My tips for the Sharpmaker. Please add yours!

ThinkOfTheChildren

ThinkOfTheChildren

Joined
Jul 7, 2000
Messages
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I wrote this to e-mail to a friend who just got his Sharpmaker. I figured I might as well post this online as well. Please add your own tips.

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Here are some tips that I have collected over time from using my Sharpmaker. I’ve found some of the tips myself and some have been taught to me. Hope some of this can be of help to you.

For a while I always went from step #1 through #4 on every knife. While this might make for an edge that will shave it’s not always the best edge for the knife. If you are not familiar with the 4 steps as outlined in the manual they are as follows:
#1. Corners of gray stones
#2. Flats of gray stones
#3. Corners of white stones
#4. Flats of white stones
Step #1 will give you the coarsest edge which has the most “micro-serrations.” This edge is great for really rough cutting on rope or cardboard. The toothier edge will saw more. The cuts produced by this edge will not be as clean and don’t try to shave with it! This edge will not be good for whittling or very fine tasks.
Step #4 will produce a shaving edge. This edge is best for fine tasks and the smoothest cut. This edge, however, might slide right off of coarser mediums.
#1 and #4 are at opposite ends of the spectrum with #2 and #3 being less extreme versions of #1 and #4 respectively.

Spyderco recommends using the 30-degree slots for back beveling and the 40-degree slots for the edge. This is fine on your average knife. You can also use the 30-degree slots to form the entire edge. This will produce a sharper edge, which will cut more aggressively. Since it is thinner, however, it is weaker and will not be well served for chopping or extended hard use. So how do you decide what edge angle to use? Go by these decisions:
1. What will the knife be used for?
If the knife will see hard use for long periods between sharpening, then stick with 40-degrees. If your knife mostly does easy chores or you like to sharpen it a lot then try a 30-degree edge: I think you will be pleased with the increase in performance.
2. What steel is the blade composed of?
Harder steels will obviously hold that thinner edge better. Don’t chop though! You don’t want to chip out a thin, hard edge. I use the 30-degree setting on my CPM440V Spydercos due to their hardness. Softer steels will roll easier and therefore a thinner edge will deform. Use the fatter edge for softer steels.
3. What is the blade/edge geometry?
I like to use 30-degrees on my full flat grinds such as my Lum Chinese folder. A thinner blade is great for a thinner edge: might as well match up your angles. Don’t even bother trying to put a thin edge on a thick blade: it will not perform well. Stick to the fatter angle on tanto blades or other “big boys.”

Now match angles with coarseness: fatter edges will probably need more coarseness to cut. Thinner edges can be more polished since they will glide through mediums easier.

The Sharpmaker is meant for sharpening, not reprofiling! The gray stones are not coarse enough and you will be trying forever. If you want to reprofile an edge, go for the tip from Shmackey: clip sandpaper onto the rods. Find some silicon carbide sandpaper and decide how coarse you want it. Clip it onto the rods with binder clips to make sure that you are reprofiling at the same angle you will use to sharpen. Thanks for the tip Shmackey!

Serrations are a whole ‘nother issue. Stick with 40 degrees on serrated knives. Use the corners to get in and out of the serrations. The flats can be used lightly just to get the tips of the serrations. Usually stick with the white stones unless you are working with really hard steel.

A big warning: don’t ever let the tip of your knife slide off of the rods repeatedly! This will round off your tip. I like to stop just short of the tip on each stroke and then take care of the tip later.

You can even use the white flats like a strop. Just lightly draw the knife up the white flats a couple of times. This will raise a wire edge. I keep my Gunting at a 30-degree inclusive angle with a wire edge for self-defense. The hair on my arm just runs away from this thing!

I can’t really think of anything else right now. Hope this helps.
 
Bunch of good suggestions. I would only add that I feel only the corners of the fine (white) stones should be used for serrations. The gray stones will remove too much steel.

Also, for most knives, I feel that you can stop after step #3.

Nice, well thought-out post. :)
 
I skip step #3 on ATS-34/154CM and other high Cr steels. I then either strop, or go back to step #2, depending on the use.

Happy sharpening. :)


Steve-O
 
Good information!

I would add the suggestion to always use the safety rods on the Spydie as well as any crock stick setup.
 
I seem to get better results on step 4 if I remove the stone and hold it in my hand. Mind you I do this with the utmost caution.
 
I know this is going to take us off track a bit, but I'm surprised you think of Spyderco's 440V as a "hard" steel. I think of it as soft (and, therefore, weak). At ~55 Rc, it's not hard compared to, say, ATS-34, which is often around 60 Rc. Maybe you have an older version of Spyderco's 440V, when it was harder?

Instead of having a beginner user trying to figure out if his steel is "hard" enough, or "tough" enough, to take your advice and go down to 30 degrees, I feel a progressive, easy-to-understand edge refinement process is what works best. The objective is to get as thin an edge as possible (for best performance), provided the edge does not chip, indent, or roll inordinately during your hardest uses. So, whatever your edge is at now, if you've been using it hard and it's not chipping or rolling, try taking it a little thinner. If you have 20-degree bevels, try laying down a 15-degree backbevel to within 1/64" of the very edge, and then finish on the 20-degree stones. If your edge is still holding up fine, try going down to a straight 15-degree edge (with a few light 20-degree strokes at the end to double-grind off the burr).

