sharpening knives with a curved blade

[albokap]

I carry an Emerson commander, folding pocket knife with about a three inch blade.  The blade is  wider at the outward curve on top and the center part of the knife has sort of a concave  curve to it although not as exagerated as the top curve.  I tried sharpening it as I would a straight blade with disappointing results.  Any tips on how I would go about sharpening a blade like this and maintain an even edge angle throughout the blade?

[lights_out]

Don't do it! It was suggested in another thread that it may be possible if you take the stone grader and radius an edge of the stone you could sharpen the concave section with that curved radius. I tried this on my SOG Vulcan, which has a similar blade shape as your Emerson. I mounted the universal support on the Tormek base so I would be grinding away from me, I figured I could use a lighter touch this way. I checked the bevel angle using the black marker technique, set the angle, and away I went. I took my time and went slowly. The first thing I noticed was it was really difficult to control the grinding of the blade using that small portion of the grinding stone that was contacting the blade. Some spots along that curve were ground more than others, leaving a wavy surface. Second, the angle of the bevel changed as I got into that curve, leaving an uneven bevel along the length of the blade. Lastly, even though I ground the edge of the stone first with the course side of the grader, then the fine side, that portion of the stone left some nasty deep scratches on my blade (not to mention I left a nice groove in my stone grader by grading that edge).

I love my T7! I've never had sharper knives or tools since I got it last year. But like everything else, it has it's limitations, and this is one of them. I have since fixed that knife by wrapping some wet/dry around a one and a half inch diameter piece of delrin and honing it by hand. This is what I should have done in the first place but I wanted to try the aforementioned method. Save yourself some aggravation and do it by hand.

[Jeff Farris]

Albocap brings up some of the pitfalls of grinding concave blades, but let me point out a few issues.  First I gather that he used the jig.  That is not advisable. Anything with a concavity done on the corner of the stone should be done freehand. Next, it is vital that the radiused corner and the entire stone be graded as fine as you can get it.

It takes  some finesse and practice, but it can be done very successfully.