babs,
I assume you are talking about using the knife sharpener on your stingers.... If so, take a sharpie and mark the bevels good. Then set your angle on 22-25 degrees, not critical. Then take the coarsest stone you have and grind back and forth till you get a good bevel full length on the stinger on the first side. Once you have that done, flip and do the same to the second side. By this time you should have a burr full length that you can catch with the tip of your nail. Now all you need to do is go thru the grits polishing the bevel and edge you have established. When you get down to the fine stone change to a push only stroke, in other words push the stone up and into the blade 1-2 strokes, then flip. After a few times back and forth you will have one sharp stinger !!!