Detailed answers for wood drilling questions
Drill perfect holes in wood with no tearout
There are two method to drilling holes in wood with no tearout based on precision. (1) Fine woodworking applications use a backer board. Clamp the workpiece and the backer board together. Select a good-quality bit with a starting point and side cutters, such as a forstner or brad point bit. Forstners and brad points drill more precise holes than standard twist drill bits. The bit treats the two clamped pieces of wood as a single piece; as the drill bit passes through the workpiece and into the backer board you won’t get tearout on the workpiece. (2) Non-precise holes can use a spade bit to drill the hole. When you’ve just about pierced the backside, stop and flip the workpiece over. Use the hole pierced through the backside of the workpiece as a centering guide, and finish the hole from the backside.
Remove pitch build-up from wood boring bits
After extended use in gummy or sticky wood, a wood boring bit can become coated with wood pitch. Pitch build-up causes the bit to drag, which can burn some hard woods. Any number of commercial products are sold that can clean and help prevent pitch buildup on bits and blades. Spray-on oven cleaners can do the job. As an alternative method, you can fill an empty coffee can with just enough paint thinner or de-natured alcohol to cover the bit. You MUST place a cover on the container, as solvents are flammable. Soak the bit overnight. Use a soft brush, such as a toothbrush, to get rid of any remaining residue, then wipe clean with a rag.
Drill holes in curved surfaces like molding
Here’s a suggestion for drilling a hole on a curved surface, such as molding. First, use an awl to start the hole in the exact location you want it on the workpiece. This minimizes the possibility of the bit “walking” or “skating” across the workpiece surface when you start to drill the hole. Next, using a twist drill bit, hold the bit perpendicular to that part of the curved surface of your workpiece, and begin drilling to a very shallow depth, no more than 1/8”. Once you get the hole started, sweep the bit into position so that it is parallel to the hole you are drilling. Then continue drilling to the desired depth. When finished, the hole will not be completely round, so you might want to use wood putty to plug the uneven hole.
Enlarge or “move” a pre-existing hole in fine wood
For enlarging or “moving” pre-existing holes up to 1” in diameter, one option is to plug the existing hole with a dowel and then re-drill it. Dowels are available in 1/8” increments. Select a dowel that fits snugly in the hole; you should find it necessary to tap it in using a plastic or rawhide mallet. If the hole does not fit one of the dowel’s dimensional sizes, use a larger dowel and taper it to fit the hole using sandpaper. Next, select a good-quality bit with a starting point and side cutters, such as a forstner or brad point bit. Forstners and brad points drill more precise holes than standard twist drill bits. Use a drill press and make sure the workpiece is clamped down to prevent wobble and inaccurate drilling. Drill the hole to your desired depth.