Convex edges

Joined
Aug 27, 2008
Messages
151
IF you have a regular 40 degree inclusive edge can you get a mouse pad and around 400 grit sandpaper and then 1000 and finish with 2000 or 3000 grit sandpaper would you be able to get a convex edge
 
I do that all the time, but I don't see the need to go so high on the grit. I get really scary sharp convex edges with 400, 600, 1500, and strop on green compound loaded leather. Have fun, though!
 
Which is better for cutting slicing and chopping a convex or regular. and which is easier to touch up with the right equipment. If you dont have strop compound can you just use a regular leather belt? how long does it take to re profile to a convex. and if you dont like it can you sharpen it back to a regular edge
 
When convexing the edge, pretty much all that you are doing is knocking off the shoulders of the edge grind, and maybe thinning out the edge grind a bit. You can start convexing the primary grind of the blade, but you will only be able to do so much. Most blades are too thin to properly convex.

"Going back" is kind of complicated. You can definitely start sharpening your knife again, the way you used to. No problem there. Many of us do it. With repeated sharpening, the shoulders will eventually return.

As far as which sharpening method is easier, that's a personal thing. Some people find a Sharpmaker to be as easy as it gets. I think that convex sharpening (mouse pad and wet/dry paper) is brain dead simple, but I've been doing it for many years.

I usually start with either a diamond hone or 200 grit wet/dry paper to knock off the shoulders, and then use progressively higher grits to smooth and shape. Depending on the steel, the quality of the paper, the strength of your elbow grease, and how far up the blade you want to convex, it can take hours to accomplish.

Picture118.jpg

Picture106.jpg
 
You can also use regular stones.
All you have to do is grind at varying angles, from almost flat with the primary grind, to your desired edge angle at the steepest.

IMG_6566.jpg
 
I do that all the time, but I don't see the need to go so high on the grit. I get really scary sharp convex edges with 400, 600, 1500, and strop on green compound loaded leather. Have fun, though!

Yes, I agree. I max out at 2000, 3000 wouldn't hurt but it's not really necessary, but neither is 2000. You sound like you are definately on the right track Sunnyboy.:thumbup:

BTW, those that posted pictures... SWEET EDGES! GEEBUS!
 
Nice work on the Millie, I reprofiled the edge on my D2 Para, which turned it into lightsaber. I plan to convex my Chinook one day soon... however my sandpaper methods obviously need improving as I've never got good results with edge trailing strokes.
 
When you're using the mousepad and sandpaper method do you just lay the blade flat on the sandpaper/mousepad combo or do you angle it slightly like you would when using a regular benchstone?
 
you angle it. I have gone as low as 40 grit when starting out. When I convexed my Busse FBMLE It took multiple sessions lasting hours each. If I had a good course diamond stone, I could have cut that time dramatically. A big heavy 10 inch blade takes some time for sure.

I have convexed smaller knives in much less time.

I find them really really easy to maintain. I just give a few strokes on my strop at the end of the night if I have used it.

The highest grit I have ever used with sand paper is 600, then to y 4 sides strop bat. I have actually gone to my strop after a quick pass on my belt sander at 200 grit, and it was stupid sharp.

IMG_1837.jpg

IMG_1735.jpg



this edge was from a 150 or 200 grit belt sander directly to the strop for a few quick passes to test it. It is definitely stupid sharp now. I can shave my beard hair with it. A small bumble with it cut my right thumb to the bone and severed the nerve. I have never had a cut with such little force or pressure cut so deep.
IMG_1720.jpg

IMG_1811.jpg

IMG_1814.jpg

IMG_1815.jpg


(sorry about that, just threw those in to see if you were paying attention, but that is proof that the convex edge on that sucker was sharp)

before and after shot, nothing but some tlc on a strop. This one had a toothy edge grind. Got the edge mostly convexed with a some relaxing stropping in the evenings.
IMG_1210.jpg

After a some stropping
IMG_1291.jpg


Home made strop bat, a piece of square wood, and a broken belt that I stepped on and broke the buckle.
IMG_1381.jpg

IMG_0990.jpg
 
Last edited:
Back
Top