How to Re-Drill a Bowling Ball

Many bowlers prefer to have their own ball rather than using the balls available at the bowling ally. In some instances -- buying a ball from someone else, or inheriting one -- you may have to re-drill the holes to fit your fingers. Plugging the old holes with liquid resin compound and drilling new ones provides a fresh, custom fit that gives the ball a whole new feel, optimized for your finger size and grip.

Things You'll Need

  • Liquid resin
  • Hardening agent
  • Plastic cup
  • Mixing stick
  • Electric sander
  • Balling bowl drill press
  • Bowling ball quarter scale
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Instructions

    • 1

      Clean the ball. Wash and wipe down the exterior surface of the ball and use a drill buffer to clean the inside of the existing finger holes. Inspect the ball afterward to make sure you have a clean, dry surface to work with, especially inside the finger holes.

    • 2

      Mix the plugging compound with which you will fill the existing finger holes on the bowling ball before drilling. Use a bowling ball compound that consists of a liquid resin and a hardening agent. Find a compound made by your ball's manufacturer to more closely approximate the original density of the ball core. Mix the liquid resin and hardener in a plastic cup, then pour into the finger holes of the ball until completely filled.

    • 3

      Wait for the liquid resin to dry and harden. Place the ball on a bowling ball stand or holder and let the plugs dry for a minimum of 24 hours.

    • 4

      Sand the top surface of the resin plugs. Use a handheld Dremel tool or similar sanding device to smooth over the surface of the plugs. Use small sanders so that the sanding won't overlap the plugs and damage the ball's surface finish.

    • 5

      Measure the thickness of the bowler's fingers to determine how large the holes should be. Bowling ball technicians use a device with various sized holes in it, similar to a common ring sizer. By placing the thumb and other two bowling fingers through the holes, it is possible to get a precise measurement of how large the circumference of the holes should be.

    • 6

      Measure the natural pitch of the bowler's thumb. Hold your arm up and ask the bowler to grab your wrist with the hand he or she uses for bowling. Measure the angle that the thumb lays at naturally, and make note of the angle so that the pitch in the bowling ball can be made to match.

    • 7

      Place a mark on the ball to represent where the thumb hole will be drilled, then lay a bowling ball quarter scale on top of the ball. The quarter scale is sized to sit perfectly on top of the ball, and allows you to draw perfectly straight lines in any direction. Using a grease pencil and the quarter scale, measure away from the thumb hole to mark the position where you will drill the other two holes.

    • 8

      Place the ball into the drilling machine and clamp it into position. Do not attempt to drill the bowling ball with a standard home drill press. You must use a bowling ball drill press, which is designed specifically to cut holes at various pitch angles. Lower the drill bit into the ball to re-drill the thumb hole first. Reposition using the laser guide and drill the subsequent holes, using the appropriate drill bit size. Re-drill through the plug material as much as possible, to keep most of the original ball material intact.