convex sharpening question

raindog101

raindog101

Joined
Jan 22, 2007
Messages
3,131
I have been following the numerous discussions on how to sharpen a convex edge, and have looked at the Bark River site for their tutorial as well. I think I'm ready to try it. So, I went out today and bought a mousepad at Goodwill for $0.49, then headed over to Home Depot to get some 1500 grit and 2500 grit sandpaper and some stropping compound. Well, Home Depot only carries sandpaper up to a 400 grit. So, where can I get sandpaper in this grit, without going online? Do lumber stores sell it? Hardware stores like Ace and True Value? Lowe's? Someone help me!
 
Just look for the wet/dry 3M sandpaper at any Wal-Mart, automotive section, or any auto parts stores, auto body section. Grits up to 1500
 
Wal-Mart! Why didn't I think of that! And auto body. Man, I was on the completely wrong track with the lumber/hardware thing. Thanks a bunch...
 
Look for some 2000 too, as your final sharpening (stropping) before the leather. I found some at The Woodworker's Store.
 
I've never looked for it at Wal-Mart, but Ace hardware has paper by the sheet up to 1500.:thumbup:
 
Any AutoBody Supply store should have it. Remember when using a wet/dry soak it in water for apx 10min. This paper was designed for sanding Clearcoat after a car has been painted. Hope this helps.
 
You aren't buying sandpaper (used for wood), but carborundum gritted wet and dry for metal. The autobody or car parts shop is the place to go. glue it to the mousepad with double sided tape or Spray Mount.
 
So, what happens if I don't soak the wet/dry paper before using it? Is that bad for the blade, the paper, or both? And does that have any affect on the adhesive (maybe double sided tape or something similar) I will use to attach it to the mousepad?
 
I don;t use any water (or oil) on my wet/dry (UNLESS I'm using it on the Sharpmaker stones to re-bevel a standard-grind edge). I use it dry on my Bark River knives, which are the only convex-grind blades I own. The reason I don;t is because most of the Barkies are A2 carbon and I just don;t want to mess with wiping them off often while stropping (sharpening). Dry works just fine when you're using 1000 grit and up.

When you're sharpening a convex edge, don;t think so much in terms of "grinding" because you're only grinding in the technical sense. Really, you're polishing. Very little pressure is needed. I've read this and now had plenty of time to practice it, and it works. Light pressure...polishing with very fine sandpaper. You don;t need water for that.

The purpose of water or oil is to help float the slurry that develops as both grit and steel are removed. Not only does the slurry add to the grinding process (if you seek slurry as you grind) but the lubricant also helps to carry the slurry away so your tool edge is exposed to sharp, clean grit more often. What I mean by "seeking the slurry" is that you consciously try to include the slurry as you sharpen. You don;t do that with Bark Rivers or other convex edges. It just doesn't work that way - it's not how "stropping" works. That works with woodworking chisels and other like tools, though.
 
OK, gotcha about the water. I had never heard of soaking the wet/dry paper before stropping, but I am just a newb to the world of convex sharpening, hence the thread. Also, when it comes to stropping, will an old leather belt work, and what is the best compound to use on something like that?
 
I would assume a smooth leather belt will work, mounted on a piece of MDF, plywood, hardwood, or something similar. You could even use plate glass, ripped to the width and cut to the length of the belt. I glue mine down with contact cement, but yellow, white, or liquid hide glue will work just as well (just takes longer to dry). My first strop was glued down with 3M spray adhesive. Don;t do that....it won;t hold for long if you put any heat to the strop.

You can try the red rouge, but I would hunt down some green and white. Maybe black too. The coarseness goes black, green, white - coarser to finer. Where does red fall? I don;t know.

Also, soaking (or at least wetting) wet/dry paper is solid advice - for any other purpose. But not for stropping a Barkie. Not in my opinion, anyway.
 
Thanks Stretch, but I think I'll skip all the extra work and just get a strop from Knivesplus, as someone else recommended on another thread. For $15, how can you go wrong? And, I'll pick up the Cold Steel Bushman at the same time, a knife I've been wanting to try out for a while, and again, for $15, how can you go wrong?
 
Yeah...that'll work. What's with the Avitar? What is that a picture of? I've been looking at it trying to figure out what that is.
 
Hope you don't mind me tacking on a related question.

Some people prefer a mouse pad and some people prefer leather as the base for the fine grit paper. What is the difference and why do you like one instead of the other?

Thanks
Sean
 
SeanH some like me even prefer a bench hone to convex sharpen. The difference is the hardness of each. a mouse pad is real soft and you need a very light touch with it. Leather is a little harder still requires a light touch. A hone or stone is hard and you need to very the angle to get a convex shape. You can press hard or soft with a stone. People also use wood, sandpaper and cardboard to sharpen convex edges.
 
Well I started with a mousepad because BRKT recommended it in their tutorial. I still use it with a strip of 1000 taped on one side and 1500 on the other. But, I need a place for the 2000. SO I mounted some 8-9 oz leather on a maple board about 3" x 11" x 3/8". and the 2000 stays there. I like it better than when I was using in on the mousepad, probably because, like db says, it's a little more firm.

Only one problem - leather has some inconsistencies...it's not as smooth and flat overall as a mousepad. But they haven;t cause a problem yet.
 
You must log in or register to reply here.
Back
Top