Pressure used on Sharpmaker

WonderMonkey

WonderMonkey

Joined
Apr 18, 2007
Messages
101
I received my sharpmaker the other day, watched the video twice, but of course can't get anything near sharp enough. I'm wondering if I am using too much pressure. The video says "about three pounds" but how much is that really? Is that a feather touch or an actual push against the blade?
 
Don't tell me that - I'm waiting for it to arrive. I hope someone knows the answer to your question.

What are you trying to sharpen?
 
For my first knife I had a ka-bar that I didn't mind messing up (then fixing). It's a standard sheath hunting knife ka-bar. The edge is suppose to be 20 degrees. I used the sharpie trick to make sure I was hitting the edges.
 
Thats in the "light to medium" range, as if the Sharpmaker rod was made of cheese and you are trying to slice some off. Three pounds is not heavy pressure, but is more than "very light".

Dexter - fear not; the Sharpmaker will do you just fine.

right on
 
I gotta say, I am kind of disappointed with the Sharpmaker. I am a novice, but not an idiot. I can't get anything sharp.
 
IMO "about three pounds" is way too much pressure if you're using the corners of the rods, and sometimes the case if using the flats.

If you're touching up an already sharp edge or applying the final edge to a freshly sharpened blade, using that much pressure will weaken the steel, resulting in poor edge retention. To achieve the finest, most durable final edge, you want to use only the very lightest pressure.

When using the flats of the Sharpmaker rods, force should be distributed across a larger width and area of the blade, and so more pressure can be used so long as you're able to consistently maintain good control and not wind up hitting only the edge(s) of the flat. However -- again, IMO -- the Sharpmaker, with only 800 grit medium and 1200 grit fine rods, is really only a finish and touch-up sharpening tool and isn't effective if you need to remove much metal at all even if you're using extra pressure, which again risks damaging the steel.
 
Like DoW said the recommended using pressure of the sharpmaker is actually a bit heavy and can be in a sense multiplied by how much actual surface area the pressure is applied across. If your knife edge is touching the stone at only a very small cross section, say at a small point of edge touching just a small point of the stone(the corners), that recommended three pounds is comparible to ten or twenty pounds of pressure applied to a cross section of your knife contacting an inch of stone at a time. Sorry if that sounded confusing.

The recommended pressure is for steel removal, but won't be very effective at leaving a razor sharp edge. After you get the edge where you want it i.e. the marker wipes away with just a few swipes, then you have to start being a bit more delicate. Think of it like this: you want to wipe or brush away steel from the "perfect edge" that you are trying to find underneath the steel. If you are applying "grinding" pressure, you will always be left with a grinded edge, so you want to start brushing away that rough damaged edge that DoW was talking about withouth damaging or chipping the perfect edge underneath. The thing you have to understand is that the steel is made up of many micro particles that can be ripped away at the edge, and these micro particles are needed to fill in the edge making it more "perfect". Also keep in mind that at medium pressure you can still be folding steel right at the edge and several light strokes may be needed to wipe this fold away, leaving a more perfect edge. Also, it may be necessary to strop to eliminate all of the weakened steel.
 
Excellent. Thanks for the thoughts, everybody. I'm going to go over my knives with a lighter touch tonight.
 
WonderMonkey said:
I received my sharpmaker the other day, watched the video twice, but of course can't get anything near sharp enough. I'm wondering if I am using too much pressure. The video says "about three pounds" but how much is that really? Is that a feather touch or an actual push against the blade?
Click to expand...

I don't think pressure is the problem. More likely the angle of the knife edge does not match that of the sharpmaker and you are not actually sharpening out to the edge. This is a common problem with people new to the Sharpmaker.

I think the Sharpmaker does a dinkum job of maintaining an edge once that edge is at the same angle the Sharpmaker is. Getting the edge to that angle using a Sharpmaker can be a chore.

