Questions about Spyderco sharpmaker and diamond stones getting dull

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maximus83

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Nov 7, 2011
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Hi I'm new to this forum. Have questions about sharpening in general, and specifically, about the diamond stones for the Spyderco Sharpmaker. Recently I got a pair of these, and I used them to sharpen 2 quality kitchen knives that had gotten really dull. I had 2 observations about the diamond stones:


1. They get dull REALLY fast. After sharpening only 2 dull knives, and using the same surface each time on the 2 diamond stones, those 2 surfaces are completely smooth now. I did not push very hard on the knives, but I did make a lot of passes over the stones and I wonder if I've worn out those surfaces already. They don't feel nearly as rough as the other surfaces. Does this mean that I have basically ground down those surfaces to the point of ineffectiveness after only 2 semi-tough sharpenings? If so, that's very disappointing.

2. It took FOREVER to get those knives sharp. I'm wondering now if I invested in the wrong sharpening system for big jobs. For small jobs--like my own knives that I keep very sharp anyway, Sharpmaker seems to be ok but it seems too slow for big jobs. Even when using the diamond stones.

I like the Sharpmaker for small jobs or touch-up work or serrated stuff. But I'm wondering if the diamond stones aren't really that great, and also if, for tough jobs, perhaps I need to upgrade to a better system. If so, what would that be? Should I free-hand with something like the Smith tri-hone diamond system? Or should I go with the Edge Pro Apex kit?
 
1- the stones could just be filled up with material from the knives and feel smooth to the touch. Try cleaning them with an abrasive cleaner such as bar keepers friend.

2- The sharpmaker should really just be called the sharpkeeper any sort of sharpening job that needs to take off a lot of material such as reprofiling takes forever on the sharpmaker.
 
What skyhorse said.Also I never use the Sharpmaker for removing much metal.I use it only for touching up an edge.For reprofiling an edge I use diamond benchstones.
 
I have had the same experience the Sharpmaker diamond "stones" and the DMT models. The diamonds pull out of the Nickel plate and then the "stones" cut very slowly. So even though the "stones" are still cutting, I don't have the time or the patience to fool with them. I use 1/2"X2 1/2"X11 1/2" Silicon carbide and Aluminum oxide stones to establish and partly polish my basic taper. Then I move to the Sharpmaker.
 
For sharpening my best friend is an 11"x3" benchstone. The bigger and coarser the better.

(you can use a belt sander if you're really careful)
 
Thanks for the replies. To answer those who asked if I cleaned it, yes I scrub my stones with a toothbruth and Dawn detergent, rinse with water, regularly. And I did before both of these sharpening sessions I mentioned. It is very clear to me that the 2 surfaces I used, are MUCH smoother than they were when I bought them, and also much smoother than the remaining diamond-impregnated surfaces. I was hoping somebody would say something like: "Don't worry about it, that's to be expected and the stones will still cut just fine." In fact, my impression is looking like it may be correct: these stones DO wear down quite quickly, if you use them for big sharpening jobs (in my case, 'big sharpening jobs' meant 2 very dull kitchen knives that required a lot of passes on the stones--like 100-150 passes per blade).

In general, the response that others have made about getting a larger bench type of stone for profiling work, and then viewing Sharpmaker more as a "SharpKEEPER", kind of makes sense to me after my experiences. It's a fine tool and I'm not knocking it. Just trying to figure out where it fits in overall on the knife maintenance spectrum. So, what I'm thinking about doing is getting a Smith diamond bench stone for heavier and profiling work.

Would appreciate any other suggestions on what I should get to supplement my SharpKeeper. :-)
 
Check out the Work Sharp Knife and Tool Sharpener. Basically, it's a miniature belt sander. Not much of a learning curve to it, and it's fast once you do get it figured out. My Wicked Edge hasn't left the closet since I got a work sharp.
 
Sometimes I'll use a Lansky kit to get an edge nice, or close to nice. Then finish with the standard Sharpmaker kit, which can easily get a blade to slice paper without too much work. Clean the rods, it makes a big difference.
 
