Drilling a hole on a curved surface, such as molding, can be tricky because the bit has a tendency to wander. To keep the bit centered first use an awl to punch a hole where you can plan to drill.Then start drilling the whole with the bit perpendicular to the surface. Once the bit takes, swing it gradually to the proper angle.
At the joint
masking tape is an ideal guide for drilling into dado and butt joints. The tape should be the same width as the end of the work-piece(for example, a shelf or a partition in a stereo cabinet) that butts against the face of the other work-piece. Lay the tape across the work with the ends overhanging and lining up with the perpendicular piece. Mark the hole locations on the tape and begin drilling when you remove the masking tape. You’ll find that the wood will be less chipped than usual.
Here’s how to make a handy two-in-one jig for guiding drill bits. Cut a V-groove in each end of a scrap block of wood. One groove should be at a 90° angle for drilling perpendicular holes; the other one at another commonly used angle such as 45°. Use the jig to start the drill bit at the desired angle, then remove it to continue drilling.
Drilling holes for shelf pins is a snap with this handy hole spacing template. Cut a strip of peg board 3 to 5 holes wide and long enough to cover the height of the work. To avoid drilling too many holes, cover every other row of the holes with tape. Because the lower shelf normally starts 200 mm from the bottom, you can also cover the bottom 200 mm holes with the tape. Label the top end of the template so you don’t accidentally position it the wrong way around. Secure the template flush to the edge of the work with spring clamps. Then start drilling through the center strip of holes.
A bit of a trick
When drilling through some wood and all plywood, the bit may chew up the exit hole unless you drill the hole part-way on both sides. A faster and neater method is to back up the work with a piece of scrap wood. The bit will chew up the scrap not the work.
Hole in a hole
Centering a drill bit can be difficult when you’re enlarging an existing hole. The solution is to first fill the hole with a same-size dowel or plug (which can be made with a hole saw). Punch the center of the dowel or plug with an awl; then used the punch mark to center the spade bit for the larger hole.