I have done much the same thing with fine grades of wet/dry sandpaper like what the auto body guys use down at the paint shop!!
Some like to glue the sandpaper to a piece of glass so as to have a nice flat work surface, but I usually just use the back of one of my diamond stones as a flat surface to work on!!
Kind of amazing what a 1200 grit or so piece of W/D sandpaper will do to the edge of a good blade!!!
Hi Sheepdog! Good to see you here;)
Fine grade sandpaper sharpens nicely.
I have some around, keep a small piece of it in my Altoids kit, you can slip some in your wallet.
I used to use a nice flat surface too, generally wood. Glue some sandpaper in a small wood tablet, that was the bladesmith trick I read somewhere, think it was Abel Domenech's website ( knife author, great guy, met him a couple times).
Said a little tabled with sandpaper in one side and a piece of leather in the other side (with buffing paste) was the best sharpening/stropping tool anyone ever gave him.
After experimenting with the hard surface+sandpaper combination, I tried the foam+very fine sandpaper combination.
At least for me, the soft pad provided by the foam works much better.
I know knife makers and knife specialist around the world are suffering a small convulsion as I write this words, but that’s been my experience.:)
I tried them both and the softer foam gave me much better results every time.
The hard surface is much less forgiving, the angle has to be just perfect every time, which of course always happens when using sharpening stones, reason why its so hard to learn how to sharpen a knife well.
When you use the foam (try it with a piece of mouse pad) the contact surface where the edge touches the paper bends just a bit, creating a small curve.
Work both sides and you have two convex surfaces that cross each other.
This my friend, is a small sale version of what all knife makers world wide accept as THE best kind of geometry for a knife: The convex surface. Also known as appleseed edge, baptized that way by Bill Moran.
That’s the same principle you find in the old fashion leather and canvas strops. You apply tension, but when the blade touches the strap of material, you have a small curvature.
Again, this has been my humble experience. I’m very pleased with the results, so that’s why I encourage every knife user to give it a try.
Take care, and have fun!
Edited to add:
I’ll be damn... this is exactly what I was talking about. Thanks Dan ;)