How to align a hole drilling through a wall
How to align a hole drilling through a wall and locate identical positions on opposite sides of a wall using a bar magnet and pocket compass.
The magnet, attached to a suction cup, holds the position on one side of the wall. On the other side, a compass points to the magnet so the spot can be marked.
A couple of tips.
On smooth surfaces use masking tape or electricians tape to help reduce “drill slip”. Just make sure that the tape doesn’t have any adverse reaction to your finished surface when you remove it.
Start holes off with a Bradawl or similar (a nail would do) to make sure you are at dead centre. Drill out an undersized hole at a low-speed to allow accuracy. Check these holes with a level and then drill out to full size. Should the hole need adjusting up or down you can do this when drilling out to full size by angling the drill in the appropriate direction for a couple of seconds when starting to drill out to full size.
On most power strips and mountable speakers, light strips, and pre-fab shelving etc. The holes where the mounting screws slot into the body are on the back. This keeps the screws out of sight, but it also makes it more difficult to visually align the screws when you’re doing the actual drilling.
Here’s a trick: Use a piece of masking tape and have the holes line up perfectly every time.
First, place a strip of masking tape along the back of your power strip or other item that needs to be mounted. Use the edge of the power strip as a guide to the area around the mounting hole is usually raised and you can use your finger to help find the exact center of the mounting hole. Use a thumbtack to poke a hole through the center of the mounting hole or a pen to mark the area.
Remove the tape and place it on the wall where you want to mount your power strip. Now you can drill the screws directly into the marked area on the tape. Drill your screws in, remove the tape, and mount.