any reasons not to sharpen knives using sandpaper?

[cziv]

I don't see a picture richard thurman, is it in another thread? OOPS - found it post #33. Looks pretty benign, but great fro touch-ups I'd bet.

 

[kamagong]

You can put a heck of an edge on a knife using sandpaper. I convexed the edge of my Military using sandpaper and leather.

 

[sircantaloupe]

Dang man, that is a beautiful edge!

When I convex a knife, I don't bother trying to avoid scratching the rest of the blade. I'm too clumsy, so it's inevitable. But that is a great look.

 

[BryFry]

I'll have to take some more pics of some of the edges I've done with sandpaper, but here's one of a big Kuhkri that I reprofiled and convexed with paper...

I've done some since that look even better, but I have to say that for me, I get the best overall results with sandpaper. I know that one can get a nice pollished edge using only stones, but you need a pretty nice and expensive set to get the same pollished effect I think.

 

[ChapmanPreferred]

To better answer your question in the original post, I think serrated edges would be the only draw back I can imagine.

 

[BryFry]

To better answer your question in the original post, I think serrated edges would be the only draw back I can imagine.

I haven't tried it, but I bet you could wrap your sandpaper around a small dowel or stiff wire and use it on most serrations.

I've used a similar method for recurve blades where I wrapped the paper around a pringles can or large dowel, and it worked great!

 

[moonwilson]

I use sandpaper to sharpen knives all the time. It works great for me, I've had much better results with high-grit sandpaper and stropping than I have had with any stones or gadgets. It's all about learning what to do, and doing it properly. There are many different ways to make a blade sharp, using sandpaper is one of them.

 

[richard thurman]

I don't see a picture richard thurman, is it in another thread? OOPS - found it post #33. Looks pretty benign, but great fro touch-ups I'd bet.

I have had my knife where it out not cut butter and then I use the sharpner and once again it is shaving my hair.

 

[singularity35]

You an put a heck of an edge on a knife using sandpaper. I convexed the edge of my Military using sandpaper and leather.

excellent!:thumbup:

 

[cziv]

I've been working on a stripped & convexed Izula all day off & on and I can't get the stupid thing (I'm the dolt not the knife) to slice more than an inch of paper w/o hanging up and that was with the Sharpmaker.

I've gone from 200 through 800 grit then stropped. Then I but it on the Sharpmaker and did a 30* followed by a 40* micro bevel & stropped. No dice.

Tried two different cutlery steel rods, free handed on a course/medium stone then to ceramic then stropped. No dice. Finally went to a pull through sharpener, re-sandpapered and stropped. No dice.

So, a few minutes ago I go to cut a slice of copy paper and it slides across the top and bends it over. I threw it in the box next to me in disgust - I'm thoroughly vexed right now!!

 

[chococrazy]

I don't have a knife sharpener, but I do have various increasing grits of sandpaper. Are there any drawbacks to using them for blade sharpening? I fully intend to practice with my kitchen knives before going to my carry knives. I was thinking of getting one of those old rubber/foam mousepads and putting the sandpaper on those.

Recurves might be a problem.

Drawbacks:Not to many other than they wear out.
You shouldn't NEED to practice I didn't I got hairwhittling on my second try.
The question that arises is to convex or not to convex?
Convex Pros- Easy to maintain IF YOU HAVE THE CORRECT TOOLS you won't find a good strop in the wild (well your pants and anything soft xD) stronger, easier to get a sharp edge IMO.
V edge pros- Easier to find things to sharpen with, more people know about this.

If you want a convex sharpen with a mousepad going to a girt of about 2k.
If you want a V edge take the sandpaper, and using a spray adhesive glue it to a piece of glass, sharpen as if it was a bench stone, but use a stropping motion.

 

[BryFry]

I've been working on a stripped & convexed Izula all day off & on and I can't get the stupid thing (I'm the dolt not the knife) to slice more than an inch of paper w/o hanging up and that was with the Sharpmaker.

I've gone from 200 through 800 grit then stropped. Then I but it on the Sharpmaker and did a 30* followed by a 40* micro bevel & stropped. No dice.

Tried two different cutlery steel rods, free handed on a course/medium stone then to ceramic then stropped. No dice. Finally went to a pull through sharpener, re-sandpapered and stropped. No dice.

So, a few minutes ago I go to cut a slice of copy paper and it slides across the top and bends it over. I threw it in the box next to me in disgust - I'm thoroughly vexed right now!!

