Convex edge sharpening

Trail Edge

Trail Edge

BANNED
Joined
Apr 23, 2011
Messages
936
I'm about to get my first convex edge knife and I am curious on how to sharpen it. I have the Spyderco Sharpmaker, but I can scarcely remember something about a mouse pad and sand paper. Thanks for any input.:thumbup:
 
If it comes sharp, than you'll only really need to strop it to maintain its sharpness if its used normally. However, if the edge really gets dull, you might want to use 600 to repair the edge, and then refine/polish further with increasing grits of sandpaper. If you're using the mousepad method, just lay the sandpaper on it and make the same motion with the blade (edge trailing) as you would when stropping.

I recommend getting a belt sander, it does the same thing except infinitely quicker. I have the Work Sharp and I use it on everything from small folders to kukri's. You just can't beat the efficiency.
 
Misanthropia said:
If it comes sharp, than you'll only really need to strop it to maintain its sharpness if its used normally. However, if the edge really gets dull, you might want to use 600 to repair the edge, and then refine/polish further with increasing grits of sandpaper. If you're using the mousepad method, just lay the sandpaper on it and make the same motion with the blade (edge trailing) as you would when stropping.

I recommend getting a belt sander, it does the same thing except infinitely quicker. I have the Work Sharp and I use it on everything from small folders to kukri's. You just can't beat the efficiency.
Click to expand...

Thanks, Ive heard the blackjacks come sharp. That belt sander sounds nice!
 
Just another thing, if the grind angle is somewhat obtuse or the knife is really thick, make sure to lift the spine up a bit to make sure you're contacting the edge. 2500 grit should give you pretty close to a mirror finish on the edge, using a higher grind on a belt sander will get you all the way there.
 
Have a look @ knivesshipfree!!
They have posted an entire 12 video convex sharpening tutorial!!

Good stuff
 
Komitadjie said:
^ That. KSF's video series is one of the most comprehensive I've seen.

You can find it HERE.
Click to expand...
Thanks guys. Here is a picture of the knife
BlackJack14HaloAttackPics002.jpg
 
Misanthropia said:
I recommend getting a belt sander, it does the same thing except infinitely quicker. I have the Work Sharp and I use it on everything from small folders to kukri's. You just can't beat the efficiency.
Click to expand...

The Work Sharp is a great belt sander sharpener -
I would second that recommendation -
Review - Work Sharp (belt grinder) Knife Sharpener

However just a little clarification -
Convex edges can be:
"Zero bevel" convex - this means the edge merges continuously/seamlessly into the blade face.
or
there is a visible separate bevel - but that bevel is convex to the edge -
this may seem nit-picky/pedantic -
but a lot of regular plain bevel edges knives when sharpened on a belt sander, like the Work Sharp, are like this.

To achieve a zero bevel convex edge - would mean grinding/reducing the entire blade face to the edge -
(as opposed to sharpening only the edge and bevel).

To maintain a zero bevel convex edge for most of us normally means using sandpaper & mouse pad method -
the Work Sharp would probably work - but there is a slight possibility that it may result in a separate bevel being ground in.

Having said that - if one looks at one of the most famous and prevalent zero bevel convex edge knives - the legendary Opinel - on close examination one can see a very fine micro-bevel - so the Opinel is zero bevel - but with a very thin microbevel
Please see:
Sticky Thread: Microbevels

If one can live with that - for any light touch ups -
then any V-hone crock-stick sharpener (like the Spyderco SharpMaker) will do to maintain that.

Hope that helps, and not too pedantic :o

--
Vincent

http://picasaweb.com/UnknownVincent?showall=true
http://UnknownVincent.Shutterfly.com
http://UnknownVT.Shutterfly.com
http://UnknownVT.multiply.com/photos
 
i use a belt sander to work up a burr on a convex edge and remove the burr with the slotted paper wheel. you can also maintain an edge with the wheel the same as stropping but faster. i can take any of my knives that i make and touch them up with just a few passes. the same with a v edge.
 
Komitadjie said:
Dang, that's a good-looking Blackjack. :)
Click to expand...

Thanks, I just got it in.

UnknownVT said:
The Work Sharp is a great belt sander sharpener -
I would second that recommendation -
Review - Work Sharp (belt grinder) Knife Sharpener

However just a little clarification -
Convex edges can be:
"Zero bevel" convex - this means the edge merges continuously/seamlessly into the blade face.
or
there is a visible separate bevel - but that bevel is convex to the edge -
this may seem nit-picky/pedantic -
but a lot of regular plain bevel edges knives when sharpened on a belt sander, like the Work Sharp, are like this.

To achieve a zero bevel convex edge - would mean grinding/reducing the entire blade face to the edge -
(as opposed to sharpening only the edge and bevel).

To maintain a zero bevel convex edge for most of us normally means using sandpaper & mouse pad method -
the Work Sharp would probably work - but there is a slight possibility that it may result in a separate bevel being ground in.

Having said that - if one looks at one of the most famous and prevalent zero bevel convex edge knives - the legendary Opinel - on close examination one can see a very fine micro-bevel - so the Opinel is zero bevel - but with a very thin microbevel
Please see:
Sticky Thread: Microbevels

If one can live with that - for any light touch ups -
then any V-hone crock-stick sharpener (like the Spyderco SharpMaker) will do to maintain that.