Do this:
Use a Sharpie to color the edges of the blade, then take a couple of swipes on the Sharpmaker and look at the edge under a hand lens. Wherever there is black, the edge is not hitting the sharpener. If there is black on the very edge, that means you are not sharpening there. Until you can take a couple of swipes and see no black on the very edge, you are still changing the edge angle rather than sharpening.

IF you are only changing the edge angle, you can either keep after it with the corner of the Sharpmaker rods or use a coarse Benchstone. Either way, I would not try to progress beyond the corner of the medium Sharpmaker rod until I passed the Sharpie test.
 
What knarfeng said! I know a lot of guys who thing something is wrong with their Sharpmaker because they have the wrong angle an the blade in progress. I use my Severtech Sharpener, which has a diamond stone, to remove lots of metal for an initial edge. I "touch-up" weekly on the Sharpmaker so my EDC stays sharp for many months before it sees the Severtech again. That thing is a real meateater.
 
probably too pressure is the problem. lighten up on the pressure as the blade gets sharper. when you are trying to get a hair shaving edge the cutting edge should just barely touch the stone with the slightest pressure. something like an ounce or two, not a pound or two.,,VWB.
 
vwb563 said:
lighten up on the pressure as the blade gets sharper. when you are trying to get a hair shaving edge the cutting edge should just barely touch the stone with the slightest pressure. something like an ounce or two, not a pound or two.,,VWB.
Click to expand...

Exactly what I do. I keep progressing on the fine stones until I'm not even using the weight of the knife.

Of course if you had the ultra fine stones you may not have to vary the pressure as you would using only the fine stones to achieve the same results.
 
Extremely light pressure helps to minimize burr formation. But if you're going to strop anyway after using the Sharpmaker, it really doesn't matter much.

As long as you're not applying so much pressure that the base starts to flex, you're doing alright. The main problem with applying excess pressure is that you tire yourself out more, and fatigue can lead to sloppiness.
 
knarfeng said:
I don't think pressure is the problem. More likely the angle of the knife edge does not match that of the sharpmaker and you are not actually sharpening out to the edge. This is a common problem with people new to the Sharpmaker.

I think the Sharpmaker does a dinkum job of maintaining an edge once that edge is at the same angle the Sharpmaker is. Getting the edge to that angle using a Sharpmaker can be a chore.

Do this:
Use a Sharpie to color the edges of the blade, then take a couple of swipes on the Sharpmaker and look at the edge under a hand lens. Wherever there is black, the edge is not hitting the sharpener. If there is black on the very edge, that means you are not sharpening there. Until you can take a couple of swipes and see no black on the very edge, you are still changing the edge angle rather than sharpening.

IF you are only changing the edge angle, you can either keep after it with the corner of the Sharpmaker rods or use a coarse Benchstone. Either way, I would not try to progress beyond the corner of the medium Sharpmaker rod until I passed the Sharpie test.
Click to expand...

I already do the Sharpie thing. It helps. I am hoping practice helps keep my angle but so far it seems far too easy to deviate from the correct angle and mess things up. However many here think the SM is great so I know it can be done. Right now I'm not real impressed. I'm sure the SM isn't too impressed with me either.
 
Also I'm not sure how sharp I should expect the knife to be before I progress to the next one. For example using the corner of the course triangle.... what should I expect before moving to the flats of the course triangle? I'm sure at each stage I shouldn't expect hair shaving but ... what?
 
You should have the knife pretty sharp before moving from the coarse stone to the fine one. I usually work the flats of the coarse stone until I can at least slice paper or shave hair from my arm.
 
People tend to move to quikly to the white fine rods.
First you should be able to pop hair with the medium grey stones. After that you should move to the white's . At the white rods apply no pressure at all let the stones do the work.

For good stainless steels like VG-10 S30V you can thin out the relief bevel this is the metalstock after the actual cutting edge. This way you can be quicker with setting the final edge on a 20 to 15 degree per side.
;)
 
You start heavier and finish softer, the key is to use enough pressure to leave a nice streak of dull steel on the stone, just lighten up until you have a honed edge, if you stay heavy you will weaken the edge.
 
You must log in or register to reply here.
Back
Top