Convex Blade Sharpening in the Field

[Pandabean]

I have a convex bladed knife and I know how to sharpen it at home using a mouse mat and W&D paper. But I was wondering how you would do this in the field? Do you take your mousemat and paper with you or do have a simpler method?

I think in the sticky above it was mentioned using a block of wood with a mouse mat and a way of fixing the W&D paper to it, although I do not know if this is a "just for home solution".

Edit - Is it also better to use a loose strop rather than one glued to a piece of wood for a convex blade?

 

[Xunil]

That's some big questions, and I'd suggest we make the distinction here between sharpening and stropping.

Sharpening (re-establishing the edge) should be done infrequently, as and when the edge reaches the point where it requires it or if it becomes damaged. Stropping should be done regularly, and unless you are unlucky enough to damage your blade while roaming around the great outdoors you should be more concerned about a portable strop.

Stones should be seldom used.

If you strop often it is possible to go weeks or even months without having to go back to stones (or abrasives mounted on boards, mouse-mats or whatever).

Most people let the edge go far too far before paying any attention to it and, as a result, they have to do back to stones/abrasives.

Stropping can be done on a standard leather belt without polishing compound, but I like to carry a small strop about a foot or so long with anything from diamond paste to Solvol Autosol chrome polish. If you use a loose strop just be careful to stop the angle of the leather as it flexes under pressure from rolling the edge too much, otherwise you will have to start all over.

If you carry billy cans and any pans you can always sit with the strop held across the flat base and simply gently slide your knife over it.

When I bowhunt in Canada I made a quiver where the strap doubles back on itself - if you release the strap from its fastener it is pre-loaded with diamond compound and I make it part of my evening camp chores to go over my knives and broadheads each night. It can be quite relaxing in fact.

Half a dozen strops on each side of a properly prepared edge and it's fettled. Quick, light, portable, easy, but practice beforehand so you don't roll the edge.

A small diamond/ceramic stone can be a lightweight and useful addition to you pack, just in case you ding the edge and need to do more radical work to it.

In summary, strop (correctly) often and sharpen on stones or abrasives infrequently.

How you do it is largely a matter of choice.

 

[MSkiba]

Yup I would just strop.

Ive noticed a big difference in stropping with different types of leather. A nice thick 3.5mm rough leather works best for me and a lot better than thinner leather. Since i got this It seems I dont use my stones (or mousepad + sandpaper) anymore as the stropping does such a good job

 

[Pandabean]

Thanks guys I was a bit rushed when I wrote the original post so apologies if I was unclear during it.

3mm thick leather I have plenty of so it isnt a problem for a strop, in fact I think I have slightly thicker stuff that is an offcut from a belt I made.

When I tried stropping on the wooden baton which has a long piece of leather and Autosol on it I found that I had dulled it slightly and the edge wasn't coming back. I guess this would be a case of holding it at the wrong angle, if that is possible on a convex blade? The technique is from a video on youtube (not the best of sources at times) and it seemed pretty easy to follow.

One thing that is confusing me a the moment is if you have the leather strop on its own and tied at one end to something and you run your knife a few times on that, it can result in rolling the edge but doing it on a solid surface doesnt? This seems a bit different to how you would use the W&D paper for sharpening it. Is there a reason for that? Hope that makes sense

 

[Xunil]

The wet and dry method establishes the general geometry of the edge - stropping polishes that edge itself and makes it far more aggressive.

If you are learning the technique you should get a permanent marker and mark all along the edge about 3 or 4mm or so high. On your first trip across the strop check the blade and you will see where the metal has been polished. Adjust your angle accordingly.

For almost all outdoors knives I stop at either 400 or 600 grit stones/belts/abrasives and go straight to the strop. This type of edge is quick to establish and, once stropped, is avery aggressive on meat and food stuff, and I have always argued that most outdoors knife use is in food prep.

More people seem to be thinking along the lines of their bushcraft knife being a dedicated woodworking tool and, if you are one of them, it makes sense to go higher in your abrasive grits before heading to the strop.

