I have been sharpening my own Mora blades and those for my buddy for years without issue. I typically only sharpen one side unless absolutely necessary to do both. I have about four sets and just rotate through them when they start to feel dull. I am sure they don't cut as well as new or professionally sharpened blades, but quite frankly they seem to work pretty well. I use a whetstone, maintain the exact angles that are present (to the best of my ability by hand), and just take off enough material to remove nicks and reestablish a sharp edge. I also make sure to never bang the blades down vertically to remove ice build up and I keep the guard on when not in use. I typically drill (by hand) 50 holes or so in a day of ice fishing and can get at least five days of fishing before I start to notice I am working harder (250 holes). You start to really notice dull blades when the ice gets past 8" thick.
