Q. How do I install a peephole in a fiberglass door?
A. Fiberglass doors are built with two fiberglass panels with wood blocking and insulation at the core. You can drill through these materials to install a peephole. Most peepholes require 1/2 in. hole. Locate the peephole in the center of the door and approximately 58 in. from the bottom. Start with a 1/8-in. spiral bit at the center of the peephole location. Run the drill at full speed and press lightly to bore a clean hole through the fiberglass and into the inner foam core. Drill through the insulating core and through the fiberglass panel on the other side. Switch to a 1/2 in. spade bit. On the inside of the door, insert the tip of the spade (or hole saw) into the pilot hole and drill your peephole. To reduce chipping the exterior, stop drilling when the tip of the bit begins to penetrate the exterior fiberglass panel. From the outside, place the larger drill bit into the pilot hole and drill through the exterior panel, completing the hole. Dab the drilled holes with sealant or epoxy. Unscrew the “door viewer” or peep-hole assembly into two sections. Insert one section into each side of the hole made in your door, making sure the appropriate lens is on the correct side of the door. Twist the pieces together to tighten.
