DMT stones, polka dot or un-interrupted?

R

rusty edge

Joined
Nov 2, 2005
Messages
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Hey everybody, I am going to buy some DMT bench stones for reprofiling and want to know the differences between the polka dot looking ones and the un-interrupted stones. Which is better?
Also, I am buying these mainly for reprofiling, but if I was to use a fine or ultra fine DMT stone, would it sharpen has well as say a Spyderco fine or ultra fine ceramic stone?
Thanks for any input, sean
 
rusty edge said:
Which is better?
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The dots are supposed to remove debris, those are the ones I have as bought them awhile ago, if i was getting them now I'd get the full plates. Points can catch in the holes, plus you just get more abrasive.

Also, I am buying these mainly for reprofiling ...
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This is a waste, use a SiC x-coarse waterstone instead.

...a fine or ultra fine DMT stone, would it sharpen has well as say a Spyderco fine or ultra fine ceramic stone?
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DMT fine (red) is about twice as coarse as the sharpmaker medium rods, the x-fine diamind is inbetween the medium and fine rods.

-Cliff
 
Cliff Stamp said:
This is a waste, use a SiC x-coarse waterstone instead.
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Maybe--I think it depends on the user. If you shop around, you can get a DMT X-coarse for the same price as the big ol' green Sun Tiger from Lee Valley. The Sun Tiger cuts faster, but it does require the whole water thing and will dish out. The DMT won't cut as fast, but it's a lower-maintenance stone.

I use the SiC x-coarse stone, but I can see why some folks would go for the DMT--assuming they get a good deal on one.
 
Thanks for the replies guys!
I considered the water stone, but I want a maintence free stone that won't dish or require soaking.
Sounds like I should get the un-interrupted DMT, but should I get coarse or extra coarse?
 
For reprofiling, get the coarsest one you can. As Cliff has pointed out, the waterstones will be faster, but you do need to go through the ritual.
 
Shmackey said:
The Sun Tiger cuts faster, but it does require the whole water thing and will dish out.
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You can just store it in a jug of water, and the dishing doesn't matter for rough work significantly. If however this really does bother you, use sandpaper belts, these are really cheap, get 80/100 AO, stick it on a piece of hardwood and use it like a file.

rusty edge said:
.. coarse or extra coarse?
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X-Coarse for reprofiling. The main issue with these is force, don't use too much, they are really aggressive and should cut well even if you go light, if you press hard you can wear them out prematurely.

-Cliff
 
I do all my reprofiling and preliminary sharpening with cheap two sided stones I bought for 1 Euro each, size 20 x 5 cm. They're either SiC or alumina. Efficient, flat, and wears evenly. I was surprised at the quality, as I bought the first one with doubts. I quickly got two more. The finer side leaves a good base finish to continue with a 1000 grit waterstone. You can work these dry as well, but wet is more efficient, and the dust will not end up all over the place.

Just to make it clear, I don't reprofile the main grinds, just the secondary ones. Why would I get a knife with a main profile I don't like..?

For some really quick and dirty work I also use files meant for sharpening powersaws. These are the hardest, best quality, non-expensive files I have found sold here.
 
For reprofiling work I also would say go for the cheap coarse black silica carbide hones found at just about any hardware store. I think I got a 3x7 one for $5
 
Cliff Stamp said:
X-Coarse for reprofiling. The main issue with these is force, don't use too much, they are really aggressive and should cut well even if you go light, if you press hard you can wear them out prematurely.

-Cliff
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Just want to highlight Cliff's point! Too much pressure can strip the diamonds out of the plate so use a light touch and let the diamonds do the work.

Also, on a fresh plate, some of the diamonds will be riding high and will make the plate seem to cut faster and seem coarser than it really is... these will eventually fall out or wear down to the average level of the rest of the diamonds and the plate will start cutting more slowly and leave a finer finish.... it is not worn out at this point, just "broken in" I have a 20 year old Ez-Lap xtra fine that most people would say is worn out, but no, it still cuts and leaves a finish similar to my Shapton 2k waterstone.
 
rusty edge said:
Hey everybody, I am going to buy some DMT bench stones for reprofiling and want to know the differences between the polka dot looking ones and the un-interrupted stones. Which is better?
Also, I am buying these mainly for reprofiling, but if I was to use a fine or ultra fine DMT stone, would it sharpen has well as say a Spyderco fine or ultra fine ceramic stone?
Thanks for any input, sean
Click to expand...

I have the uninterrupted stones and I really like them. I've always felt that what ever justification they had for putting holes in the stones was bunk. I highly suspect it's a cost-saving technique. More surface area makes for more efficient work in my book. Besides, just rinse off and pat dry my stones after every use and they're fine. Just don't press down too hard with your knives, as yuzuha mentioned, it just knocks the diamonds off and doen't really work any faster anyway.

