DMT Diamond Stones Not Coarse Enough

Somewhere someone said that the Shapton Glass 120 wasn't a very good stone. I can't remember if it was high wear rate or low grinding power. One of those things sticks in my mind. Jason, you like this stone enough to recommend it. Do you recall anything like what I do about it?

Brian.
 
bgentry said:
Somewhere someone said that the Shapton Glass 120 wasn't a very good stone. I can't remember if it was high wear rate or low grinding power. One of those things sticks in my mind. Jason, you like this stone enough to recommend it. Do you recall anything like what I do about it?

Brian.
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Its all about application, given that they were designed as stone to be used on woodworking tools that is where they excel. Just as the diamond plate excels on high alloy steels and is meh on things like plane blades.
 
You could get Cbn metallic bonded plates. They come in 200x70x3mm and 200x40x5mm. They are expensive but comes from 8000 JIS down to 60. If you will keep in mind that they will last you decades without losing performance they are an excellent investment.
 
Fixed coarse abrasives like those in coarse diamond plates require a minimum amount of pressure to cut. With wide bevels, the contact area can be too large to achieve sufficient pressure (pressure decreases with increasing contact area for a given applied force).

Waterstones can be effective on wide bevels because they release loose abrasive particles that can roll and/or embed proud of the surface.

Coarse Atoma plates are effective because there are fewer contact points than traditional plates resulting in higher pressure per cutting point.

https://scienceofsharp.wordpress.com/2016/12/21/abrasion-rate-vs-grit/
 
I've found the DMT Dia-Sharp Ultra-Coarse (220 grit) works very well on high carbide steels -- particularly S110V.
 
ToddS said:
Fixed coarse abrasives like those in coarse diamond plates require a minimum amount of pressure to cut. With wide bevels, the contact area can be too large to achieve sufficient pressure (pressure decreases with increasing contact area for a given applied force).

Waterstones can be effective on wide bevels because they release loose abrasive particles that can roll and/or embed proud of the surface.

Coarse Atoma plates are effective because there are fewer contact points than traditional plates resulting in higher pressure per cutting point.

https://scienceofsharp.wordpress.com/2016/12/21/abrasion-rate-vs-grit/
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Yep. The DMT XXC also has reduced surface area in contact during honing due to the particles being very sparsely applied to the plates, unlike their finer offerings. I would agree with the correct synthetic water stone being a better overall choice, just didn't seem like the O.P. was interested in such a suggestion.
 
eKretz said:
Yep. The DMT XXC also has reduced surface area in contact during honing due to the particles being very sparsely applied to the plates, unlike their finer offerings. I would agree with the correct synthetic water stone being a better overall choice, just didn't seem like the O.P. was interested in such a suggestion.
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Are you referring to something like the Sigma Power Select stones, (which I've no personal experience with), or something like the bonded diamond splash and go stones?
 
Blues said:
Are you referring to something like the Sigma Power Select stones, (which I've no personal experience with), or something like the bonded diamond splash and go stones?
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Shapton, Naniwa, Sigma, any of those would probably work better for heavy work, but they will go out of flat pretty quick. Honestly, I think the absolute best approach for a lot of material removal would be the one I mentioned earlier - a coarse belt on a variable speed belt sander at a low speed with a good flat platen behind it.
 
Jason B. said:
Its all about application, given that they were designed as stone to be used on woodworking tools that is where they excel. Just as the diamond plate excels on high alloy steels and is meh on things like plane blades.
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That's pretty interesting. Do you mean that the Glass Stone entire line was designed for woodworking tools? Or just the coarse stuff? If you mean the whole line, that's surprising to me since there are a good number of people (I think you included?) that love them for kitchen knives. I was almost seduced into buying some when I watched a video of someone (I think from CKTG) doing a full progression of them on a kitchen knife and seemingly did a very good job without a ton of effort.

Still, I hope that the Original Poster here has good luck with his DMT XXC.

Brian.
 
ToddS said:
Fixed coarse abrasives like those in coarse diamond plates require a minimum amount of pressure to cut. With wide bevels, the contact area can be too large to achieve sufficient pressure (pressure decreases with increasing contact area for a given applied force).

Waterstones can be effective on wide bevels because they release loose abrasive particles that can roll and/or embed proud of the surface.

Coarse Atoma plates are effective because there are fewer contact points than traditional plates resulting in higher pressure per cutting point.

https://scienceofsharp.wordpress.com/2016/12/21/abrasion-rate-vs-grit/
Click to expand...
Likewise too small a bevel or contact area can damage the diamonds if too much point pressure is present. It is amazing how little pressure is needed with good diamonds to cut the hardest steels.
 
bgentry said:
That's pretty interesting. Do you mean that the Glass Stone entire line was designed for woodworking tools? Or just the coarse stuff? If you mean the whole line, that's surprising to me since there are a good number of people (I think you included?) that love them for kitchen knives. I was almost seduced into buying some when I watched a video of someone (I think from CKTG) doing a full progression of them on a kitchen knife and seemingly did a very good job without a ton of effort.

Still, I hope that the Original Poster here has good luck with his DMT XXC.

Brian.
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Yes, the whole line was originally designed for the very hard A2 blades found in some premium wood working tools, IIRC. Us knife guys quickly found the premium abrasive and fast cutting speed of the Glass stones to work very well on not only some of the harder and more wear resistant kitchen cutlery but also do very well with folding knives.

You are correct to think not much effort is needed with these stones. Like a diamond plate they work better with a softer touch and a little more time spent making sure your technique is consistent.

The 500 and 2000 Glass are my most used stones, they are fast and consistent with a wide range of steels while producing a superior edge to most other stones. I also found out via a long road of buying a trying stones that I prefer harder stones. I started with Ark stones and moved on to Spyderco ceramics before finally diamond and waterstones. When I started with waterstones the advice was to use softer stones with knives and harder stones with woodworking tools. I understand now why that advice is given but for me it was a difficult transition to learn on soft stones. I have also come to appreciate harder stones on folding knives because like a diamond hone they stay flat and allow more consistent bevels with cleaner lines.
 
I have been using the XXC. It's better than the XC, but still very slow for working on damaged edges and flattening backs. I have a Millers Falls #14 plane I bought recently, and around 1/16" of the iron has to come off. Tedious.
 
Flattening backs is going to be slow no matter what hone you're using. The more surface area, the slower the going. That's actually a good application for a surface grinder.
 
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