaranteed flatness, go with Trend, which are guaranteed to .0005.

[David Weaver]

Trend's guarantee is per inch. They could, in theory, be further out of flat than .004" over their length and still meet their spec (since errors in the same direction would be compounding and not just additive).

Trend's plate looks strikingly similar to the iwood combo plate (that is made in japan and costs half as much), and trend doesn't provide any information on on where they're actually made, but their flatness tolerance sounds similar to iwood.

Not intending to be overly harsh, but I am more critical of companies that rebadge things than companies that make things (because you usually pay a lot more for the same thing, and the thickness of the marketing poo is usually greater to try to justify it).

Trend also makes the errant argument that the (cheaper) monocrystalline diamonds are superior to the (more expensive and nicer to hone on) polycrystalline diamonds. I guess DMT spent enough marketing on that such that other folks also feel like it can just be stated as fact. Experience with a well worn plate of each type will say otherwise, though.

The diaflat is .0005" spec flatness, and certified, but it's incredibly expensive and too coarse for hard fine stones. At about $80 shipped, the atoma is probably the best for waterstones. They have clumps of arranged and spaced monocrystalline diamonds on them (which means that once they wear, they're not impressive for honing, but if you don't wear them, they're great for flattening waterstones), and I've never heard of one that's out of flat. Their only flaw is that they may not tolerate use on oilstones.

[Jim Matthews]

I do all my sharpening right off the Atomas, then strop.

You can get a finer edge with some of the ceramic stones available,
but the Atomas seem to be holding up, and are flat enough for my needs.

FYI - I use them with a little honing oil, instead of water - no rust problems!

[Hugh MacDonald]

Stay away from the Trend, if you're looking for a precision flat plate and if we're talking about their 8" double-sided diamond plate. I too thought it was flat to 0.0005"--that's the claim made in the Trend video with James Barry, in the Rob Cosman video, where he uses and endorses the tool (he sells them in his online store), and in all the Trend literature I could find and read. (David Weaver, could you please let me know where you found that Trend's spec is 0.0005 per inch? I'd be interested to see that. I was certainly confused by the marketing, and I'd like to let somebody know so clarification can be made and others don't make the same mistake I did.)

I'd been thinking about the Trend plate for a while. It looked like a nice stone, and watching Rob Cosman using and recommending it got me interested. When I saw it on sale I finally bought one. When I got it I tested it out on a couple of chisel backs, and it cut really, really nicely, on both grits. The 300 side actually cut faster and left a less obnoxious scratch pattern than my DMT Duo coarse. The 1000 side seemed to cut quickly as well. I was very pleased. Then I checked it for flat. Against a straightedge it was immediately evident that it was grossly out of flat: one side was convex and the opposite concave, so the plate had an obvious curve. Feeler gauges confirmed the observation, showing one side was 0.007" hollow in the middle, while the other was 0.007" at the ends. 0.007". I was expecting a precision-flat plate, and so was disappointed.

By the way, the Trend is made in China, a piece of information left out of all the sales and marketing literature I saw. I now regret not getting the Atoma instead, which I was also thinking about buying. I had questions, if not outright doubts, about the Trend, whereas I knew exactly what I'd be getting with the Atoma, which had been recommended by Stu (of Tools from Japan), from whom I bought my Sigma Power stones, and whom I trust completely.

[David Weaver]

The flatness claim is made on Amazon.

[Tom Blank]

My experience with Trend is similar to Hugh's - although not quite as bad at .007" out. I had a Trend 300/1000, used the 300 side to flatten stones and the 1000 side in place of a 1000 waterstone. Could not figure out why I could not get a flat back on chisels and had problems honing plane blades. The Trend was cupped and was leaving my stones convex rather than flat. Sent it back, and Trend replaced it after arguing with me. The second one was cupped as bad as the first, plus it was very rough along the edges. It has been relegated to general shop use and to hone burrs from cutoffs and from thread cutting on bar stock - it will never see a chisel or plane blade again.

I just got a DMT Dia-Sharp D8F which checks out flat with an engineer's square, will see how it works out.

TB

[David Weaver]

By the way, the Trend is made in China, a piece of information left out of all the sales and marketing literature I saw. I now regret not getting the Atoma instead, which I was also thinking about buying. I had questions, if not outright doubts, about the Trend, whereas I knew exactly what I'd be getting with the Atoma, which had been recommended by Stu (of Tools from Japan), from whom I bought my Sigma Power stones, and whom I trust completely.

This is, of course, only my opinion and not a statement of fact, etc, but for trend to ask what they ask for that hone and have it made in china is highway robbery. I was guessing that it might be made by koyama because it looks identical, but I guess not. Not a big fan of that kind of thing (slapping a name on something made by a third party and charging an arm and a leg for it).

[Rich Harkrader]

Ahh I was going off their marketing claims on Amazon. I use DMT stones myself, but had my eye on Eze-lap since my stones are only 2" wide. The flatness issue plus the fact they've gone up in price 50% lately has convinced me to stick with DMT.

Rich

[David Weaver]

Wow..I just looked up ezelaps prices, they did go up a lot. That's too bad

[bob blakeborough]

As I am going along, I am getting less and less concerned with "dead flat" of anything related to woodworking. Really, looking back, when in the history of woodworking did the concerns of a few thousands of an inch become something we need to fret and worry over? 1,2, 3 and more centuries ago, I don't think they even had the technology to measure or build woodworking tools to this level of tolerance, and for certain the most amazing pieces ever built and still survive today were never built with those types of tolerances in mind. Heck, the wood moves more than that with changes in humidity!

Nowadays I just put tools to work. If I simply set the tools up and they are doing what I ask, I am happy. If they are not working properly, only then do I look into what might be the issue. My sharpening stones still give a mighty fine edge even when the slightest sliver of light is viable under a straight edge. Eventually it needs a flatten but not to the degree that .003 effects my work. There are tons of guys out there who use old cinder blocks to flatten their woodworking stones and they still produce fine edges and make wonderful furniture! I think we can all agree that a cinder block is not manufactured to .003...

Sometimes I think our obsession is getting the best of us sometimes rather than us getting the best of it...

That said, if a company is advertising their products a certain way, less than .002 of variance as an example, and it has .004 of variance, you of course have cause for not being happy, but at the same time, I am not someone who is shopping for woodworking tools with that level of tolerance specifically in mind as a priority.

[Hugh MacDonald]

This is, of course, only my opinion and not a statement of fact, etc, but for trend to ask what they ask for that hone and have it made in china is highway robbery. I was guessing that it might be made by koyama because it looks identical, but I guess not. Not a big fan of that kind of thing (slapping a name on something made by a third party and charging an arm and a leg for it).

David, my sentiments were those exactly as I was discovering the state of my stone, and as I took a few minutes thereafter to think about exactly what was going on. At that price, it's right there with the 10" DMT Duos and more than the Dia-Sharps, all of which are made in USA and are reliably flat, among other things. When I got the stone and unpacked it, there was a little round sticker on the product box: "Made in China." I immediately had a bad reaction, and thought for what this thing cost it shouldn't be made in China. (I did buy it on sale, but still.) Later, as I was inspecting it for flatness, my mind's eye kept seeing the little sticker, "Made in China, Made in China." The whole situation has me rather upset.