Diamond stones are always more coarse than their stone/ceramic equivilants. Get something nice and smooth to finish off with. Although, I have gone from the fine diamond stone to a loaded strop and gotten very good results.

.
 
The polka dotted ones are more expensive, though I prefer the non preforated ones, but they're hard to keep still on a surface
 
Once again thanks for the replies guys, I read everyones comments and consider them all. After reading this, I am about to order DMT coarse and medium un-interrupted stones. I have looked into the water stones, but really don't want the extra hassle of mainting my maintence equipment.
So, this is more opinion based, is paying almost twice the price for the 8X3" stones worth it over the 6X2" stones?? I will be sharpening some 6'+ kitchen knives, but mostly my sub 4" folders will be sharpened. So, is it fairly easy to sharpen on a 6" stone? Is there a real advantage of 8" stones?
This is a big deal because I can get a coarse AND medium stone in 6" for nearly the same price as only the 8" coarse stone.
 
rusty edge said:
Once again thanks for the replies guys, I read everyones comments and consider them all. After reading this, I am about to order DMT coarse and medium un-interrupted stones. I have looked into the water stones, but really don't want the extra hassle of mainting my maintence equipment.
So, this is more opinion based, is paying almost twice the price for the 8X3" stones worth it over the 6X2" stones?? I will be sharpening some 6'+ kitchen knives, but mostly my sub 4" folders will be sharpened. So, is it fairly easy to sharpen on a 6" stone? Is there a real advantage of 8" stones?
This is a big deal because I can get a coarse AND medium stone in 6" for nearly the same price as only the 8" coarse stone.
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I have the 6", but I asked for the 8" for Xmas.:D
The key to your question is the "almost twice the price" part. I, absolutely, wish I had the 8" stones when I'm working on anything over about a 4" blade, but for the money, the 6" stones aren't so bad. Besides, they're more packable for trips, etc.

.
 
Longer is by far better even with short blades. 2 times the price better? I really couldn't say it is. I for years used a 4 inch stone and got my knives as sharp as I wanted. My best advise is mark a block of wood with the sizes of both on them and do a few sharpening strokes on it and see for yourself if the bigger one is worth it.
 
db said:
My best advise is mark a block of wood with the sizes of both on them and do a few sharpening strokes on it and see for yourself if the bigger one is worth it.
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You're pretty sharp yourself.:thumbup:

.
 
db said:
Longer is by far better even with short blades. 2 times the price better? I really couldn't say it is. I for years used a 4 inch stone and got my knives as sharp as I wanted. My best advise is mark a block of wood with the sizes of both on them and do a few sharpening strokes on it and see for yourself if the bigger one is worth it.
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Good idea, I just tried that, but I used cardboard instead of going through the trouble of cutting wood. My 3" Paramilitary didn't really matter which stone, my 4" Pacific Salt would do fine on either, but prefered the 8"; but when I got out my larger kitchen knives, I could imagine having a hard time keeping a consistant angle on the edge with all the repositioning to get the entire blade length.
Now I am thinking if the 8" coarse would make up for not being able to afford the second 6" medium stone. Could I go directly from a coarse DMT to the Sharpmaker medium?
 
I use the "dots" and have never had any problems with the point of the knife getting stuck. I have them from x-course through fine.
 
See if one of your local knife shops has a coarse diamond hone and a Sharpmaker that you can try. I would not want to make the jump between the two. The diamond hone will leave some really conspicuous scratches in the edge. A medium ceramic hone won't smooth those out very quickly. If you use the edges of the rods you will obliterate the scratches in a reasonable amount of time, but the rod edges will kind of track in those grooves and leave some extra irregularity. The flats will take a considerable amount of time to remove this irregularity.

I would generally look for something that cuts fast and smoother between the diamond and the ceramic. I have an extra-fine diamond hone that does a nice job as a second step. I also have a 1000-grit Shapton Professional water stone that does a real nice job for a second step.

In reality I would just buy a cheap belt sander at Home Depot and get a variety of belts. It will cut faster than the diamond hone and will cost less than a collection of diamond hones or water stones. I did 6 very dull kitchen knives for a friend last week. I ran from 80 to 600 grit on the belt sander then finished with my Sharpmaker. A nice job on these cheap stainless knives took about an hour. The blades were seriously chipped and I removed all the chips and did serious reprofiling on them. The belt sander that I used takes 4"x36" belts. I also use it to sharpen garden tools.
 
Jeff -

What kind of belt sander did you get? Do you have a grinder/polisher also or just use the Sharpmaker?
 
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