Progressively taking the edge down lets the user see some performance gain, while minimizing the chance of making a big mistake that results in bad edge damage, and it also lets the user break up the marathon re-profiling sessions before too much boredom sets in (hopefully :) ).

The first time I sharpen a folder, I actually take it right down to a 15/20 edge. If it does well, I drop it to a straight 15. I don't ever go to a straight 20-degree edge, unless I'm reprofiling an especially wear-resistant steel (like 420V) that was left very thick, and I just get bored and want to stop at some point.

Joe

PS: oh yah, best trick going: use magic marker to gauge your progress! This is especially important on the sharpmaker, where reprofiling can be slow.

PPS: Another good trick: get an x-coarse stone (like a DMT x-coarse), and lean it up against the spyderco stones. It lets you get faster cutting action for reprofiling, but keep the exact same angle.

Joe
 
Ooops! Regarding your point #3

Don’t even bother trying to put a thin edge on a thick blade: it will not perform well
Click to expand...

Heh, you get yourself a Boye hunter in your hand, and you'll retract that statement! For shallow-type cutting, and in fact any cutting that isn't deep in very binding materials, the edge itself is the main determiner of performance. That's why an incredibly narrow blade made from huge thick stock like the Boye hunter can easily outcut just about everything else -- Boye understands killer edge geometry, and despite that huge thick edge, the knife cuts like you won't believe. So it can make sense for a thick blade to have a thin edge, and it really does work.

Joe
 
Joe,

I didn't realize that CPM440V had that low of a harndess on the C scale. In my experience it has been pretty hard. It takes me longer to get an edge on it than most of the knives I work with. I have had no problem working with it at 30-degrees. I have a PVC pipe set up with clothing wrapped up on it for slashing practice with different knives. My Gunting goes through a lot of denim very easily, and can take a nasty chunk out of the PVC without damage to the blade. It is certainly harder than the 154CM currently being used by BM. In my limited experience, harndess values on paper haven't translated into real world experiences for me. Probably has a lot to do with the fact that heat treats vary from company to company (or even within). I don't think I would be out of line in saying that a lot of companies are BSing us when they advertise certain hardness levels on their knives.

As to telling my friend to just keep trying different edges: I know for a fact that he won't spend that much time on this. I know what knives he owns and I sent him a list of how I think he should sharpen the different ones.

As to the Boye hunter: I've never handled one. I've never been able to get a thin edge to perform on a thick knife but it looks like I've been doing something wrong.
 
I think that overall your advice and tips were very good. Nice of you to take the time to help someone out, as well.
I don't agree that "big" knives mandate a thicker edge, but the knife's blade material and intended use do (you actually made this point yourself in the body of your message-at least about use and material).
Also, a thinner edge is not necessarily a sharper edge, though it will cut better because it's...well, thinner (less resistance).
Good stuff, that should be of interest to all of us.

440V may be harder to sharpen than ATS-34 because of increased wear resistance, as opposed to hardness (see the V). Both of my 420V blades are ~57Rc, and are much harder to reprofile than ATS-34 or BG-42 at ~60Rc.
Very easy to touch up, though, thank goodness.

Great "tip" on the tip. All mine are rounded:rolleyes:
 
Even after 8 months using my Sharpmaker I am still learning. The bit about "A big warning: don’t ever let the tip of your knife slide off of the rods repeatedly! This will round off your tip." I wish I had read that many months ago. Took me awhile to figure out why I was having so much trouble with the tips. Wasnt till I decided to try using the sticks free hand on a large, recurve 440V that I figured out what I was doing wrong.
BTW, I tried the sandpaper trick when I first got the Sharpmaker but didnt like the muss and fuss factor. I bought a complete set of DMT short stones and use a ty-wrap to secure it (near the top of the stone) to one of the brown rods. Slippage is minimal, and profiling is easy. Be warned though that you will have to use the DMT stones from then on for that knife for if you try to go back to just the ceramic rods, the angle is just different enough that you will just be spinning your wheels. Nice for M2 steel though.
That was a good post Thinkof... should be added to the Talmidge.doc and the one about sharpening the 710HS (forget who did it).
Rad
 
I would appreciate Feedback on the Convex Edge Kit and process I posted yesterday.

Can you reproduce positive results with what I posted?

Do you have recommendations on improvements?

I am actually pretty excited with the results I achieved.
 
Here's my tip: Don't let the knife too dull before taking it to the Sharpmaker. It does an excellent job of touching up an edge that isn't in too bad a shape, but as has already been stated, it isn't the best for reprofiling or repairing a damaged or badly dulled edge.
 
Originally posted by SDouglas
I would appreciate Feedback on the Convex Edge Kit and process I posted yesterday.

Can you reproduce positive results with what I posted?

Do you have recommendations on improvements?

I am actually pretty excited with the results I achieved.
Click to expand...
SDouglas-- I must have missed it. Where did you post it? Sounds interesting.
--Josh
 
r.e. the rounding of the tip - I draw the blade down the rods from hilt to tip, stopping just short of the tip. Then, when the bulk of the blade is sharpened, I repeat the process just for the tip, but in reverse, leading with the tip. That way you can control the edge & won't "drag" the tip across the rod, which rounds it. Am I expressing this clearly? It's easy to show, hard to explain - just do it in reverse. Nice, pointy, sharp tip.
 
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