OT: Convex edge sharpening

Sylvrfalcn

Sylvrfalcn

Joined
Jun 4, 2002
Messages
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Slow day, lot of hurry up and wait, during the course of which I ran across this. What this is, is a live demonstration of how to sharpen a Laguiole folder that I got from Laguiole's website (I don't generally care for folding knives, but I do have a Laguiole, excellent craftsmanship and very traditional styling). If I'm successful in posting the URL, what you're going to see is a very simple and unsophisticated approach to sharpening a knife. Yvsa will love this one because it proves his point about convex edge sharpening being a natural deal having nothing to do with rocket science. Especially note how the guy rocks the blade during stropping.

Anyway, here goes, let's see if this works.:D

videosharpening.jpg


Right, let's try this then,
http://www.laguiole.com/index2.htm
 
Bruise it aint black magic, its a voodoo curse. That kid you looked at cockeyed in Kindergarten never forgot, and because of that has placed a voodoo curse on you so that you will never be able to sharpen a razor sharp blade muwahahahaha :D
 
Let me tell y'all why this little video clip tickled me so much. I grew up understanding that all you needed to sharpen a knife was a good whetstone. Over the years I've seen throngs of guys buying special jigs and "sharpening systems" and I couldn't figure out why. After all, in my simple country mind you just put the blade on the whetstone and you sharpen it, duh.... Did'ya see any jigs, guides, or other gadgets in the demo video? Nope. Did he successfully sharpen his knife? Yup. As Yvsa says, "it's not rocket science". It's a physical skill obtained through experimentation, practice, and repeating what works. In other words, it's kind of like tying your shoelaces.:D

Sarge
 
In other words, it's kind of like tying your shoelaces. >>

I knew there was a catch.


munk
 
I have to admit, that I used to be in the overly complicated camp. The more complicated my setup got, the worse the results were, and the longer it took. Its amazing how the results improved as soon as I started clearing the junk out.
 
Originally posted by Sylvrfalcn
Yvsa will love this one because it proves his point about convex edge sharpening being a natural deal having nothing to do with rocket science. Especially note how the guy rocks the blade during stropping.
Click to expand...

Thanks for the link Sarge! That's the point I've been trying to get across in pictures.:D It does prove my point quite well!
The only thing I noticed is that is one dayumed Hard strop, but one helluva neat idea of having it glued to the top of the whetstone box cover. I like it, a lot!!!!:D
I use neatsfoot oil on my strops to initially load them as it makes the compound adhere more easily, but this has made me think about using water to do the same job and then perhaps blow-drying it with a hot hair dryer to harden it.
I can see the advantages of having a hard strop.
It's similar to using a hard buffing wheel for the final edge after polishing.
However my soft strops makes it easier to keep the convex edge as the leather gives just enough.
A couple of swipes on the hard strop would really polish the edge though methinks.:)

I sometimes use the same method the Laguiole video shows as to the moving the knife back and forth on the whetstone if I have a lot of material to remove or if there's been an accident and the blade has a nick in it.
But it doesn't matter if you use this technique or just use the hone for one way swipes.
You will get the same results.

The video shows an experinced man sharpening the knife and I'm going to assume that an initial edge has already been established.
The initial edge centers the edge and is sharp with a rough edge.
I have to stress that it's so very important for a novice to get a burr all along one side of the blade before doing as is shown in the video by flipping the knife back and forth.
That takes experience.
The only thing I realy have to critique is that almost anyone can get a knife that sharp. It's when you can shave very thin strips of the very edge of the paper without it snagging or dragging is when you've proved your mettle.
Pun intended.:D

Like everything else it just takes practice, practice, practice!:)

Edit:
Yep! Just like Sarge said, "In other words, it's kind of like tying your shoelaces.":D
 
I learned to sharpen free hand on stones also, really like the water ones. I agree it's a skill everyone should learn. That said, it sure is nice to have a slack belt sander to put a nice convex edge on a blade and hone it too.
2003234968509575516521.jpg

Regards,
Greg
 
I use an Eze-Lap diamond rod the size of a kitchen steel. After a couple years now I'm not up to Yvsa's level, but freehanding a bevel into an edge isn't a big deal anymore. One of these days I'll get a good file and stone it down to smooth. That'll do it up right. Hey, the cheap stones don't cost much and you can afford to toss them.