I would take the 600 grit and then strop every time over the multiple grade wet stone/Japanese wet stone and then strop method used by some. This is just my opinion based entirely on what suits me though.

Try a marker pen to see where you are actually stropping and you should easily be able to adjust your technique.

If you use the method I suggested for holding the strop flat over the bottom/side of a billy can or skillet you don't need to worry about the angle variables of a hand tensioned strop, which requires a different technique again.

Get to grips with one first and then move on to the other, using the same methods to gauge where on the blade you are working.

 

[rik_uk3]

Pay a tenner for

http://www.bladetech.co.uk/blade_tech.html they work, no flaffing about, they just work.

 

[ged]

Pay a tenner for

http://www.bladetech.co.uk/blade_tech.html they work, no flaffing about, they just work.

Do they work on a convexed edge Richard?

 

[Xunil]

Doesn't a device like that defeat the entire purpose of a convex grind ?

The whole point of the convex is not to have a secondary bevel; the convex extends right to the cutting edge, giving a sharp but very well supported edge.

I know some folks prefer a secondary bevel on Scandi, flat, hollow, convex etc but the intention behind the convex is to maintain the shape right to the edge and not give it a secondary bevel.

If you want a simple method of sharpening then I guess it answers that need, but I don't think it gives optimal results.

If you decide to use one make sure you apply very gentle pressure during sharpening - I know a lot of folks who have tried these (and similar devices) who end up pulling chips out of the edge of their knife when sharpening with anything more than gentle pressure.

A mate of mine used one of these on his brand new chefs knives and the first one he did chipped out horribly - I flattened off the edge and reground it for him, but in mere seconds and in two strokes the sharpener chipped out the edge in 7 different places - I had to remove a good 1 - 2mm from the entire edge which equates to a lot of normal use/sharpening, so the exercise effectively cost him months of normal wear and tear in one fell swoop.

See how the chips are all of a similar shape, going with the direction the sharpener and knife were pulled in relation to one another.

I think devices like this have their place, certainly, but if we put this into context I would expect to set the edge up on, say, a Bark River Knife & Tool or Fallkniven convex blade and head out for a week in the wilds without having to touch the edge at all. Knife use tends to be quite minimal and generally fairly lightweight, provided you have and use the right selection of tools for the job.

If the heavy work is done with a hatchet, saw or machete then your knife is usually used for minor trimming jobs, food prep, perhaps pegs or triggers for traps and similar stuff. Nothing on that list should challenge the edge of a good knife over many days of use.

Anyway, like I say, I feel that devices such as these have their place but they are no substitute for knowing how (and when) to sharpen properly and particularly on Scandi and convex grinds they defeat the object by introducing a secondary bevel. Just an opinion, for what it's worth.

 

[John Fenna]

For convex edges I would just strop, but using wet and dry on a mousemat, followed by flat leather stropping to polish the very edge...it is all down to angle realy. In the field I strop on the inside of a leather belt...if I realy need to address the edge at all. I also carry a tiy diamond stone to deal with any big dings...
Blade-tecs are OK but you need to be gentle and I would not use them on a convex

 

[Pandabean]

Thanks for the tips guys, Im just use to sharpening my cheap mora, took a while to learn that properly but I think I have it with that. Its just a bit different going to a convex blade when used to another way.

One bad thing about sharpening properly is you suddenly have a problem with hair loss on your limbs.

 

[Dark Horse Dave]

Have a look here: http://www.turleyknives.com/sharpeningaconvexedge.htm

Quite interesting:; portable & easy too

 

[Xunil]

... One bad thing about sharpening properly is you suddenly have a problem with hair loss on your limbs.

Request the use of someone else's.

It's a great conversation stopper in the right social circumstances...

"Stop wriggling. Hold still..."

"This won't hurt - honest"

"Trust me, I'm a bushcrafter"

 

[rg598]

I just use a regular sharpening stone and sharpen it the same way you would an axe. This is the method I use.