I wouldn't recommend a large diamond bench stone. I wore out several DMT 4X10 "stones" in short order.
 
DMT's Diasharp stones are known to be some of the best diamond sharpening stones on the market. They are a bit pricey but those that use them, love em. You will need to learn how to sharpen free hand though.

I've also heard of paper wheels used with a bench grinder. That set up is supposed to provide sharp edges in very little time.

If you head on over to the Maintenance/Tinkering subforum you will find a lot of information on sharpening. I've skimmed some threads over there and was surprised at the level of knowledge shared. I'm sticking with my Sharpmaker for the time being as money is tight. I do plan on upgrading my sharpening set up in the future, however.
 
Diamond hones from reputable makers (DMT, Eze-Lap, Lansky, Gatco, Spyderco, etc.) generally will only wear out prematurely for one reason: using too much pressure, which rips the diamond particles out of the nickel substrate. Diamond hones will always go through a 'break-in' process, and will feel smoother to the touch with some use. The most difficult thing for most people (including me) to learn, about using diamond hones, is just how light the pressure can be for the the hones to be real effective. Diamond is so much harder than the steel, and will rip through it with little pressure applied (see how little effort it takes to scratch a polished knife blade, with an accidental feather-light brush against a diamond hone). Some 'simpler' low-alloy steels will feel almost buttery soft on a diamond hone. A burr can be created very quickly on these steels, using a diamond hone, and can also be erased in a single pass. I've done this, and it makes it very hard sometimes to detect the burr, if you're not watching very closely; it's there, then it's gone. So applying too much pressure is counter-productive most of the time anyway. Some of the high-alloy steels, like S30V, will be a little tougher on diamond hones, if too much pressure is used. It's not the steel being tougher/harder than the diamond, but the steel in relation to the holding strength of the nickel substrate, which is limited in it's ability to hold onto the diamond particles. Using too much pressure with more abrasion-resistant steels will only do more damage.

Keep the pressure LIGHT, and your diamond hones will be OK. Keeping them clean will also reduce the temptation to 'bear down' a bit, if the hones are getting clogged and ineffective. :)
 
Good points about how light you should go with diamond hones. I thought I was going with a light touch, but apparently could have gone even lighter.

In terms of sharpening options that are more aggressive than the Sharpmaker, I get that a belt sander would be a good option, but I don't have a ton of space and probably wouldn't use enough to justify. I just want something manual that would be a BIT faster/more aggressive than Sharpmaker. Sounds like a diamond bench stone is prob the way to go.

I have my eye on two bench stones. Anybody know anything about these or recommend them?

DMT 8" stone with base, 2-side (coarse/extra-course):
(( not a paid BF Dealer ))

Smith Diamond tri-hone (includes 3-sided base plus coarse, fine, and Arkansas stones, includes angle guide)
(( not a paid BF Dealer ))
 
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Go with the 8" DMT. To complement the sharpmaker, you only need the coarse/extra course.
The tri-hone is meant to do the whole job on its own.
 
You've used too much pressure if they're smooth already. Having said that, I too did this and I don't think it required much pressure at all (basically crap quality). You can buy diamond sprays to reapply the surfaces, but honestly, the diamond rods are crap.
 
Light pressure is the key to longevity of diamond plated sharpeners. Light pressure will also help you avoid creating a large stubborn burr which you may have trouble removing in some steels. Lighter pressure on all steps of the Sharpmaker system takes a little longer but I tend to get a better edge in the long run. If I could only have one hand powered sharpening system, It would be the Spyderco Sharpmaker. I am thankful to have some mechanical sharpening options to compliment my hand powered sharpening gear. It does save significant time when compared to hand powered only. :)
 
Reading these posts I see that I probably have always applied too much pressure to diamonds myself as I have never been able to get them to work worth a darn. For reprofiling I use Norton India stones and oil. I use the Sharpmaker for all touch ups and for final polish after the India. I have been doing that for about 15 years now and even though i experiment with other stuff I keep coming back to that.
 
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