My first guess would be that the two angles of your edge may not be coming fully together. Try holding the knife under a good light and if you see light glinting off the very outer most edge then you are not quite there.

Pluss 800 grit is not all that fine. Most people go to 2000, THEN strop. Also when using sandpaper keep in mind that you do not want to use much pressure. Use a light touch, this means you usually want to stay with your courser grits until the edges just come together. You can tell when this happens when you see a tiny little wire edge appear. -This is caused when the two edges meet, and a tiny bit of steel gets folded over or rolled.

Once this happens stop, go to your next grit and BE GENTAL! give it a few passes then on to the next finer grit, and so on until you finish on your strop. -If you want a super tiny micro-bevel just tip the blade up slightly higher on your final stroping, but still keep the pressure light.

...Hope this makes sense...

 

[chococrazy]

I've been working on a stripped & convexed Izula all day off & on and I can't get the stupid thing (I'm the dolt not the knife) to slice more than an inch of paper w/o hanging up and that was with the Sharpmaker.

I've gone from 200 through 800 grit then stropped. Then I but it on the Sharpmaker and did a 30* followed by a 40* micro bevel & stropped. No dice.

Tried two different cutlery steel rods, free handed on a course/medium stone then to ceramic then stropped. No dice. Finally went to a pull through sharpener, re-sandpapered and stropped. No dice.

So, a few minutes ago I go to cut a slice of copy paper and it slides across the top and bends it over. I threw it in the box next to me in disgust - I'm thoroughly vexed right now!!

You are going from a convex to a stone? That's pointless as a convex edge has no degree, as it's circular. Going to a stron will either dull the edge or remove the radius from the circle give you you a dull, and weird look edge.
A microbevel will just dull the edge also.



On the pull through part you made me cringe :O It better have atleast been a ceramic pull through, and not a carbide.

You also need higher grit sandpaper like 2k plus. I'll edit this post in a minute with a link to my first convex thread (if I can find it)!



If all else fails and you want to give up your Izula I'll accept it with open hands
I need my first fixed blade XD.

Edit: here it is http://www.bladeforums.com/forums/showthread.php?t=724811 go to post #10 for my tips.

 

[cziv]

BE GENTAL! give it a few passes then on to the next finer grit, and so on until you finish on your strop. -If you want a super tiny micro-bevel just tip the blade up slightly higher on your final stroping, but still keep the pressure light.

Okay BryFry, I've been doing it with a LOT of pressure. Also, I do circular rotations. Should I be using the sandpaper like a strop?

chococrazy, I know buddy but I get po'ed and end up putting a working edge on it with my sharpmaker or a flat stone that I have.

Later, I try again with renewed enthusiasm!

 

[chococrazy]

Okay BryFry, I've been doing it with a LOT of pressure. Also, I do circular rotations. Should I be using the sandpaper like a strop?

chococrazy, I know buddy but I get po'ed and end up putting a working edge on it with my sharpmaker or a flat stone that I have.

Later, I try again with renewed enthusiasm!

Use a stropping motion. Circular motions MIGHT work with the LOW grits, but I would recommend stropping.
You should be sharpening at a NEARLY flat angle when converting from V to a convex. With a firm amount of pressure.
For maintaining use/ after you've got a reprofile down raise the angle a tiny bit, and sharpen with little to no pressure.

 

[stabman]

Maybe it's different in Michigan, but I can't find 2K grit sandpaper around here. If I could, I'd probably have to agree with your statement.

Check the automotive section; that's where I found mine.

 

[BryFry]

Okay BryFry, I've been doing it with a LOT of pressure. Also, I do circular rotations.

Yes! that could be a problem!

Yeah, when using sandpaper you always want to drag the blade edge trailing, never lead with the edge or go circular like you do on a stone.

One of the possible problems with using too much pressure with sandpaper is that you can round off the edge, especially if you are laying the paper on top of something soft like a mouse-pad or leather. -Definately not good for a razor edge!

-But it will work great if you take it easy. -just takes practice, and a little trial and error.

 

[zyhano]

This will give you a very good learning tool for sharpening basics, and then down the road, you may want to experement with other styles of sharpening

+1 this has been my experience too.

 

[vice o33]

Great thread Now I'm keen to have a try i've allway had trouble getting a knife realy sharp,:thumbup:

 

[sircantaloupe]

A simple rule of convex sharpening - the higher the grit, the lighter the pressure you put on the blade. When you hit 1000 to 1500 the weight of the blade is enough.