Recurve blades?

db

Joined
Oct 3, 1998
Messages
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Hi what do you think? Will the sweet spot on a recurve blade dull faster than a bladewith a regular belly?
Since your cutting is directed more to this spot, I tend to think it would. But I really have no idea. Does any one know, or have a good idea on this?
BTW, I have found that a dull thin edge will still cut better than a sharper thick edge.
db
Tag lines suck!
 
The sweet spot will dull faster, seeing as it gets several times the use of any other part of the blade. I think it also tends to dull faster because it is almost always the first part of the blade to contact whatever is being cut, and so tends to receive more "impact dulling" or what-have-you when slashing.
 
In that case I would think a person would want to sharpen a recurve blade sooner/more often. With this in mind a recurve is more diffacult to sharpen and may not be a good choice for a everyday knife.
Any comments?
db


TAG lines suck
 
I'd usually rather try to get good performance through ways other than using a recurve, but do really admire the great performance a recurve has.

A recurve is harder to sharpen. But keep in mind a few things:

- you'll get better at sharpening them as you practice. I feel more and more comfortable as I sharpen more of 'em.

- A relatively dull recurved blade will often still easily out-slice a relatively sharpener non-recurved blade. The performance difference can be substantial.

It's a trade-off, like most things. If you want top slicing performance, a recurve is an easy way to get there. Provided, of course, you're willing to put up with a bit more sharpening hassle. I promise that as you get more practice, it gets easier. At this point, I no longer break into a cold sweat or even get the shakes when I'm about to sharpen a recurved blade
smile.gif
A year ago, I couldn't have said that!

Joe
jat@cup.hp.com
 
Thanks, Joe.

That means there's hope for us amatuers. I like some of the recurves a lot, but have hesitated to purchase as a using knife because of the sharpening issue.

Actually I do enjoy sharpening knives. There's something fulfilling about it. If a recurve takes longer and more care, that just means it will be more satisfying when you're finished - right? The question for me is how many knives will I butcher in the learning process.
 
After years of sharpening and finaly becomeing happy with my results in the last few years, thanks mainly to rec.knives and you Joe. A recurve blade might be a good challenge.
But I still have to wonder if a recurve would still be a choice for a everyday knife, for the resons given above? Yes, I can see the cutting performance would be better, but would it outlast a regular shaped blade?
db
 
db,

Actually, I don't really have a definitive answer. My gut feel is that provided you've developed enough skill on sharpening a recurved blade that you're comfortable with it, it may be a slight win.

For slicing or zipper-cutting, as I've said a sharp recurved blade will very much outperform a sharp non-recurved blade. And the recurved blade can lose quite a bit of its edge before it's down to sharp non-recurved-type performance. So if you want ultimate slicing performance in a non-serrated edge, the recurve is a nice feature -- again, provided you're willing to deal with more difficult sharpening. I don't think there's an inherent advantage or disadvantage here, just what you personally are willing to deal with.

For push-cutting the recurve has no advantage, you need a sharp edge, period. On a recurve blade, you'll be doing your push cutting on the front and bottom of the belly, which is no more difficult to get sharp than on any other knife, so there should be no disadvantage at all on the recurved blade.

Joe
jat@cup.hp.com
 
I you have the proper sharpening tools, recurve blades are a good option for a cary knife.

------------------
Jan Dirk Wijbenga

Knife philosopher
 
Since I'm the amateur here, I play the straight man on this one.

OK, J D what additional sharpening tools help on the recurve blade sharpening?

Joe may already have this covered in his Sharpening FAQs, but I'm always looking for any additional tips I can find.
 
Where are Joe's Sharpening FAQ's? I tried to find them, but the only FAQ's I could find were for Bladeforums itself.

Also, on recurve blades, the part that is actually the recurve is the part closest to the handle, right? Where the blade planform starts to suddenly dip downward again?

Sorry for being such a novice. All I've ever dealt with before is 'straight' blades.

Thanks,
Evin
 
Ok, I hope I can write this clearly. Joe's last post brings another question to my mind.
I am only talking about a slicing cut motion with a recurve. Would the end of the recurve act as a push cut? This is what I meen as you are slicing the material being cut is pushed into the end of the recurve. Therefore that part of blade should be polished/very fine edge, even if you prefer a course edge for the rest of the blade. Does this seem right?
For the everyday question I think a recurve may be more trouble than a advantage. But with all things concidered I am going to get one and find out for myself. Who knows in a year or so I may just be saying a recurve is the only way to go.

db
 
db --

I think we're pushing the bounds of what can be communicated clearly in a written medium
smile.gif
I see what you're saying, though.

I think you're talking about what I call a "zipper cut". You're drawing the knife down a relatively thin material, kind of as if you're slicing it but kind of push-cutting it along. As we've discussed, in this case the material is forced into the front part of the recurve (much like a hawkbill blade), and the cut is therefore very efficient. I haven't really explored the nuances here, except to notice that whether that part is left coarse or polished, the geometry alone makes the recurved blade a great zipper-cutter. Zipper cuts seem to often want a polished blade and sometimes a more coarse one, depending on the material being cut. I don't think it's a function of the recurve or not, but a function of the thing being cut. (geez, that was a lot of words to explain why I don't think the recurve matters for your zipper-cutting strategy!)

For true slicing, like cutting a piece of rope in half, you're still going to be drawing the entire blade across the thing-to-be-cut. The recurve blade will seem to cut with average performance until the front part of the recurve hits the rope, then the blade will bite deeply and efficiently. I mentioned this in my original review of the Krait, and noticed an article by Anthony Lombardo a few months later in Tactical Knives which mentioned the same thing. For this kind of "true slicing", you still want it to be coarse.

db, do go buy an Axis! I'd feel better if someone else was duplicating my tests and confirming (or not) the results.


Joe
jat@cup.hp.com
 
Evin -- I think the FAQs are under "knowledge base" on the front page of bladeforums, not under the Bladeforums FAQs. Spark just did a lot of work on them, so I know they're there. I actually need to look them over myself to see what new wonderful formatting Spark has done to 'em!

Joe
jat@cup.hp.com
 
Bob,

By proper sharpening tools I mean any tool that will fit the curve.
I have nothing to add to Jou's FAQ's (I think they are great) exept to say that it takes study and practice to make it work well.

------------------
Jan Dirk Wijbenga

Knife philosopher
 
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