BK-2 sharpening (high polish = bad?)

K

killa_concept

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May 19, 2009
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Well I got my BK-2 awhile ago and after messing with it for awhile, the edge got a bit dull so I decided to sharpen it. I sharpened it the same way i sharpen my less meaty pocket knives and kitchen knives - 200, 400, then 1000 grit flat water stones followed by a stropping on a leather belt - it shaved hair with ease, could whittle a single strand of hair, and had a mirror finish. The second I took it out to baton and do a bit of wood work, it seemed to not work very well and lost it's edge fairly quickly. I kept the same factory angle (20 degrees on both sides I believe) and was under the impression that a higher polished blade was always better...

I've never really had a knife kept around for hacking through wood, so here's my question: is a highly polished edge more suited for kitchen work (meat/vegies), and not meant for harder tasks like batoning through/carving up wood? Would it perform better if I just sharpened it to 200grit then stropped it?
 
I would suggest sharpening to 200 and then stropping like you say. Going all the way to 1000 just to baton through wood will ruin that edge lickety split. Using a lubricant like WD-40 on the blade while you baton will help you move through the grain with ease, but it still won't save your edge.

One thing to think about in comparison is an axe edge: Not very sharp, flat grind wedge shape, and large sharpening angle. If an axe edge angle were 20 degrees, the first time you don't hit that wood straight on will likely snap it/dent it/chip it and otherwise destroy it. Now I know using an axe and batoning a knife through wood logs are two separate things, but you are technically using a knife to do an axe/hatchet's job.
That's my 2 cents anyway. Just a suggestion.
 
Most of the guys over on Wilderness & Survival Skills would tell you to convex the edge it you are going to be chopping. You can still get a keen edge that will hold for a long time.
 
chewbacca said:
Most of the guys over on Wilderness & Survival Skills would tell you to convex the edge it you are going to be chopping. You can still get a keen edge that will hold for a long time.
Click to expand...

Yes. I've only recently (in the last couple of years) come to believe in the qualities and advantages of the convex edge; largely in part due to what I had read in the Wilderness & Survival Skills forum. As such, I have convexed my BK-11, BK-2 and BK-7...and most all of my outdoor knives except my scandi's.

I'm of the opinion that having a high polished edge can aid in reducing friction going through different materials; at least it can't hurt. When you convex an edge, it gets pretty polished anyway. Regardless, it is more about the grind than the polish. I've found the convex edges are much more durable; especially on my axes and machetes. The downside is that they have a geometry not suited as well as other grinds to slicing. Some believe that to a fault, because I can tell you, you can get a convex edge to slice like a razor as long as the thickness of the blade is not too much. For example, a 1/8th inch convexed knife will slice a tomato much better than a thick convexed axe, but you could still do it with an axe.
 
My recommendation is convex edge, much more durable for field use.

Yes, the highly polished edge will last longer, the micro chipping is much less than with coarser stoned edge, the kitchen knife guys have this well documented.

Did the edge fold or crumble with the wood chopping? Use a 10x eye loop and examine the edge under magnification.

We sometimes see a wire edge formed when sharpening that initially appears very sharp and when used, will fold over and very quickly make the knife dull again. This can also be observed with the 10x eye loop.

Durability is more about edge geometry and removing the wire edge than exact steel alloy and Rc hardness.

Regards,
FK
 
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