when do you know when your knife is sharp?

[mosquitojoyride]

i've been using hte sharpmaker for two days now, and at mots i can get my knife to cut the tip of a looseleaf, but only if i pull it down. i can also push cut. but i can't cut a tip just by "moving" like i can with the caly zdp. is the caly knife too sharp? i can also shave my fuzz hair on my face a little, but i don'tknow if it's sharp enough.

 

[Rat Finkenstein]

if it can shave, it is pretty sharp. I think you could get it sharper with the sharpmaker if you got the ultra fine rods. and you can strop it, too.
I have never seen a knife I would consider "too sharp"

 

[Esav Benyamin]

The Sharpmaker is easy to learn to use, but experience will improve your technique, and the sharpness of the finished product.

Be sure you maintain a vertical blade and stroke down the rods lightly and evenly. I like to use a sabre grip to keep the blade vertical: keep your thumb stretched out on the back of the blade.

Comparing anything to a new Spyderco, especially one optimized for sharpness like a Calypso, let alone the new ZDP Calypso, will leave you somewhat disappointed in your own work. Don't be! You're doing fine, and will do better.

I recently picked up a new knife, the Strider ED, a small fixed blade. After using it a bit, I wondered how sharp it really was, and laying the blade flat on my arm, moved it forward, and saw the tops of the armhair falling away as the blade touched them.

That's a bit better than I usually try for myself!

 

[DGG]

i've been using hte sharpmaker for two days now, and at mots i can get my knife to cut the tip of a looseleaf, but only if i pull it down. i can also push cut. but i can't cut a tip just by "moving" like i can with the caly zdp. is the caly knife too sharp? i can also shave my fuzz hair on my face a little, but i don'tknow if it's sharp enough.

You probably already know this but when you get a new Sharpmaker you have to rub the ceramic rods together to get the gloss off of them or it takes some time before they really start to sharpen. You can grab a kitchen scrub pad and some Bartender Friend (AJAX type cleanser) and wash them good. This takes the gloss off also. When finished scrubing the rods you can then enjoy a real "bartender's friend" (after you have finished sharpening too).

I never could understand two things relating to the Sharpmaker (which I use and like).

The first is why you have to rough up the rods yourself. It seems they should come from the factory ready to go.

The second thing that strikes me as peculiar is why the Sharpmaker tells you to sharpen at 40 degrees when Spyderco ships most of their knives sharpened at 30 degrees. It seems that they should have the profiling, initial edge set at 20-25 degrees and the final sharpening angle at 30 degrees.

I know about shoulders and profiling so don't anyone start flaming. It just seems inconsistent on their part to tell the user to do one thing when they don't follow their own recommendations. Thoughts?

 

[Cliff Stamp]

is the caly knife too sharp?

As a knife gets sharper it cuts easier for longer, no you can't have this too high.

but i don't know if it's sharp enough.

If knife has the ability to slice a piece of paper (which is maybe 10% of optimal sharpness) there isn't really anything you can't do with it, it just gets easier when the knife gets sharper.

How sharp you run the knife depends mainly on your skill. At some point you have to ask yourself how much effort will it take to gain the next little bit of performance and is it worth the time.

The first is why you have to rough up the rods yourself.

Because most people would rather do it themselves than pay Spyderco to do it for them.

The second thing that strikes me a peculiar is why the Sharpmaker tells you to sharpen at 40 degrees when Spyderco ships most of their knives sharpened at 30 degrees.

Because if they shipped them at 40 degrees it would be very frustrating for the users to sharpen them. It is common to see references to hours on a Sharpmaker on non-Spyderco knives.

Shipping them at 15 degrees allows trivial sharpening on the 20 degree settings which is more for a utility tool, and then those that want more cutting optomization can use the 15 degree settings directly.

-Cliff

 

[DGG]

Cliff,

I understand what you are saying and you make good points.

However, I feel that most folks buying a sharpner expect it to work out of the box without having to break in the ceramic rods. I'd gladly pay an extra dime to have them come ready to go.

Also, I would rather have a Spyderco knife arrive sharpened at the angle they say to sharpen it in their instruction booklet and in their DVD/Tape that comes with their sharpener.

By using a more accute angle of 30 degrees inclusive the blade will cut easier (not necessarily better) than at 40 degrees in most instances for the initial cuts. The downside is that it might not hold the edge as long or the edge may be weaker.

With the good quality steels they use in their knives I would think they would profile at 25 degrees inclusive (12.5 degrees per edge) and sharpen at 30 degrees (which is the way they ship them new in the box now). Again I would toss in another dime to have it done by the factory.

I'm a fan of Spyderco knives but I wish I didn't have to spend the time messing around sharpening them to their best angles.

Just my $.02.

 

[5pins]

It is common to see references to hours on a Sharpmaker on non-Spyderco knives.

You can say that again.

 

[Cliff Stamp]

I would rather have a Spyderco knife arrive sharpened at the angle they say to sharpen it in their instruction booklet and in their DVD/Tape that comes with their sharpener.

If the edge was ground at the same angle NIB you sharpen it would take forever to sharpen. The ease of sharpening that Spydero's get is precisely because they undercut the angle allowing a quick application of a micro bevel, this also gives them better cutting ability. Durability is always an issue, but on most materials edge retention is higher with the lower angles. Buck has CATRA graphs which show this for example.

With the good quality steels they use in their knives I would think they would profile at 25 degrees inclusive (12.5 degrees per edge) and sharpen at 30 degrees (which is the way they ship them new in the box now).

In general the higher end knives have lower angles with no micro bevel, most of the ZDP Calypso's are close to 10 and in general the high end flat ground slicers are under 15.

You can say that again.

This is really a wrong tool application though, reprofiling a folder should only take a few minutes with the proper hone even on the hard to machine steels. I just hacked the edge off one last night, S30V, 60 HRC, 4" blade, I did it before the commercials were over while watching tv.

-Cliff

 

[C. Peláez]

And what hone did you use? DMT?

 

[Shmackey]

You really don't need a DMT hone to do it (not that they're bad). A regular SiC coarse stone will do it just fine. The hardness of that stone is so far above the hardness of knife steel that the difference between 58 and 64 RC is trivial.

 

[Cliff Stamp]

A SiC waterstone cuts a completely class above the x-coarse DMT in terms of speed. It is like comparing the speed of a man running to driving a car.

-Cliff

 

[C. Peláez]

Thank you, Cliff, for the tip.