i have a method for sharpening recurves using a pringles can.

take a pringles can with the bottom cut out and attach some abrasive paper to it. crimp down one side so you have somewhat of a square corner so you can sharpen the plunge line area of the blade. you put your arm through the can with the flat facing the knife for each side. match up the angle by tilting the blade and slowly push the blade away from you while working your way to the tip where you will stop. dont let the tip slide off or you'll round off the tip. switch the can to your other arm and repeat. once you have a burr worked up, go to a strop or ceramic stick to remove the burr.

for some recurves i use my belt sander or my paper wheels. i always finish off any edge with the slotted paper buffing wheel which gives me a razor edge.