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help - putting on a convex edge
- Thread starter Geode
- Start date
Cliff Stamp
BANNED
- Joined
- Oct 5, 1998
- Messages
- 17,562
Walker :
Carry some sandpaper and loop it around a tree branch. Make sandpaper out of a piece of fabric and fine river silt, or carry a block of buffing compound with you and load the fabric with that. It is the basic idea that you are interested in, the exact components don't actually matter.
You use the same technique if the edge is convex, or the whole blade is convex. Just lift the blade up a bit on the start if there is a distinct secondary bevel and you want to keep it. If you don't raise the blade up, you will blend the secondary bevel right back into the primary and make the blade fully convex.
The technique Buzzbait described can be used with a solid benchstone as well, though its not as forgiving to sloppy work as a mousepad. I have switched to doing this in reverse actually. I hold the blade fixed and move the hone across the top of it. Controlling the angle is much easier than with a secondary flat ground edge.
You want to keep the edge perpendicular to insure the edge angle is constant across the blade. You just eyeball this of course, you can do it easily to within a very tight tolerance.
-Cliff
Carry some sandpaper and loop it around a tree branch. Make sandpaper out of a piece of fabric and fine river silt, or carry a block of buffing compound with you and load the fabric with that. It is the basic idea that you are interested in, the exact components don't actually matter.
You use the same technique if the edge is convex, or the whole blade is convex. Just lift the blade up a bit on the start if there is a distinct secondary bevel and you want to keep it. If you don't raise the blade up, you will blend the secondary bevel right back into the primary and make the blade fully convex.
The technique Buzzbait described can be used with a solid benchstone as well, though its not as forgiving to sloppy work as a mousepad. I have switched to doing this in reverse actually. I hold the blade fixed and move the hone across the top of it. Controlling the angle is much easier than with a secondary flat ground edge.
You want to keep the edge perpendicular to insure the edge angle is constant across the blade. You just eyeball this of course, you can do it easily to within a very tight tolerance.
-Cliff
Thanks, all. Ben and Buzz, I now know enough to be dangerous. I think I'll pick up a Buck Filet knife to practice on.
Hoodoo, thanks, it took me a few guesses as to what that thing did, untill I actually looked at it. (I first thought it clamped to something else.) That clamp keeps you from having to use the spray adhesive to stabilize the "sandpaper," as referenced in Ben's link, I take it. From what I see of the wear marks on your Marbles, it appears as if you pulled (?) the knife perpendicular to the spine, right? Does that mean you worked on approximately one-inch sections of the blade at a time?
Edited to reply to Cliff's response: Thanks, I like the cloth and river silt field expedient. I understand now the "sweep" is not a good idea.
Walker
Hoodoo, thanks, it took me a few guesses as to what that thing did, untill I actually looked at it. (I first thought it clamped to something else.) That clamp keeps you from having to use the spray adhesive to stabilize the "sandpaper," as referenced in Ben's link, I take it. From what I see of the wear marks on your Marbles, it appears as if you pulled (?) the knife perpendicular to the spine, right? Does that mean you worked on approximately one-inch sections of the blade at a time?
Edited to reply to Cliff's response: Thanks, I like the cloth and river silt field expedient. I understand now the "sweep" is not a good idea.
Walker
Ditto that last question by Walker. What do you do when the blade's much longer than the width of the strop? Do you strop in sections? Similarly, for blades that have a straight belly and then curve upward sharply to the point...I imagine you'd have to strop belly and surve in separate sweeps, correct? Or is there some magical way of stropping the entire edge of the blade in one sweep?
I'm fascinated by convex grinds, mostly because of Buzzbait's enthusiasm for them. I'm going to have to buy a convex ground knife soon.
Edited: I just re-read Cliff's last post and I think it answered my questions as well, which is that you do strop in sections. If my understanding is incorrect, please let me know.
I'm fascinated by convex grinds, mostly because of Buzzbait's enthusiasm for them. I'm going to have to buy a convex ground knife soon.
Edited: I just re-read Cliff's last post and I think it answered my questions as well, which is that you do strop in sections. If my understanding is incorrect, please let me know.
