Cliff Stamp
BANNED
- Joined
- Oct 5, 1998
- Messages
- 17,562
Thombrogan has noted previously how to sharpen convex edges on smaller blades on benchstones :
http://www.bladeforums.com/forums/showthread.php?t=371297&highlight=convex+alvin
the same technique can be used to sharpen full convex profiles. On larger blades I find this fairly awkward though. I used to hold the blade fixed and arc the hone over it working in small sections at a time. This is very time consuming though compared to v-grind sharpening, about ten times as long.
After watching Fikes video recently I adapted the a few of the techniques illustrated. I start off sharpening the edge just as if it was v-ground with a 200 grit waterstone, this is really soft and wears quickly. I run the convex edges on chopping blades very close to flat and the natural curvature induced by this stone as it wears is enough to give the taper I want.
When I switch to finer stones they are so hard they won't induce significant curvature naturally. So you have to arc the blade or the hone to generate the curvature. Currently I honing the bevel in sections as Fikes does in his video. I run the stone more on a 45 (he runs it parallel to the edge). I start off working the shoulder of the bevel which is 8/10 on most of my knives and then rotate the blade to hit the very edge which is 12/14.
I use a few light passes on an obtuse micro-bevel periodically for burr minimization and after finishing on usually a fine natural waterstone I use a few passes on chromium/aluminum oxide on leather. The important step is the initial honing on the coarse stone which keeps the profile stable, in the past I have found a tendancy to over thicken convex profiles by increasing the arc too much when sharpening them freehand.
-Cliff
http://www.bladeforums.com/forums/showthread.php?t=371297&highlight=convex+alvin
the same technique can be used to sharpen full convex profiles. On larger blades I find this fairly awkward though. I used to hold the blade fixed and arc the hone over it working in small sections at a time. This is very time consuming though compared to v-grind sharpening, about ten times as long.
After watching Fikes video recently I adapted the a few of the techniques illustrated. I start off sharpening the edge just as if it was v-ground with a 200 grit waterstone, this is really soft and wears quickly. I run the convex edges on chopping blades very close to flat and the natural curvature induced by this stone as it wears is enough to give the taper I want.
When I switch to finer stones they are so hard they won't induce significant curvature naturally. So you have to arc the blade or the hone to generate the curvature. Currently I honing the bevel in sections as Fikes does in his video. I run the stone more on a 45 (he runs it parallel to the edge). I start off working the shoulder of the bevel which is 8/10 on most of my knives and then rotate the blade to hit the very edge which is 12/14.
I use a few light passes on an obtuse micro-bevel periodically for burr minimization and after finishing on usually a fine natural waterstone I use a few passes on chromium/aluminum oxide on leather. The important step is the initial honing on the coarse stone which keeps the profile stable, in the past I have found a tendancy to over thicken convex profiles by increasing the arc too much when sharpening them freehand.
-Cliff