Cliff, one more

[Uncle Screwtape]

Cliff,
The April 2000 Blade magazine addresses a few steeling hone questions, have you read it yet? There is a suggestion of vertically holding a steel then pulling the edge heel to tip downward; this is contrary to your advice of pulling the edge away.

My primary concern with using a steel,or ceramic rod for that matter, is the difficulty in maintaining the proper edge angle. This is why I have been so enamored with the spyderco sharpmaker and A.G. Russell's field sharpener. Would I alter the double convex edge of my Battle Mistress by reversing the blade magazine technique; pulling heel to tip upward?

Having already maligned the set angle of the sharpmaker, do you regard the Razor-Edge, Raz-R-Steel as disdainfully? Again, I would use it in reverse as well.

Cordially,

Screwtape

 

[Cliff Stamp]

Screwtape :

There is a suggestion of vertically holding a steel then pulling the edge heel to tip downward

This is a technique commonly used with butchers steels and soft kitchen knives. It is used to file the blade and generate an aggressive edge. A rolled edge which is stroked in this manner will have the rolled part filed off, or on harder more wear resistant blades, pushed flat against the edge.If on the other hand you stroke away from the edge you will straighten out the rolled steel and put it inline with the rest of the edge. Both methods have thier uses, they just do two different things. My brother currently uses a butchers steel stroking into the edge to maintain the edge on the Talonite blade I gave him awhile back.

My primary concern with using a steel,or ceramic rod for that matter, is the difficulty in maintaining the proper edge angle.

You don't really have to be that precise. You are not actually sharpening the blade, that would take forever with a rod. All you are doing is giving a basically sharp blade a little push back into place.

Having already maligned the set angle of the sharpmaker, do you regard the Razor-Edge, Raz-R-Steel as disdainfully?

I have the Raz-R-Steel, I don't use the angle guides on it, but rather extend both rods straight out and wipe them down the blade away from the edge. I have not used the Razor-Edge clamps, nor the stones, but similar to the Sharpmaker I think you are wasting a lot of performance potential by using one angle and one grit on blades of vastly different steels and design. For example, here is the performance of a Boye Dive knife in dendritic Cobalt at 4 different grits :

<table>
<tr><th align=left>Edge finish</th> <th>Performance</th></tr>
<tr><td>800 ceramic rod</td><td>45.90 +/- 9.80</td></tr>
<tr><td>800 waterstone</td><td> &nbsp;&nbsp;4.33 +/- 0.32</td></tr>
<tr><td>600 DMT</td><td> &nbsp;&nbsp;1.73 +/- 0.13</td></tr>
<tr><td>220 Silicon Carbide</td><td> &nbsp;&nbsp;1.50 +/- 0.10</td></tr>
</table>


The numbers are the required amount of strokes necessary to cut through a double layer of stitched denim under just the weight of the knife. It seems obvious that the SiC finish easily outslices the others, so it is the clear winner, correct? Well not exactly. The large microteeth left on the blade make it very hard to do push cuts and they also deform readily under impacts.

In fact you can't even say, well I'll leave all my slicing blades at 220 SiC. Why not? Some steels like D2 tend to slice really well even at high finishes and even at a decent polish can still bite readily. With them you can go to a higher polish and still have a functional level of bite. While they will slice better at lower finishes, the increase will not be as dramatic as the above and the loss in push cutting ability would probably outweigh the gain in slicing performance.


-Cliff

[This message has been edited by Cliff Stamp (edited 04-03-2000).]