How "sharp" should a camp knife/chopper be?

[dsvirsky]

I finally had an opportunity to use my BK&T Magnum Camp, chopping a big weed out of my yard. No edge damage, but after chopping into the dirt/mulch, digging, and prying, some sharpening was in order. No problem there, but I'm not sure how to test the edge to be certain that it's sharp enough. Certainly, the tests I normally use with my folders -- filleting a business card, shaving, etc. -- don't seem appropriate.

Suggestions?

 

[Josh Feltman]

I always thought the magnum camp was more of a high-performance camp knife for food prep, slicing, etc, instead of a hard use chopper. Isn't the blade thinner than the other Beckers? For the use you are describing, something like the Brute or BK-9 might be more suitable. If you are going to be prying, digging etc, you'll probably want to stick with a nice utility edge. A thin, razor-sharp edge will quickly be blunted by such use. If it is sharp enough to perform the tasks you routinely perform with it, then it's sharp enough. If you are looking for some sort of test, I usually check my big blades by cutting some typing paper.
--Josh

 

[Greg Covington]

On that knife I would recommend maintaining the edge with Norton Fine India stone and keeping only so sharp as to freely cut typing paper.

 

[Jason Cutter]

I reckon its the same as the how-sharp-is-sharp question. You can take 2 approaches :-

1) Assume you know what your intended use of the knife is - get it sharp enough, and only enough so that it will do the job adequately. Rough stoned edge ...

2) Assume that the sharper the knife, the better, even if it allows the knife to perform in excess of its intended use. The concept here is that the knife is going to get blunter anyway, as you use it, so why not start as sharp as possible. Enough to pop hair like a straight razor ...

Remember that "Sharp" is a function of a combination of numerous factors, including but not exclusively - the degree of fine-ness at the edge, thickness of the bevel hehind the edge, the shape of the edge and the angle of the edge, the blade shape, primary bevel angle, blade length , width, thickness and even the WAY you use the knife affects the way the knife cuts.

A razor hair-popping edge is not necessarily going to cut fibrous materials well if you use a slashing cut, but will work well if you pushcut THROUGH the fibrous material.

You have to consider all these factors. Most often the best is a compromise. Of course on a field tool, a major issue is HOW LONG it takes for you to achieve the type of edge you want and whether the equipment is portable, available etc.

Sorry for the roundabout spiel. Jason.

 

[Gabe Newell]

Darn it. I was reading through this thread formulating a response when Jason goes and says everything I was going to say only more and better.

 

[Cliff Stamp]

Remember that "Sharp" is a function of a combination of numerous factors, including but not exclusively - the degree of fine-ness at the edge, thickness of the bevel hehind the edge, the shape of the edge and the angle of the edge, the blade shape, primary bevel angle, blade length , width, thickness and even the WAY you use the knife ...

This would describe "cutting ability", of which sharpness is one factor. The only thing which effects sharpness is the condition of the very edge, geometrical factors (angle thickness) control cutting ability as they influence how much force it takes to push material apart so that the blade can pass through it, sharpness dictates how much force is required to actually cut the material, and this is only of consequence at the very edge. The distinction between the two should be clear if you consider handle ergonomics. A blade with a poor grip can cut very poorly due to low security and/or comfort, but would you call it blunt? If the handle was reshaped to remove these problems would you call it "sharpening" the knife.

As for how sharp to get a rough camp knife, if you are hitting dirt and rocks on frequent occasion I would just leave the edge finished with whatever hone was used to shape the edge. Get the bevels to cleanly meet and forget about everything else, because no edge will stay sharp very long in the dirt. Of course if you like sharpening, or it is very east for you then take it all the way up to hair popping, it won't be more fragile, it will in fact be more durable, however it still won't be durable enough to dig in dirt for any length of time and still be sharp so its all a moot point.

In regards to cutting tests, the most sensible ones are to cut the types of things the blade will actually see in use, or something which behaves very similar to those materials.


-Cliff

 

[Daniel Koster]

25 degrees each side (micro bevel) on a medium stone ought to do it. No need to keep a beater scary sharp. Now, if all you were doing was cutting wood....yes, keep 'er sharpened....and often.

A good test for sharpness for this beater knife might be how many slices it takes to go through a 1" rope.

 

[Danbo]

I have yet to see a need for a knife to be much sharper than a red/fine DMT diamond stone will get it.

 

[dsvirsky]

In regards to cutting tests, the most sensible ones are to cut the types of things the blade will actually see in use, or something which behaves very similar to those materials.

If I had those things, I'd be out cutting them, instead of looking ways to test for appropriate sharpness. I bought the Magnum Camp last year after chopping some weeds down with my mid-tech Crowfoot (great knife, but too short and too light for the job). Basically, an excuse to buy a big knife, in as much as I don't camp or do any of those other outdoor things that would normally justify buying something like this. Let's face it, I allowed this weed to keep growing until it was big, just so that I'd have a reason to use this knife

A good test for sharpness for this beater knife might be how many slices it takes to go through a 1" rope.

Good idea, but first I'd need a baseline, wouldn't I? How many slices is too many?

Greg and Josh -- thanks for the typing paper suggestion.

 

[Cliff Stamp]

[rope]

How many slices is too many?

That would depend on how much force you put into the cut. You are also grossly testing blade geometry there not simply sharpness. With equal sharpness, I have seen results range from 6 lbs on a two inch draw, to over 200 lbs depending on how the blade was ground (with 3/8" hemp) . So this really doesn't test sharpness, mainly blade geometry.

Of course if you want cutting ability tested then it is a pretty decent test for that, realize of course that it is for shallow cutting, and do both push and draw cuts to get a decent overall perspective. The more blades you do it with, the better you will get an idea of a meaningful standard for quality performance.

-Cliff