Convex edge Sharpening System

I kindly agree about the mousepads having too much "give". I did want a stiffer backing for the 2000 grit, but as I work these things, I am going to make a board with leather backings for the 800 and 1000 too.

I agree with Mongo too. Each Barkie has it's "own" angle for the best edge. It's taken me time and mistakes to realize that. My Highland Special likes a very high angle and, yes, the mini-Canadian likes a low one.
 
STAGE 2 said:
Here's a stupid question. Are the mouse pads that you guys use just the standard thickness? The reason I ask is because looking at mine it doesn't feel like it has enough give to contour to the blade, especially with the only moderate pressure that you're supposed to use.

Am I missing something?
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You're not missing anything, I don;t think. I've seen these new mousepads that aren't much thicker than the thin cardboard of a file folder. THe more I think about it, the more I think they might work ok....like everyone says, we don;t want too much cushion.

The mousepads in the pic above though is the old standard. Pretty thick...almost exactly 1/8". But, then again.....I'm using such light pressure that I'm not sure if the extra cushion affects it much.
 
How do you convex the belly of the blade when using hard benchstones instead of mouse pads and sandpaper?
 
Easyrider said:
How do you convex the belly of the blade when using hard benchstones instead of mouse pads and sandpaper?
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You can increase the angle during the sharpening stroke (for example start the stroke at 9 degrees and finish at 14).

Or even simpler just sharpen using different angles creating multiple bevels - ie. convex. Unless you can hold your angle identically for each stroke, there is always some convexity created with freehand sharpening.
 
Thanks for the post, StretchNM. I've recently gotten several convex edged knives–including two Bark Rivers–and have been pondering this very thing. The photos are very helpful. As was the post about just catching the edge, then holding that angle on the draw.
I suppose it's best to use pieces of strop or pad suited to the length of the blade, but do you think it makes much difference starting and stopping along the blade when the blade's longer than the strop or pad?
Thanks.
 
Many of my blades are longer than the strop is wide....longer than the wet/dry setups too. Sometimes what I'll do is sharpen just the lower portion of the blade - from the hilt to the belly. I'll go maybe 10 or 15 or 20 strokes, flip it over, do the same on the other side. Then I'll start and do the same sequence on the portion of the blade from belly to tip.

Other times I just do the whole edge, regardless how long the blade is. As I'm stropping, starting near the hilt, I'm also slowly drawing the blade away from the strop, so the belly to tip gets some honing as I approach the end of the stroke. Does that make sense?
 
Yep, just pulling the blade down the strop at a hard angle, sounds like. Thanks!
 
I have a question. So, I like to keep things simple and small when backpacking. In doing so, what has worked - for my current setup - is a DMT mini-sharpener attached to my Mora sheath using improvised 'ranger bands.' However, I just pulled the trigger an a Fallkniven F1 and am now wondering what my 'travelling' system would be for it. I read the above "leather and sandpaper" but that seems like it would be a little bulky, and not nearly as easy to employ in the field as the DMT. (How much, and the size of each, I suppose, would determine this...) Is that the only choice, or, could a guy like me use the flat stone in the field, in a pinch, and use the leather and sandpaper 'convex' set up at home? Or, is this a no-no on a convex blade...?

If you haven't guessed, this F1 would be my first convex. I am, however, fairly proficient at sharpening. (Read: the guy who sharpens all his family, friends and co-workers knives for the price of a soda pop...except 'the first one's free.') Have always been of the school of thought, 'if you can't shapen then, why own them.

Anyway, I appreciate any thoughts.


-Mark
 
You can use an ordinary flat stone to create a convex edge. Same way you round a piece of metal with a bastard file. I have an opinel I convexed. I place it flat on the far-side of the stone, edge facing away from me, and as I pull the knife towards me, I lift it up till around 10 degrees to created a rounded bevel from flat side of knife to edge. Same for the other side.
I hope this helps.
 