Cliff Stamp
BANNED
- Joined
- Oct 5, 1998
- Messages
- 17,562
If the edge has a strong belly, position the hone so it is perpendicular to one part and sharpen it and then repeat. On axes I sharpen with ~one inch wide waterstones, so I handle one inch wide sections at a time.
You can do the entire blade at once by pulling it sideways as you draw, and curving it to match the tip. If the strop is long compared to the blade, this will be very close to the same as keeping it perpendicular the whole time.
-Cliff
You can do the entire blade at once by pulling it sideways as you draw, and curving it to match the tip. If the strop is long compared to the blade, this will be very close to the same as keeping it perpendicular the whole time.
-Cliff
I picked up a Queen FB canoe to practice on when I read that thread. Haven't had time yet to even get more sandpaper though.
Soon
I hope
And good luck to you, it seems like a interesting and worthwhile project.
Ben
(if things work out I've got about 5 knives to do)
Walker, that particular Marbles has never been sharpened.
Generally, I don't do 1" sections at a time unless the knife is really dull. A dozen smooth strokes on fine grit will usually bring a knife of this size up to par if it hasn't been really dulled or chipped. I sharpen about half the blade with a stroke and then catch the other half. The strokes are pull strokes, moving the edge generally in the direction of the spine but with a little motion perpendicular to the hone as well.
After sharpening, I slip in a piece of leather and strop.
The hone is designed for field carry but it's easy to clamp it into a vise and use. I'm working on a small wooden model. This would be a single block of wood with some mousepad glued on and a slit cut in each end at an angle. Hopefully this will provide enough friction to retain the sandpaper. BTW, rubber bands work pretty good too. I buy the big yellow kind sold for rubber band guns. Glue a piece of mousepad to a block of wood, cut your sandpaper and wrap a rubbber band around it to attach to a woodblock. I do this a lot for woodfinishing and it's handy if you want to use small sanding blocks. Ya just need smaller rubber bands.
For larger blades, drywall sanders and sanding blocks in general work well.
Generally, I don't do 1" sections at a time unless the knife is really dull. A dozen smooth strokes on fine grit will usually bring a knife of this size up to par if it hasn't been really dulled or chipped. I sharpen about half the blade with a stroke and then catch the other half. The strokes are pull strokes, moving the edge generally in the direction of the spine but with a little motion perpendicular to the hone as well.
After sharpening, I slip in a piece of leather and strop.
The hone is designed for field carry but it's easy to clamp it into a vise and use. I'm working on a small wooden model. This would be a single block of wood with some mousepad glued on and a slit cut in each end at an angle. Hopefully this will provide enough friction to retain the sandpaper. BTW, rubber bands work pretty good too. I buy the big yellow kind sold for rubber band guns. Glue a piece of mousepad to a block of wood, cut your sandpaper and wrap a rubbber band around it to attach to a woodblock. I do this a lot for woodfinishing and it's handy if you want to use small sanding blocks. Ya just need smaller rubber bands.
For larger blades, drywall sanders and sanding blocks in general work well.
Thanks misque. It's been a project I've hand on my mind for quite awhile and I had the aluminum stock and thumbscrews lying around for 6 mos but just never got around to implementing it. Actually once you get the materials, it's a snap to make, Takes a couple of hours. I have a bandsaw so that helps but there's nothing precision about it so a hacksaw works fine. Of course it helps to have a drill press to get straight holes and a sander of some sort to square the corners.
Geode, I've tried those sanding sponges and they work good but they are too pricey, imo. Make your own and save some dough. But you can cut them up, glue them to a block of wood and use them like I used the mouse pad above. BTW, a good way to attach a mouse pad is to use double sided carpet tape.
Geode, I've tried those sanding sponges and they work good but they are too pricey, imo. Make your own and save some dough. But you can cut them up, glue them to a block of wood and use them like I used the mouse pad above. BTW, a good way to attach a mouse pad is to use double sided carpet tape.
- Joined
- Oct 3, 1998
- Messages
- 4,842
I like Hoodoo's gadget, too. I took advantage of Handamerican's bladeforums discount and picked up one of their systems that allows both stropping, and sharpening of convex edges with abrasive papers. Though the solution is different, it's more or less a production version of Hoodoo's gadget. It's also more than you need to spend for either stropping or convex sharpening, but it works so nicely that I"m very pleased with it. www.handamerican.com
Joe
Joe