What Compounds are Best for Convexing?

[bcknives]

I would like to start to convex one of my utilitarian knives. The way I want to do this is by stropping, like how Virtuovice does on youtube. Right now I have been using Mother's Mags to just put a mirror polish on it, but my question is, is can I start convexing with Mother's Mags?
I appreciate all the help I can get... I'm still new to this!

Thank you!

 

[Obsessed with Edges]

Unless you use some EXTREMELY coarse & aggressive compound, convexing on a strop alone will take a very long time, and probably will result in an over-polished edge with less 'bite' than you'd like. Generally, the longer it takes to get it done, the more likely the edge will get rounded off. Mother's Mag polish is meant for polishing, which means it's nowhere near coarse or aggressive enough to remove metal quickly, as would be needed for convexing.

For most steels, silicon carbide wet/dry sandpaper is the best way to get started, by far, UNLESS you use a belt grinder. And if the blades aren't extremely large & thick, sometimes it can be done very quickly with one grit. Anything in the 400 - 800 range can quickly convex the edge bevels on most pocketknife or folder-sized blades, and will leave a nice satin finish with some real 'teeth' in the edge. It's especially effective when used directly on hard backing, like glass or hardwood, but can also be done using a firm & forgiving backing like thin leather or stacked paper, over hardwood or glass. If you wish to take the convex to a very high polish (mirror), then following the starting grit with progressively finer grits (600/800/1000/1200/1500/2000+) will do that well.

Once the convex bevel is set with the sandpaper, THEN go to the strops. I've had a lot of good results using diamond compound (1 micron) or silicon carbide 'stick' compound (black; 1 - 3 micron) on the rough side of leather.

 

[stitchawl]

The folks over in the Bushcraft forum tend to love their convexed edges. They advocate using sandpaper on an old mousepad and a very light touch. Not being a convex-lover myself, I haven't tried this, but they all swear by it. The neoprene of the mousepad gives just enough curve to form the edges they prefer. Keep in mind though that they are generally using fixed-blade knives with heavier blades.


Stitchawl

 

[Obsessed with Edges]

The folks over in the Bushcraft forum tend to love their convexed edges. They advocate using sandpaper on an old mousepad and a very light touch. Not being a convex-lover myself, I haven't tried this, but they all swear by it. The neoprene of the mousepad gives just enough curve to form the edges they prefer. Keep in mind though that they are generally using fixed-blade knives with heavier blades.


Stitchawl

The downside, to me, of using the mousepad is, it's just too soft. 'Very light touch' is mandatory to keep from sinking too deep into the backing and over-rounding the edge or the shoulders, which then means the going will be much, much slower. Sandpaper is much less aggressive that way, when pressure is very light and the substrate is soft. Feels like sharpening on a pillow. I like using firmer surfaces, which are much more tolerant of using heavier pressure during the initial grinding stages, and even to some degree in finishing stages. Much less likely to round off the cutting edge on a firmer surface. My convex edges didn't start getting really sharp until I started transitioning to firmer backing for the sandpaper, eventually to using hardwood backing, which produced my sharpest convex edges yet.

Edit:
Sort of a double-whammy when using sandpaper on very soft backing. The softness of a mousepad will greatly exaggerate how much the paper 'rolls' or forms itself around the edge, under pressure. This makes it all the harder to minimize the rounding/blunting of the edge.

 

[brady.kevin07]

The downside, to me, of using the mousepad is, it's just too soft. 'Very light touch' is mandatory to keep from sinking too deep into the backing and over-rounding the edge or the shoulders, which then means the going will be much, much slower. Sandpaper is much less aggressive that way, when pressure is very light and the substrate is soft. Feels like sharpening on a pillow. I like using firmer surfaces, which are much more tolerant of using heavier pressure during the initial grinding stages, and even to some degree in finishing stages. Much less likely to round off the cutting edge on a firmer surface. My convex edges didn't start getting really sharp until I started transitioning to firmer backing for the sandpaper, eventually to using hardwood backing, which produced my sharpest convex edges yet.

Edit:
Sort of a double-whammy when using sandpaper on very soft backing. The softness of a mousepad will greatly exaggerate how much the paper 'rolls' or forms itself around the edge, under pressure. This makes it all the harder to minimize the rounding/blunting of the edge.

What I have found to work for me is sandpaper on top of something hard like a 2x4 with a few stacked paper towels between the wood and sandpaper.

 

[mrdeus]

I've had more success with sand paper on a strop than on a soft mouse pad. I've only convexed 4 knives though.

 

[NvG79]

Plz check knivesshipfree for an entire tutorial on convexing your edges! Great short films that'll help you get up to speed!!