Hey Big John,
The flat face of the paddle bit meets the beveled end to form a sharp cutting edge. After a number of cuts, that edge gets beat up. Since this is a quick and easy thing to sharpen, I won't go into a lengthy diatribe about how to sharpen plane irons, chisels and scissors.
Here are a few tips.
- Maintain the factory bevel angle as you re-grind the bevel on the end.
- Don't grind the scoring burr off the end of the cutting edge, if you have such a burr.
- Grind the bevel until the flat face and bevel angle meet again all the way across.
- Don't overheat the metal. It can get too hot, especially right at the very cutting edge where the steel is thin. Quench it in some water here and there so it doesn't heat up. You can remove the temper of the steel by overheating, which will leave you with a claylike drill bit that will last about as long as a drill bit made of Silly Putty.
- There should only be two angles to make your cutting edge: the face and the bevel. Don't try to put another little bevel on the face side of the cutting edge. That will ruin the cutting action.
- Since paddle type bits have a sharp point in the center and sometimes scoring burrs at the perimeter, it is a good idea to do that kind of job with a Dremel.
- Don't leave the bit with an overhanging burr on the edge. You can use a fine diamond stone to flatten the face of the paddle bit and take off that burr. Go back & forth, face and bevel, until the burr is gone.
Remember, don't re-grind new angles on the bit. As you study the bit and all of its angles, you'll see where the cutting edge is located. The cutting edge might twist and turn slightly around the point and burrs, so when you sharpen the points keep the factory bevel intact.
One more little concept to ponder. To get the sharpest edge possible, first flatten the face of the bit with a diamond stone and work your way up through the grits until it's flat and smooth. Then work it over for a while with red jeweler's rouge until it's like a mirror.
Now that the face is flat, grind the bevel, work up through the grits and polish to a mirror finish.
Now you don't need a drill. You can hand-turn your mirror-finish drill bit through 6 inches of bird's-eye maple.
I'm happy that I can now sharpen everything I own, including Xacto knives (most people don't know how to sharpen things that are already that sharp), razor blades, drill bits, planes, chisels, scissors, axes, serrated blades, screwdriver tips, hammer claws, table saw blades, circular saw blades, hand saws, band saws, etc.! NOW DEN!
I taught a female artist friend how to sharpen a chisel, I flattened both faces on an old set of scissors she bought at a garage sale to return them to like-new shearing action, but she keeps trying to get me to sharpen all her stuff. Be wary of trying to teach a woman how to sharpen things - they don't want to know how to do it. Don't let anybody know you know how to sharpen anything. If you meet the wrong person, you'll be strapped to the sharpenin' post from now 'til the cows come home.
