Large Knife Grind Question

blgoode

blgoode

Knifemaker / Craftsman / Service Provider
Joined
Oct 3, 2003
Messages
7,145
Well...after some learning I am going back to my first knife. It is a 13" overall knife and I currently have a convex edge on it. Its not as thin as I'd like but like I say its a large blade. Good for chopping around the camp.

Here is my question. Would it be best to work the convex edge thinner or regrind to a flat grind? The thiskness before the convex edge is a hair larger than .025" with a steep bevel so it overall is thicker than it measures just before the convex grind.

Thanks for the help.....

http://www.bladeforums.com/forums/showthread.php?s=&threadid=284084&highlight=blgoode

here is the link to my first knife post
 
I always do a flat grind about 2/3rds of the way then slack belt the convex. Works faster and you get one heck of an edge!
 
.025"

you mean 0.25"?

Otherwise, you're blade is plenty thin at .025"...:eek:

If you mean 1/4" thick, then you still have plenty of space to grind. If it were me, I'd start grinding a nearly-full flat grind, so that it's flat from the spine to about 3/8" away from the edge, and then finish it off with convex from there. You might end up screwing up you lil' ricasso doodad, though. Just keep that in mind.
 
Like the others, I've found that a FULL convex is not a great edge. A flat grind with a convex edge is what I try for.

The exception is a new sword pattern I'm working on. It has a full, double edge convex for the first 1/3 of the blade and fades to a reflexed, full flat grind single edge with a fuller for the rest of the blade.
 
I'm gonna differ from Dan on this one (I think this is the first time). I believe a good steel can hold an edge just fine at .015".

I just re-sharped a 2.5" wide kitchen blade for a customer. It is a full flat grind to under .015" With a bevel that acute it's very thin for the first 1/2 inch. After sharpening I proceeded to do the ax test on some old fir. Not a chip or roll over in sight. Then did the business card split with it (see other post).

It was S30V, but still.

Now Dan knows how to seriously sharpen a knife, so I won't argue with the man (besides he's bigger than me too!!). But personally I like thin for many applications.

Steve
 
Originally posted by blgoode
The thiskness before the convex edge is a hair larger than .025" with a steep bevel so it overall is thicker than it measures just before the convex grind.
Click to expand...
If he's talking about the width of the final bevel, I'm with you, Steve.

If he's saying it's just a hair over 0.025" up to the spine (and if that's what you're saying too) then you guys got some voodoo you need to teach me. 1/32" is only .031", so you're telling me the blade is less than 1/32" thick? .015 would be more like 1/64" thick. That's thinner than any fillet knife I've ever used. That'd make a pretty poor camp knife, and I certainly wouldn't be messing around with regrinding something that thin.

Just my 0.02

Dan
 
Dan,

OK We're on the same page. Can't imagine a blade .025" at the spine that you can actually use for something! Maybe a razor?

Steve
 
no no...Its a .025 at the edge but the taper to the spine is a heavy one. This blade was meant as a camp chopper so I know I wont slice great with it. The bevel is about .75" from edge to a full 3/16" thick. not bad but....it was my first blade. It does slice through paper though. I had my Khukri as a go by when I made this one so its a beefy thang!!
 
well...I just chopped 1/2 way through a 2 x 4 and it still slices carboard and paper both so mayby its okay...I'll just chalk it up to experience??
 
Well...I just got the calipers out here at work. What I have is a bevel that is 3/4" total. The steel is about .027 closer to the handle and goes to .037 twards the tip. I did make this to be a chopper so I guess I need to continue searching for the ultamite blade huh?

Now I wish that riccaso wasn't shaped like it is. I could just grind on it easier......but the way its shaped it would be tricky....
 
Well....hell! I may just have to get it to a usable grind and to hell with the ricasso look.........It will be a double grind sort of?? I better think this one through....
 
Dude, just leave it alone. Make another one. Let this first sit in a drawer for a year or so. You'll dig it out sometime in 2005 and say - "Holy crap! I guess I have gotten better!"

Whatever you do, don't sell it anybody - don't give it away, either. You need it as proof!
 
sounds like a better idea than a regrind!!
 
Well...I went and bought calipers...and now my measurements are true... I basically turned this into a good camp knife. My next one will be better but this is a keeper now.... She is .030 closest to the grip and about .035 at the sweet spot. Not hair popping but shaves your leg pretty clean. Slices now!!! I left spme of the fine grind marks and after a lime..and an apple looks to be a nice used blade. I like it. I'll scan it Monday. I had to grind off alot of thickness but it was a good thang!!!

Thanks guys.....
 
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