Can I Put a Convex Edge on a Benchmade 806D2?

Thanks for the insight cliff.
I work in the leather industry and most of my cutting involves cattlehides in all stages from raw to fully tanned.
In 35 years of daily knife use, I've found nothing that works better for me than Dozier's hollow ground D2. Now I have asked him to make me a convex grind version of his folding hunter, which is my daily use knife. I'll give you guys a comparison report when I get it.
 
Seeing that you are working with leather, I’ll think you’ll really like Bob’s convex grind. I’ve played with Bob’s convex grinds on tanned leather, and the push cuts were effortless. You could literally hold the knife still, and move the leather through the cut. I haven’t played with any leather that’s thicker than 3/16”, or raw hide, but the thin tanned stuff cuts easily with the convex grind.
 
Thought I might add some pics to this thread to help out a bit.

convex1.gif



convex2.gif



On left: semi-flat grind (slightly hollow)
Middle: desired convex grind
On right: overlay of the 2 grinds - showing the material that needs to be removed.
 
csbjr :

[leather]

I've found nothing that works better for me than Dozier's hollow ground D2.
Click to expand...

Try a knife with a minimal edge geometry with a high hollow relif, sharpen from the edge to the spine.

-Cliff
 
Cliff,
Not sure I am clear on your last statement. Do you mean high convex grind? Can't see how I would sharpen a High hollow grind from spine to edge.
Dozier's knives are the best I have found for general use around a tannery. All have relatively wide, thin blades with a very high hollow grind. I am having him make me a convex blade the same size and shape as the folder I have been using for about three years. I am anxious to be convinced that convex is better. What a sweet knife it will be that can out perform what I have.

But another observation/Question.
Dozier's D2 responds beautifully to occasional swipes on a steel. Perionically, but not often, I resharpen on a fine diamond hone.
The question is this: Can I expect the same degree of ease of blade maintanence on a convex grind considering the same steel/heat treat?
 
csbjr :

Can't see how I Can't see how I could sharpen a High hollow grind from spine to edge.
Click to expand...

You lay it flat on the stone.

Yes, you can steel convex ground blades, stropping is more inline with their nature however.

Provided the edge isn't damage, but just a little worn or rolled / bent, it can usually be restored with one or two passes per side on a suitable abrasive, which can be a flat benchstone if you have the skill, or some sandpaper on something soft to allow the curvature to be matched automatically.

You can improve the performance of the knife you have now by simply lowering the edge angle, or cutting a relief. How much of a gain you can see depends on how thick Dozier leaves his edges and how obtuse they are.

If the edges are 0.005" to 0.010" thick, a relief won't do you any good, but you might still benefit from the edge angle dropping assuming it is 15 degrees per side or more.

-Cliff
 
Maintaining a convex grind takes a little time to get used to, but I've found it to be even easier in the long run. For the occasional touch-up, I just strop the blade on a piece of adhesive backed wet/dry paper. Depending on what degree of polish you like on your blade, the paper could reasonably range from 400 grit to 2500 grit. You could also use a loaded leather strop, assuming that you have a piece of leather lying around somewhere. ;)
 
Thanks for the clarification Cliff.
I guess I have blundered into a good combination over the years.
Dont know the blade thickness at the edge, but with the spine about 1/16 inch off the stone, I am guessing an angle of about 10-12 degrees. Even at that angle, the edge bevel is very thin.

Thanks for the input.

Chuck B.
 
Buzz,
I see more leather daily than most see in a lifetime. Shouldn't be a problem.
 
Have you tried sharpening it flat on the stone. The increase in cutting ability should be noticable.

-Cliff
 
Yes. Problem then becomes wire edge and fragility (is that a word?). Some of the cutting is heavy duty. Removing tails and other body parts is tough on extremely fine edges.

Don't take my initial comments wrong. Dozier's knives work so well for me, I cant seem to find better. I guess I just don't want to believe I have already found the perfect knife. I need an excuse to keep looking.
 
In that case you would want to create a small secondary bevel to raise the cutting ability, which is pretty much what you have done. Are you seeing the edge deforming or chipping when you run flat to the stone?

If it is deforming you might be able to use that low an angle on a harder steel. You might also see a benefit in having a deeper hollow grind. This will reduce the force used on the cut and may act to stabilize the edge.

-Cliff
 
I am way out of my depth here, but FWIW here are a couple observations about my Yari and 806D2. My 806D2 used to easily outcut my Yari in wood. I think that was because the 806D2 had a thinner blade and 30* secondary bevel and maybe a very slight 40* primary bevel (honestly, I can't recall--I might have just left it at 30* since it is D2).

The Yari had a wider 30* secondary bevel (due to its factory edge thickness) and a 40* primary bevel (I hope I'm using the terminology right).

After convexing the Yari, it cut better than the 806D2 in wood. It will be interesting to see what kind of gains, if any, I get out of convexing the 806D2. I hope I haven't thinned out the edge too much and compromised its durability. the convex "bevel" starts to roll toward the edge higher than the old flat bevel.

Great info! Thanks all :)
 
Originally posted by JDMSMBACPA
the convex "bevel" starts to roll toward the edge higher than the old flat bevel.
Click to expand...
Yes. This is normal.
 
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