fdd19 said:
will 600 grit produce a razor edge on 400 series stainless steels?
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Yes, I have an old Cold Steel Ultra laock that I bought about 12 years ago and really screwed up the edge trying to hand sharpen it. Because it was so mutilated it languished in a drawer for a long time. When I got my Barkies and Fallkniven I thought to try and ressurect the knife by convexing the messy grinds away. It worked extremely well and it came out hair popping sharp. IIRC the Cold Steel was 420 with some uber cryo heat treat :jerkit: Anyway, it works and its my go to knife for jobs I wouldnt consider using my other knives for, like cutting roof tar strips ;)
 
I'm still new to all this... I convexed a couple practice knives (originally beveled) last night. I used 320 followed by 400 grit wet/dry sandpaper on a 6" x 6" x 1/8" piece of rubber that I found in a hardware store. I used pretty light pressure at a very shallow angle (about 13 degrees)... it worked OK, but none of this scary sharp stuff. I'm sure I need more practice. I didn't move on to the 600 or 1500 that I'd picked up, because I've read that you should be able to get it extremely sharp with most any grit, so I figured that I was doing something wrong.

In your setup, which direction are you stroking? For instance, on the three setups in your picture that are aligned "horizontally", would you stroke the blade from right to left, or top to bottom (assuming you are sharpening, say, an 8" chef's knife)? I assume you want as long a stroke as you have paper?

Also, how many uses would you expect to get from a piece of sandpaper (if you are changing a beveled edge to convex)? I'm sure it depends on the hardness of the blade, but (ballpark) how many strokes are we talking... 10, 20, 50, 100, 500??
 
I find myself going back and forth between 8-9oz leather and a mousepad. I don't know exactly why, but I seem to get better results with one or the other depending on the individual knife. For sandpaper, I use 320 for small chips or when changing an edge from flat bevels to convex. After that, I usually go 600, 800, 1000, and 1500, followed by the strop, which is also 8-9oz leather, smooth side up with compound rubbed into it.

As to Dain's question, it's hard to say exactly, and it does depend on the steel, hardness, size of blade, and width/angle of the original bevel, but it sometimes takes quite a number of strokes to go from bevel to convex. The best way I've found is 320 grit on leather, since it removes metal fairly quickly and you can apply more pressure to the leather backing.

Another personal observation about convexing: when you first start doing it, especially if you try the mousepad method first, leather backing feels very hard and unyielding, so it doesn't really "feel" like it's going to work. I stuck with the mousepad exclusively for a long while because of this, but once you give leather a try, you find that it does actually work very well, and that it gives more consistent results (at least for me).
 
I agree more and more that leather backing is very good.

I stroke the length of the sandpaper....long ways. Another thing I do is hold the wet/dry board in my left hand, and use my right hand to strop the knife. This way, I can adjust the angle ever-so-slightly as I'm working. This comes into play alot because I've found the angle of the grind is slightly different between the hilt and belly than it is from the belly to tip.

I push the knife away from me for 10, 15, or 20 strokes. Then I flip the blade over and pull the knife toward me for the same number of strokes. For final passes on the 2000 grit, I'll usually flip the blade every other stroke....with *very* light pressure.
 
I'm another one who does all my convex sharpening on a bench stone. For me it is much easier than the soft backing and sandpaper. I think most people would be very surprised at how easy it really is to do on stones.
 
Sharkmeat said:
I have a question. So, I like to keep things simple and small when backpacking. In doing so, what has worked - for my current setup - is a DMT mini-sharpener attached to my Mora sheath using improvised 'ranger bands.' However, I just pulled the trigger an a Fallkniven F1 and am now wondering what my 'travelling' system would be for it. I read the above "leather and sandpaper" but that seems like it would be a little bulky, and not nearly as easy to employ in the field as the DMT. (How much, and the size of each, I suppose, would determine this...) Is that the only choice, or, could a guy like me use the flat stone in the field, in a pinch, and use the leather and sandpaper 'convex' set up at home? Or, is this a no-no on a convex blade...?

If you haven't guessed, this F1 would be my first convex. I am, however, fairly proficient at sharpening. (Read: the guy who sharpens all his family, friends and co-workers knives for the price of a soda pop...except 'the first one's free.') Have always been of the school of thought, 'if you can't shapen then, why own them.

Anyway, I appreciate any thoughts.


-Mark
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I have read that for field convexing, some guys carry some sandpaper and lay it on their thigh for the backing.
 
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