Things You'll Need
1/4-inch drill bit
If you want to install a new fiberglass shower or change the plumbing in your existing shower, you may need to cut a hole in the shower wall. Using dull tools or poor technique can cause the fiberglass to crack around the hole. Here are a few tips that will ensure a clean cut.
Decide where you want to cut the hole and draw a circle with a marker. Draw a dot to mark the center of the hole.
Put masking tape around the circle to prevent damage to the surface of the shower wall.
Drill a hole in the center of the circle using the 1/4-inch drill bit. Take your time drilling the hole to avoid damage. This hole will assist you when using the hole saw.
Match the hole-saw blade with the circle on the shower. The center of the hole-saw blade has a drill bit. Insert this bit in the previously drilled hole to help keep the saw steady.
Press the saw blade against the shower. Lightly press the power button to start the drill. Do not go faster than medium speed and drill through the wall slowly. If you try to force the saw blade through, you risk cracking the fiberglass.
Use the finest carbide-tip saw blade you can find. If it has several tiny teeth as opposed to large teeth, there is less of a chance of cracking the fiberglass.
Wear gloves, safety glasses and a dust mask when working with fiberglass.