Convex with strop and sandpaper - is there a burr??

[db]

Don't discount how fast and easy sandpaper can be to reprofile a blade to thin and convex it. Like Rob has said you don't need to limit to trailing strokes. Back and forth to reprofile is the way to go on some coarse sandpaper made for metel. Wood sandpaper will work as well just not last as long. I think you'll be surprised how fast it is once you try it. Diamonds are great and I used a clamp system for years. However, now that I've gotten the convex bug I convex everything and have for the last number of years. Not even real sure where my clamp systems are.

 

[boki_zca]

I always use just leather backing under sandpaper and it produces great results!Its easy to do slight convex edge on a stone too, much faster than with the sandpaper.I like slight convex edges, something like Murray Carter sharpens on his knives, and you get pretty strong edge and really sharp!

 

[neeman]

I spent about 10 minutes regrinding the edge on the clip blade of my old Boker stockman from Extra Coarse to Fine to Extra Fine DMT diamond stones using the aligner jig and the zip tie spacer. Then I finished it off on the strop to remove the burr and get some more polish.

I could feel the burr forming almost immediately, it was almost too easy with the soft 1085 steel on it. The edge I got shaved hair with ease and I'm betting if I could spend some more time I could get it to whittle hair. My next step is to thin out the bevel with some sandpaper on the strop.

db, I know what you mean about the angle, I think for now I will stick to using the jig to form an initial edge since it was so easy and fast compared to the time spent going through the grits with the sand paper.

Sorry to bring up on old thread but it was referenced recently

So the edge is from the DMT Aligner and then stropped
The shoulders of the grind are knocked off by using sandpaper
BUT the sharpened edge is not touched by the sandpaper

Is this a convex grind?
Or a 'regular' flat grind with rounded shoulders
How will you resharpen this knife when stroping is not enough?
Back to the Aligner?

Thanks

 

[Obsessed with Edges]

Sorry to bring up on old thread but it was referenced recently

So the edge is from the DMT Aligner and then stropped
The shoulders of the grind are knocked off by using sandpaper
BUT the sharpened edge is not touched by the sandpaper

Is this a convex grind?
Or a 'regular' flat grind with rounded shoulders
How will you resharpen this knife when stroping is not enough?
Back to the Aligner?

Thanks

It's not that the sharpened edge isn't touched by the sandpaper. It's inevitable that it will be, at least somewhat, when sharpening freehand. The idea is to minimize how much the contact with the sandpaper rounds the actual apex, while utilizing the sandpaper to gently smooth & convex everything behind the apex. Some believe a convex isn't a 'true' convex, unless it extends all the way to the cutting edge. Problem is, it's virtually impossible to do that without somewhat rounding off the apex or widening the edge angle, or both. Any cutting edge that's truly 'sharp' is always going to look essentially like a 'V' when viewed at magnification. If the cutting edge (apex) was actually convex (rounded), it wouldn't cut worth a darn.

As for re-sharpening when it gets a bit too dull for the regular strop, just 'strop' with higher grit, using the sandpaper. This is what makes it my favorite sharpening and maintenance method. The stroke is always the same, and the grit is the only thing that changes, depending on the needs of the edge. Obviously, when the apex is dull, the sandpaper will actually have to make contact with it to sharpen it. If one can strop successfully to sharpen, without rounding or degrading the edge, one can also do the same with the sandpaper. The stroke is exactly the same, and the same fundamentals apply (light pressure, maintaining the angle). Getting comfortable using sandpaper this way will come with more practice. Both stropping and sandpaper sharpening will produce better results, the firmer the backing underneath the stropping/honing surface is. Much less chance of rounding off edges, the firmer the backing becomes. The convex of the steel behind the apex will still be there (it's freehand), but the severity of the convex will lessen on a firmer backing. That's almost always a good thing, unless you're sharpening a splitting wedge.


David

 

[neeman]

If the cutting edge (apex) was actually convex (rounded), it wouldn't cut worth a darn

. Both stropping and sandpaper sharpening will produce better results, the firmer the backing underneath the stropping/honing surface is. Much less chance of rounding off edges, the firmer the backing becomes.


So mouse pads are much too soft
A firm surface would be a leather strop on wood backing ,like over a stropping bat from Bark River?

 

[Obsessed with Edges]

So mouse pads are much too soft
A firm surface would be a leather strop on wood backing ,like over a stropping bat from Bark River?

In that comparison, I'd definitely take the leather-over-wood, as opposed to a mousepad. I've never liked using mouse pads for this, especially for refining the edge. It's much too soft for my preference. And the closer one gets to the apex, while convexing, a still-firmer honing surface is even better for producing crisp-as-possible edges (this is why I like using sandpaper directly on wood, or better yet, on glass). A soft-backed honing surface is great for convexing (shaping) the steel behind the apex, but usually lousy for finishing the apex itself.


David

 

[neeman]

..........
And the closer one gets to the apex, while convexing, a still-firmer honing surface is even better for producing crisp-as-possible edges (this is why I like using sandpaper directly on wood, or better yet, on glass). A soft-backed honing surface is great for convexing (shaping) the steel behind the apex, but usually lousy for finishing the apex itself.


David

David,

Got it now conceptually, which means I have the knowladge to start convexing

Thanks

Neeman