Shapton Glass Stone Flattening - DMT "Coarse" enough?

Is there a good rule of thumb for a minimum ratio between the grits of the SG stone and the diamond plate? The SG 500 is 29 microns and the Atoma 140 I use is 100 microns, so about a 3.5 ratio. The Atoma 400 and DMT Coarse are both 45 microns, which would give a ratio of 1.55. Is this too close to 1:1? The DMT X-Coarse is 60 microns, with a ratio of 2.0. Is that high enough to avoid glazing?

Stepping up to the SG 1K with a grit of 14.7 microns, I use the Atoma 400. The ratio is about 3.0. I also use the Atoma 400 on my 2K and 4K, but could I use a DMT Fine? Its grit is 25 microns, with ratios of 3.4 and 6.7 for the 2K and 4K.
 
Jason B. said:
Wowbagger Wowbagger

Nothing wrong with the DMT plates but by using a Coarse 325 mesh to lap the SG500 you are reducing the effectiveness of the SG500. The diamond plate is not Coarse enough to give proper surface texture and you end up with a 500 grit waterstone that acts more like a glazed 1000.
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True . . . that round even the 220 was "polishing" the M4 (made the edge sharp but fortunately it didn't need much metal removed). I was just using the Coarse 325 for the post.

Truth be told I always use the other side of that stone for flattening (the 220 what ever it is).
Sounds like it still isn't optimal.
Thank you for the info and your time ! ! !
 
First, thanks everyone again for all the responses and info. I have a Atoma 140 on the way and getting ready to purchase the Shaptons.

But one more question.

As originally stated, I've been considering the 500 Double Thick and the 2000 stones. The great thing about this set up is I would get the extra thick 500 stone w/ the case/holder. Two birds, etc. I'm not looking for a polished edge. Just something useful for my pocket knives and kitchen knives.

I see there is a 500/2000/6000 and a 500/1000/4000 set available. I would loose the extra thickness on the 500 stone and the case holder. I'm not sharpening a ton of knives and I could always buy a better holder.

Would one of these set be better for my needs? I like the simplicity of the 500/2000 combo but wondering if the extra grit is really needed for an everyday working edge? Again, no looking for a mirrored edge.

Thanks and sorry for the added questions.
 
tiguy7 said:
View attachment 822966 View attachment 822967 I have Shaptons 220, 500, 1000, 2000, 4000, 8000, 16000, and 30000. For regular knives doing regular work, I stop at 2000. So I would recommed the 1st 4. I use my jig over the pond for sharpening. I use the brick in the pond for leveling.
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Nice set up! The more I think about it, I think I will stick with the 500/2000 combo. I have the Atoma 140 coming so if I ever need to reset or repair a really bad edge, I can use that followed by the 500/2000. Once I get used to these, I can always add the 4000 or 6000 if I feel I need more. Guessing the 2000 will be good enough though. I will finish up with a Diamond loaded strop anyway.

Thanks again everyone.
 
Finally received the Shaptons after a brief shipping mix up. Ended up with the Atoma 140, Shapton 500 and 2000 for now. Looking forward to trying them out this weekend. Thanks again for all the help.

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