One day I came across these two smooth triangular files or deburrers...forget I said that. Dan Dennehy used to make 4 or 5 inch triangular bladed "ear" knives for cops or military. I don't believe they were for removal of ear wax.:D
 
Originally posted by Ripper
I learned to sharpen free hand on stones also, really like the water ones. I agree it's a skill everyone should learn. That said, it sure is nice to have a slack belt sander to put a nice convex edge on a blade and hone it too.

Regards,
Greg
Click to expand...

Greg has it down!!!!:D
One thing I didn't mention about the slack belt sanders is that you have to be very careful for several reasons.
First and foremost is to watch what you're doing very carefully so as to NOT get Hurt!!!!
A cut belt can deliver nasty cuts and leave ugly scars.:(

Second most is to be extremely careful not to over heat the blade!!!!
Use a large container, I use a Rubbermaid wastepaper container, with enough water in it to cover the blade or a smaller container with a cloth large enough to hold lots of water.
If the blade gets to hot to hold onto it's too dayumed hot. It's so very easy to ruin a blade if you don't know what you're doing!!!!

This is another place that some old knives from the flea market come in handy.
Pracice on them until you're sure of yourself.

Speaking from experience,
Yvsa.
 
Yvsa, I've occasionally taken the stone in one hand and brushed the knife edge with it, instead of running the blade along the stone where it rests. I've never heard of anyone doing this. I just did it because I get a good feel of what I'm doing from holding the stone, and I have convinced myself I can put a convex edge on easier.

I just grab the blade with one hand and the stone with the other. Bad?



munk
 
munk - seems like I've discussed this somewhere on bladeforums before...anyway, it will be a repeat for some, I guess.

The field workers in Guate would sharpen their machettes by sticking the point gently into a tree and the bracing the butt against the chest. Then they would run the file/stone/whatever up and down the edge to sharpen/align.

It was like clockwork to see these guys stand up and sharpen every 2 hours or so...literally "in the field".

Dan
 
Munk youre not alone, Ive sharpened 29" blades in this manner. Never could get used to bench stones. All the ones I got are small enough to fit in the palm of my hand. Anyways, I prefer holding the stones, feel like I can get more accuracy. Then again I was too cheap to buy more expensive bench stones, and their subsequently required mounts. Didnt help the one time I did spring for the extra $$$ it was for those gosh forsaken Japanese water stones. While they worked, all the prep work just was too much for me. I just got way to used to sharpening saws into razors in under 10 min (with the water stones it took 15 just to prep).
 
Originally posted by munk
I just grab the blade with one hand and the stone with the other. Bad?

munk
Click to expand...

Munk, nothing's bad if it works. :D

I've seen a hundred different ways to sharpen knives from all the places I've been.
One of the most common and widespread I've seen is an old man spitting on his whetstone and running the edge in circles on it, first one side and then the other.
I can guarantee you will always find those knives razor sharp!!!!:D
 
I only dream of getting convex edges as sharp as you guys. :o

I just recently figured out the secrets to razor single and double bevels (JKM and folders).

Now I got one more thing on my list! `;)
 
"While they worked, all the prep work just was too much for me. I just got way to used to sharpening saws into razors in under 10 min (with the water stones it took 15 just to prep)

Fed, you mean the soaking them in water? I just keep mine in a big flat tupperware-like container, soaking all the time. But they are soft, so if one is sharpening a lot, they are a pain to keep flat because they wear fast. But wearing fast means new abrasive particles constantly appear, so they cut fast.

I just let mine dish out and use them for convex edges.:) The khuk recurve rounds the corners a bit too. Actually the finer ones aren't dished/rounded because the final polishing steps take me much less strokes than getting the edge in shape with the coarser stones. Sometime, I'll fork out for more coarse ones and reserve those for flat grinds. Meanwhile, I use some other coarse/med stones for flat grinds and edges.

For me, the waterstones just seem to suck the blade onto them and I get better tactile feedback that I'm at the right angle(s). Maybe it's the mud that builds up. They seem leave a finer finish than other stones I've used with similar cutting power too. I think that's because the mud gets finer as one works. I just put the stones on a damp dish-towell on the kitchen counter and they seem to stay put OK.

I gotta try those Norton stones Yvsa likes.
 
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