Another question for Dan Koster on convex edges

M

mross

Joined
Nov 10, 2003
Messages
361
Dan,
I have gone through your cd. And d@m^%!, no, my knives
cannot do that! My wife now hates you because I have to get
my knives as sharp as the ones in the video! I just have to! I think
y'all can understand that. I have read the swiss army knife convex
edge faq and watched the video. So I know enough to be dangerous.

Questions;

1)How do you know if you are getting a good edge without cutting your fingernail? (That looks a little to dangerous for a klutz like me.)
When I use stones and the Razor's Edge method of sharping (of which I am very good at and can shave with the result)
I produce a detectable burr on one side of the knife. Is there anything similiar to this when doing the convex?

2) I am using the mouse pad method. I am willing to change if the block of wood and foam pad method from the video is better. How long does it take to set a good convex edge? If you use the belt sander I can see this happening very fast. This is not an option for me as finances are bit well, tight.

3) What do you look for to know if you are producing the desired result? What set the edge to be able to pass the paper cut test, fine grade sandpaper, strop with polishing compound or just strip with smooth leather?

Inquiring minds have to KNOW, ppplllleeeeaaaassseee. Really. It will save my marriage, and maybe even my life! I now have the dreaded disease known as 'convex edge envy'.
My wife says I'm obsessed, and of course she is always right! :D

I know you said you are coming out with a new cd soon could you make it
"Convex edges for Dummies" ? :)
 
Why don't you send Yvsa an email? Or ask him here. As Dan is away, and Yvsa was putting convex edges on tools before most of us were drinking milk.


munk
 
LOL.....yeah...I'm back...mostly....part of me, at least....:D


How do you know if you are getting a good edge without cutting your fingernail?
Click to expand...
Try cutting a piece of paper. Hold it in your left hand and cut about an inch in front of where you are holding it....and at a 45 degree angle. Make sense?

You could also try to shave hair on your arm, hand, etc.


To clarify:

The fingernail "glide" test is to determine how polished the edge is.

The fingernail "scrape" test is for sharpness.

I produce a detectable burr on one side of the knife. Is there anything similiar to this when doing the convex?
Click to expand...
You want to knock the burr off when doing a convex edge. Do this by moving the burr back and forth with increasingly lighter strokes on opposing sides until you get a wire edge (reflects light). Then run the edge across a piece of hard wood (slicing action). This will knock the burr off and you'll be ready to strop.

A burr produces a chisel type cut...that is, one-sided....one side "feels" (and is) sharper than the other. A convex edge is generally a polished edge with no burr.


I am using the mouse pad method...How long does it take to set a good convex edge?
Click to expand...
This will take a long time. Plan on making a small bevel at first. Won't take as long. Put in a good movie and do it for about a half-hour. Don't be afraid to hold the knife at a higher angle compared to your EdgePro sharpening.


What do you look for to know if you are producing the desired result? What set the edge to be able to pass the paper cut test, fine grade sandpaper, strop with polishing compound or just strip with smooth leather?
Click to expand...
This is a good question. At the hammer-in this weekend, we had access to a grinder, but only with a coarse belt and a 220 grit belt. Obviously, that limits the kind of sharpening you can do. I sharpened a knife I made on the 220 belt, and then used the back of the belt to "power strop" it (no abrasives added...but equivalent to a 600-800 grit belt). After that I stropped it on a "Warren Strop" - thin strip of leather with green rouge on a 1" wide stick. I could get it to shave, but it never achieved "scary sharp" status. I think what I ended up with was finely polished 220 grit scratches......make sense?

So, the short answer is that you test for sharpness after each step....as you go along. You can get good working sharpness from just about any grit....just requires a gentle final touch, and a little polishing.

The more time you spend "prepping" the edge for final stropping....(working your way up the grits) the finer the polishing will be and the better it will be at cutting paper, shaving, etc.


I know you said you are coming out with a new cd soon could you make it "Convex edges for Dummies" ? :)
Click to expand...
How 'bout "Convex Edges For (and By) Dummies".....:rolleyes:

There's still so much to learn. Thought I had almost figured it out.....but then this weekend gave me new challenges and more understanding.
 
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