make a bk2 convex using mouse and sandpaper method

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buyer5207

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Mar 30, 2010
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OK, I tried to do this forever and it's not working. How is con-vexing exactly suppose to be done? How do I know if a edge is totally convex!!!HELP

BTW using 100 grip sandpaper
 
There are some tutorials on here that are great but I can tell you right off the bat that you need to go finer then 100 grit sand paper. That's so rough that I think it might dull more then it sharpens.
 
The mousepad has give, so when you pull the knife, its will gently "curve" around the blade, giving it a convex edge.

Are you only trying convex the edge? Or the whole bevel?

These videos are great: http://www.knivesshipfree.com/pages.php?pID=4&CDpath=0

I like convex edges for larger, thicker kniver for their toughness. However, its my opinion that a v-edge cuts better, and I can get my v-edges sharper with stones that my convex edges with a belt sander.

I'd start with a 220 for the mousepad. With a belt sander, i usuallly started with a worn 80 grit paper (and lots of water for cooling).
 
Yeah, I think the key is to start low and move high. I started with a 300. When I noticed the bevel start disappearing I moved up to 600, then 800 but then I jumped to 1200, 1500 and 2000. By the time you get to 1500 it's all polishing and refining so that in the future you just need a strip of 2000 on your thigh to touch it up (LIGHT PRESSURE).

There was an article in The Backwoodsman a few months ago about this process but the author was using the edge of a table and/or a block of wood at the beginning to really "cut" down the bevel. Yeah, it's faster but if you're new to this method you could seriously blow a grind in a hurry with that kind of pressure.
 
OK guys...I'm trying a mouse pad with a lanky puck method because I don't have any higher grit sandpaper. So I did that and it's wicked sharp but how do I know if it's a convex edge????
 
Is the blade stripped? When you convex, the line at the change in the grind angle between the edge and the rest of the blade blurs and almost becomes no existent. I say almost because only a full convex grind doesn't have it
 
buyer5207 said:
OK guys...I'm trying a mouse pad with a lanky puck method because I don't have any higher grit sandpaper. So I did that and it's wicked sharp but how do I know if it's a convex edge????
Click to expand...

!!! How did you manage with a puck!? The idea of the mousepad is that it "flexes" slightly so that the sharpening medium "wraps around" the blade material making a curved bevel vs. a hard straight bevel.
 
I'm confused as to how you used a puck and mousepad. You need the spongy, soft give of the mousepad foam to get the nice rounded convex edge. using a hard, flat puck will only give you a flat edge, unless you have some pretty decent sharpening skills to roll the blade as you're sharpening, and maintain that for the entire edge, on both sides. Pics, and searching, will make this alot easier.
 
I simply put the puck on the mouse pad and pulled when sharpening...The edge is rounded on each side (a little more on one side than the other ) but yeah that's how I did it.

Maybe it was the 100 grit sandpaper last night that made the edge rounded but it was very dull till I used the puck...

I compared it to my bk7 (factory edge) and it looks different and my bk9 (regular sharpened on a diamond stone) and it looks different. It'd be hilarious if it was a concave edge.
 
The sandpaper is supposed to be ontop of the mouse pad, that way there is some give. A mousepad and a puck don't work together in the context of this method. Help yourself out and watch some tutorials and then try it again.
 
Concave would be like a hollow grind, so doubtful lol. Either way, putting a hard sharpening puck ontop of the mousepad sounds like the mousepad isnt doing anything in this equation. The reason you use sandPAPER on the mousepad, is so that it can sink into the foam a bit as you bring your blade along it. Not saying you can't do it using a hard stone, just saying that a stone and mousepad does not a convex edge make. The sharpening surface should have give, like an open belt sander. If you're sharpening just against the lansky puck, it sounds like you're just doing a normal, V edge. I could be wrong though, hard to tell without pics, and admiteddly I'm no Hatori Hanzo when it comes to sharpening.
 
I didn't use a mouse pad, I used a leather strop mounted on wood. Same action though. The leather gives enough to create a rounded sanding surface.

It sounds to me like you might be moving the blade at different angles while sanding. When I did it on my BK2, following this Virtuovice How-To vid, I laid the blade flat from where the bevel starts all the way down to the edge and kept it at that angle while moving it over the paper. The only time I deviated from that is when I was working on the last inch or so before the tip, at which point you do have to raise the angle a little to keep up with radius.

I started with 400 grit W/D only because that's the lowest grit I had on hand. I don't think your problem is the 100 grit, as long as you're using higher grits to finish with. I might've missed it if you already said 100 is all you're using. Took me a long time for the basic shaping with the 400 grit, but after that, the finishing went pretty quick. I think the highest I used was 1500, maybe only 1000. I'm completely happy with the "feel" of the edge, but I confess, I haven't done anything to test it since I polished/convexed it several weeks ago. But it came out looking great, and it feels sharper than the out-of-the-box edge.

DSCF3711.jpg
 
IMHO, i feel you would be much better off starting with a smaller blade & convexing that first. The BK2 was a challenge for me as well. It still gets sharper everytime I have another go at it. Look back 10 or or 20 pages here when you get the chance, or use the search if you can. I started with 400, 600, 1000, 1500, 2000, 2500. I still do not have my BK2 convexed properly.
 
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