Convex grind: AMAZING!

[akennedy73]

But, I now view any blade without a convex grind as "not a real knife." This is not an official opinion, just a personal amazement at the geometry of a convex grind.

I will never own a knife again that does not have this grind. It is stunning in its cutting power.

Personally, I'm not giving up on other grinds - why limit myself?

but you're right - convex is amazing in what it can do. i probably subconsciously handle convex blades differently - i didn't grow up with them, don't have much experience relative to flat and hollow grinds, and have too much respect for what they can do.

valiantco blades have convex grinds - swinging one of these is FUN! :thumbup:

 

[Blue Sky]

I was playing around with snap cuts through brown paper grocery bags, using the Fox River. It sliced through full length each time (the bag was freestanding, held only at one corner by me).

As it got close to my "holding hand," I laughed to myself - "What if I happened to hit my holding hand with the blade as I quickly sliced off pieces of bag?"

You know this now, but never ever put your body in harms way when swinging a sharpie. There was thread some time ago about a guy who was showing off how sharp his knife was by cutting free-falling tissue paper. Well, one time (the LAST time) he didn't let it fall far enough from his fingers before he swung. Needless to say, tissue paper wasn't the only thing that hit the floor that day.

 

[Liam Ryan]

I am with you on this one Liam Ryan... I thought about convexing every single blade I own. I got setup as soon as I got my F1. Got some pieces of plywood and being in lack of suitable mousepads I found some high density foam at home I use as a backing. I think it has as little give as using leather as a backing (I don't have to worry about rounding edges at all). I found some polishing compound (green chromiun and the red one) but I am having trouble finding a suitable piece of leather to make a strop.

I thought about convexing every blade I own but so far I just did it on a beat up Solingen stag handle knife I found cheap on ebay. I wanted to convex my RAT-7 (I even started a new thread HERE) but I am doing some testing with my kitchen knives first. I don't want to screw up my RAT-7. Being D2 is going to take a while.

Sketchbag suggested me knocking the shoulders off with a stone first, so I don't take two years convexing it with sandpaper. Your Lansky system will surely help here.

I have two BRKT knives on the way, they should be here anytime soon (Aurora and Canadian Camp) so I will tell you about it when I get to used them.

Mikel

My bark river micro slither was my first convex blade, it was SHARP! but also too small to really get any use out of, so it took my gossman PSK to really open my eyes, I could have split atoms with it.
I have since had an F1, and a bark river nebula and fox river. (I traded the first 2 cause the handles didn't suit me.)
I am working on my RAT RC4 right now, I used a small file to carefully round the shoulder, then some diamond paste and finally green CrO paste, seems to be working really well, the black coating actually helps get the angle just right, but it's gumming stuff up a bit.

 

[budd4766]

You guys are killin' me. I thought I was getting carried away trying to find old Old Timer stuff on Ebay...now you've got me drooling over just about everything else!

Where does it end???

 

[Brian Jones]

You know this now, but never ever put your body in harms way when swinging a sharpie. There was thread some time ago about a guy who was showing off how sharp his knife was by cutting free-falling tissue paper. Well, one time (the LAST time) he didn't let it fall far enough from his fingers before he swung. Needless to say, tissue paper wasn't the only thing that hit the floor that day.

I knew it before, but overconfidence and a couple Bass beers (probably mostly the Bass) = temporary stupidity.

 

[Mtn Hawk]

I'm no sharpening expert, but from what I've learned, read, and experienced the last few years, I think the key to a good edge is raising a burr so that you know the edge is as thin as possible and that the sides meet. It stands to reason that the thinner a knife edge, the easier and more deeply it will cut. Since many factory edges are thicker than they need to be, I wonder how much debate and confusion about edges is really due to the thickness of the edge, rather than about the type of edge.

After thinning, the edge can be left as it is, convexed, or a microbevel or two added, depending on how the knife is going to be used and how much edge durability is required. I haven't tested different edges to be sure, but intuitively I'd think a convex edge would be best for chopping wood and that a microbevelled edge would be best for more delicate chores such as carving and slicing, since there is less edge mass to be pushed through material than a convex edge. I don't think an edge with a microbevel or two is too far away from a convex edge, especially when the edge is thinned out to begin with.

 

[NoFair]

This

still fears this

Tendon made it mostly unharmed, but some nerves are severed and will take some time healing

Didn't feel the cut until it hit the bone.

Note to self; if something is falling check that it isn't the knife you just stropped before catching it

 

[Brian Jones]

LMAO, NoFair!

 

[texastonydobbs]

Ouchy.....

 

[NoFair]

LMAO, NoFair!

I actually still feel a slight tingle in my left index finger whenever I unsheathe the BRKT Northstar

Not been bitten badly by any of my knives since I was 5 so I guess it was about time

Sverre

 

[Lycosa]

CRAZEE stories!! My Woodland Spl. just arrived. That little blade is as sharp as my Hartsfield's and Leu's. Oh, my worst bite was by an 8ft. Siamese croc.

 

[Gossman Knives]

You sure can get a convex edge sharp as hell. I like the grind on 1/4" and 3/16" camp knives. They fly right though seasoned wood when batoning. It will also torque/twist around a knot without any problem on damage to the edge. The convex grind pushes material apart better.
Scott

 

[mindwip]

Yup. That's the nice part of stropping. You're moving away from the edge!

Sure tell me now! Needless to say i now use a diomand/ceramic plate and sanding block! let the knife cut that up all it wants, my fingers are much happyer

 

[Return of the J.D.]

I've tried every trick in the book and am still only able to keep a moderate edge on my convex blades. I've been patient without too much success.

One thing that has worked, however, is to dump the mousepad. The mousepad made it worse usually (I know, 'I'm pressing too hard and rounding the edge'. It still does it with a feather touch.). I just take some X grit sandpaper and lay it on a hardback book, then drag spine-first with the weight of the blade, at an angle where the edge is just *barely* touching, if at all.

One word of encouragement: it took me many, many frustrating hours spread out over many, many frustrating weeks (or months) until I finally got the hang of convexing blades. I was quite good at doing ordinary bevels with stones, files, etc., but just COULD NOT seem to get a convex edge sharp.

Finally, after much practice, it kind of just came. Some of it was with the light touch. Sometimes it helped to remove some of the stock with some other sharpening method, like a file or coarse stone, where there was just too much steel. One thing I found helpful was to use green chromium dioxide buffing compound (which you can get from Lee Valley Tools), as that seems to work very aggressively as a stropping compound. I've graduated to the point where I can put hair-popping convex edges on khukuris, etc., and I've got to say that I like their performance.