Diasharp... Why did I wait so long?

Kaizen1

Kaizen1

Gold Member
Joined
Jan 4, 2006
Messages
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I FINALLY got some diamonds to sharpen with. I recently ordered the coarse diasharp stone. I thinned down the edge on my Paramilitary about 10-15 times faster than if I were to try that with the ceramic stones I have been using for the past couple of years. I can't believe how fast I can grind down S30V now. This is almost as exciting as getting a brand new knife that I've wanted for a couple of months.

Anyway, thanks to all of you who've suggested using diamond stones. I was reading some posts and it finally moved me to order one. And to all of you who are grinding down lots of steel without using diamonds, get a diamond stone as soon as you can. You don't know what you're missing. I'm probably the last one though:o:p
 
Know what you mean, makes you want to sneak in the kitchen and sharpen everything in there.. <g>
 
I just got my first benchstones (D8C, GS 1K, with a GS 4K on the way)... I've only used the Sharpmaker previously. I seem to recall reading that if you're not careful with the DMTs in the beginning, that the diamonds can get pulled off of the stone... is that true? I've been using pretty light pressure on the D8C since getting it earlier this week, trying to work the entire surface, and it has definitely lost some of it's initial coarseness. Does that mean it's broken in? Can (or SHOULD) I use a bit more pressure to reprofile now? Maybe a better question would be, how long should it take to reprofile an inexpensive stainless practice knife from 20 degrees to 15 on the D8C... a few minutes, a half hour, a few hours...? How much pressure do you use? Dry or wet? Thanks!!
 
My experience (similar to others' postings) has been that a new DMT stone will quickly loose some of its initial aggressiveness with the first several uses. This is normal, to be expected. The advice of many has been to use light to moderate pressure on the stones to avoid diamond "tear out", pulling the diamonds off the stone. I have taken this advice and "let the diamonds do the work". My stones seem to be surviving quite well after several months of casual use. Others have reported their DMTs still work well after many years of use (with moderate pressure). "

...how long should it take to reprofile...?" As long as it takes :barf: using light-moderate pressure. I think the blade should glide smoothly and evenly over the stone, not feeling as if it is skipping,scraping or gouging. If you feel like you are bearing down, that's probably too much pressure. Someone may come along who has quantified this in terms of psi. Until then, that my 2¢ worth.
 
My first diamond sharpener I still use .It's many years old !! Then there were only a few diamond sharpeners now there are many - all shapes and grits.With many fine 'super steels' available now ,S30V,3G ,154CM etc diamond makes makes it very easy to sharpen....BTW if you bear down hard with diamond you will remove lots of steel ! Just a couple of light strokes brings it back to sharp.
 
And when you see how quick they lap your old stones, you'll kick yourself for waiting so long.
 
I've been pushing down pretty hard on mine. I don't think I've lost any of the diamonds, but I'll be careful from this point on. I bought the thing to take off metal, I still use my ceramics for touch ups and finishing edges.
 
Consider light to moderate pressure pushing and pulling the blade in BOTH directions on one side when applying a new bevel. It's fast, applies no more wear and tear on the diamonds than in one direction, and is very easy. Try this instead of heavy pressure and your stones will last longer and your sharpening effort will take less time.

NJ
 
The reason I ask is that I've probably spent more than an hour (four or five fifteen minute sessions before getting interrupted or distracted), trying to reprofile a stainless throwaway practice knife on the D8C, but haven't gotten to the edge yet. The sharpie method tells me that I'm getting close, but I guess I'm surprised it's taking so long... and I've only worked on one side so far!! Am I expecting too much from the Coarse, or not using enough pressure, or otherwise doing something wrong?

Oh, and during reprofiling, I assume it would be a good idea to rinse off the stone occasionally? I've mostly used it dry, but tried here and there with a little water.
 
Part of the reason it may be taking a while is that it is difficult (or impossible) for us to replicate the same angle stroke after stroke freehand vs. using a jig where the same angle of attack is applied on each stroke resulting in higher efficiency and quicker progress.
 
I prefer to use the DMTs with a bit of water to keep the swarf from impacting (clogging) the plate and possibly scratching up the nickel substrate that holds the diamonds in place. For reprofiling, I prefer to use the DMT XXC initially instead of the coarse. In general if it is taking a long time to accomplish a sharpening or reprofiling task, use something coarser. I find that a quick way to break in a plate is to flatten a stone. The DMT coarse is my preference for flattening most stones, but I use the XXC for flattening coarser stones typically 500 grit or lower as a general guideline, as well as badly dished stones.

Now if the XXC doesn't cut fast enough for you and you don't have or want to use a belt sander for blade reprofiling, I find Norton Zirconia belts glued to a glass plate (4 inch x 8 inches) in the coarser grits to work quite well (available in 120 80 50 and 36 grit finishes). The coarser you go the deeper the scratches. On Japanese single beveled knives or knives sharpened at very acute angles (less than ~ 7 degrees per side), I use the XXC and below only to get close to having the edges meeting rather than generating a burr, since these 120 and lower grit choices can chip the edge a bit. This saves a lot of time rather than just avoiding these coarser solutions, especially for reprofiling harder steels. Once you get things close, just work your way up to finer grits to remove the coarser scratches. The DMT coarse will remove the DMT XXC scratches for instance.