Hope that helps, and not too pedantic :o

--
Vincent

http://picasaweb.com/UnknownVincent?showall=true
http://UnknownVincent.Shutterfly.com
http://UnknownVT.Shutterfly.com
http://UnknownVT.multiply.com/photos
Click to expand...

I miss my shop and shop equipment. I’m doing the “rent a small place and going college full time” thing again, but I’ll rank a belt sander up there with, or maybe before a compressor when I get my shop back.


richard j said:
i use a belt sander to work up a burr on a convex edge and remove the burr with the slotted paper wheel. you can also maintain an edge with the wheel the same as stropping but faster. i can take any of my knives that i make and touch them up with just a few passes. the same with a v edge.
Click to expand...

Sounds nice! I’ll be looking into that in the future. I have a small economy strop that I just used to put a new edge on my BlackJack this morning, and it is noticeably sharper (the knife is a keeper).
I think I’ll be asking advice on what type of substantial strop would be best to get next.
 
I am digging up this old thread because it seems the closest fit.

I have a new Bark River mini Bushcrafter. It came sharp but not really sharp. I can't live with that, this is my sharp Bushcraft knife.

I am not new to sharpening but convex is new to me.

My problem is that it seems there is a strong bevel on one side of the blade. How do I go about working the bevel off? Do I move the contract back towards the spine?

The better side was 0 bevel in the middle and a bit of bevel at both ends, so it looks like just working that edge will correct it.

Thanks!
 
BDay said:
I am digging up this old thread because it seems the closest fit.

I have a new Bark River mini Bushcrafter. It came sharp but not really sharp. I can't live with that, this is my sharp Bushcraft knife.

I am not new to sharpening but convex is new to me.

My problem is that it seems there is a strong bevel on one side of the blade. How do I go about working the bevel off? Do I move the contract back towards the spine?

The better side was 0 bevel in the middle and a bit of bevel at both ends, so it looks like just working that edge will correct it.

Thanks!
Click to expand...

I honestly would return the knife or send it back to Bark River to have them regrind it, their knives are supposed to come with a zero convex grind. Shouldn't be a bevel at all from what I understand.
 
BDay said:
I am digging up this old thread because it seems the closest fit.

I have a new Bark River mini Bushcrafter. It came sharp but not really sharp. I can't live with that, this is my sharp Bushcraft knife.

I am not new to sharpening but convex is new to me.

My problem is that it seems there is a strong bevel on one side of the blade. How do I go about working the bevel off? Do I move the contract back towards the spine?

The better side was 0 bevel in the middle and a bit of bevel at both ends, so it looks like just working that edge will correct it.

Thanks!
Click to expand...

You should work it well back up the curve to where it meets the shoulder. This might take longer then you'd think, depending on how pronounced the bevel is you're trying to eliminate. Sending it back is a real option, this is not a Condor mini where the cost of shipping both ways might exceed the value of the knife, and grinding off a bunch of steel to correct the problem might erode some of its useful life.

Any time one touches up a convex/scandivex, it pays to do the entire primary grind, and preferably to work from the shoulder to the edge.
 
I touch up my convex edges on sharpmaker, and when almost invisible micro edge gets bigger, use a beltsander, stone, or sandpaper.Small microbevel on fully convexed blade is much easier to maintain and the performance is the same as on zero edge.
 
Thanks, all of that makes sense.

From the 30 minutes I spent working I can see that it could be a long task by hand. When I get a chance I'll put some marker on and see what it takes to move the point of ware back to the shoulder.

Maybe at that point I may send it back.
 
BDay said:
Thanks, all of that makes sense.

From the 30 minutes I spent working I can see that it could be a long task by hand. When I get a chance I'll put some marker on and see what it takes to move the point of ware back to the shoulder.

Maybe at that point I may send it back.
Click to expand...

Making a bunch of lines from shoulder to edge is a good way to keep track of what's going on. End of the day, you'll have to learn how to do this anyway for long term maintenance, but it sounds like a tough way to get your feet wet.

The work itself is pretty straightforward, the challenge is to make it cosmetically nice as well. Have to start with a reasonably coarse grit or it will take forever.
 
HeavyHanded said:
Making a bunch of lines from shoulder to edge is a good way to keep track of what's going on.
Click to expand...

That is what I do too. I now use my belt sander on the flat platen to thin out the blades without ever touching the edge/apex to a point where I like the profile, then I blend in the bevels with the belt backed by a felt pad (again without touching the edge), then I do the last steps by hand.
 
I was thinking I could do the profile with my edge pro, as a series of bevels, then finish by hand. I would have to mess around with the marker a while before starting that. You can't put metal back.
 
I spent about 4 hours with 220 grit and got the profile almost looking good, just one place near the tip that I messed up by going off the pad and increasing the angle. I thought it might get sharp so I polished it up. Nope!

It now has a razor sharp 17 degree bevel.

In retrospect, I could see that there was a little edge that was not getting sharpened. The angle was very fine, below 15 by a good bit, but I was not getting the edge.

For me I think the convex edge is just too vague.

I will mess around when it a bit more when I have to sharpen my bark river Scalpel; that came sharp.
 
You must log in or register to reply here.
Back
Top