Until you break in the DMT's they will be more aggressive AND the diamonds are more subject to 'pullout' as they are sticking out further, thus easier to pry out. You'l also be more likely to get a scratchier finish because of the occassional large diamond sticking out further, so especially with the coarse one, you will get a finer finish after it is broken in.

---
Ken
 
Elliott, I agree with your comment and for reprofiling in particular, I often use my DMT plates in the sharpening jig I built which gives me angle control to under 1 degree, 0.1 degrees on a good day.

---
Ken
 
ksskss said:
Elliott, I agree with your comment and for reprofiling in particular, I often use my DMT plates in the sharpening jig I built which gives me angle control to under 1 degree, 0.1 degrees on a good day.

---
Ken
Click to expand...


Ken, those are impressive results to say the least. :thumbup:

I generally sharpen freehand but recently was very impressed with what I could accomplish (very quickly) using the various DMT Diafolds with the Magna-Guide and my old GATCO angle clamp & base.
 
ksskss said:
Elliott, I agree with your comment and for reprofiling in particular, I often use my DMT plates in the sharpening jig I built which gives me angle control to under 1 degree, 0.1 degrees on a good day. ...Ken
Click to expand...

Now that's efficient.:thumbup: It sure beats my free-hand grinding.:grumpy:
 
Elliott,

Here's a picture of my device which incorporates a standard stone holder with the DMT plate installed:

new1.jpg


This page has links to some videos using it and other info.

Here's a sample edge which shows good bevel consistency:

d13.jpg



Note that the angular consistency for a single stone exceeds this value - since the angle is locked in - but when going through a series of stones or plates I can set each stone or plate to within the sub 1 degree accuracy. I can measure it to 0.1 degrees, but I allow for other variables to stay under 1 degree overall accuracy. This accuracy usually allows me to get an exact surface match for the entire bevel surface within a few strokes from the previous coarser grit stone, which you can see under magnification as you are observing the edge during sharpening, unlike what you do during traditional sharpening with the knife above the stone, an essentially blind procedure. This consistency wastes less metal and produces a flatter bevel.

---
Ken
 
Ken,

That's an impressive setup. Nicely done! :thumbup:
 
ksskss---

It looks like a lean, mean grinding machine.:thumbup:

1) Does the stone holder securely suspend heavy stones when up-side-down?
2) I like to spritz my DMTs during use. Will the stone holder easily flip over for spritzing?
3) Do water stones present any special problems?
 
Blues said:
Part of the reason it may be taking a while is that it is difficult (or impossible) for us to replicate the same angle stroke after stroke freehand vs. using a jig where the same angle of attack is applied on each stroke resulting in higher efficiency and quicker progress.
Click to expand...
I think I'm pretty consistent on the angle, because I'm cheating with a 15 degree wedge under my stone. :o


ksskss said:
I prefer to use the DMTs with a bit of water to keep the swarf from impacting (clogging) the plate and possibly scratching up the nickel substrate that holds the diamonds in place. For reprofiling, I prefer to use the DMT XXC initially instead of the coarse. In general if it is taking a long time to accomplish a sharpening or reprofiling task, use something coarser.

Now if the XXC doesn't cut fast enough for you and you don't have or want to use a belt sander for blade reprofiling, I find Norton Zirconia belts glued to a glass plate (4 inch x 8 inches) in the coarser grits to work quite well (available in 120 80 50 and 36 grit finishes).
Click to expand...
Yeah, I'm wondering if I should get an XXC... this is my first foray into benchstones, and I thought the D8C might be a good option to save a bit of money, but I may end up getting it if I find the C to be too slow. Or, since I hope to not be reprofiling that often, there's always the sandpaper option!! In the meantime, I'll keep at it.
 
Elliott, Thank you very much for your kind words. It's very much appreciated.

Zeasor, excellent questions!

I have been able to use large 'brick' sized stones, just so long as you screw them in tight. I haven't had a problem with it. I do have a preference for Shapton GlassStones.

It's very easy to flip the stoneholder without changing any settings as the stoneholder rotates freely about the rod going down the middle of it. In fact by flipping it over so that the stone is facing up, you can sharpen with the stone at an angle holding the blade horizontally. This approach isn't quite as accurate but more accurate than using the stone horizontal. You can as well just have the stone lay flat on the platform and use it traditionally. You can set the sharpening angles from zero degrees up to approximately 45 degrees although many opt for cutting the 'mast' down to only go up to about 22 degrees (per side),.

I'm able to work with all waterstones other than ones with a base, however I can modify it to accomodate them upon request. I would not suggest using a Naniwa 10k stone with this device however as the stone is so soft that you might inadvertently gouge the stone. I only use edge trailing strokes on this stone anyhow.

I've even put a rasp (microplane) in the stone holder and used the device for 'carving precision bevels in wood and plexiglass as a general shaping tool for woodworking applications. If you put a sharpmaker stone in it, it works nicely on serrated edges, using the triangular edge, but unlike the sharpmaker, I can set any angle rather than using preset angles for a bit more flexibility.

DainBramage, BOTH the XXC and C are, for me, the foundation pieces of sharpening equipment in my 'kit'. It's very worthwhile to have both of these if you intend to do anything more than following the factory bevels and never intend to chip or damage tips or otherwise need to repair a knife. In other words, you need them.

---
Ken
 
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