Can You Sand and Wax a Fiberglass Shower?

Clean the Surface

• Before you attempt to sand, wax or otherwise repair a fiberglass shower, you must thoroughly clean its surface. If at all possible, use the cleaner recommended by your fiberglass shower's manufacturer. If that product is not available, use a nonabrasive tub and tile cleaner. Rinse the surface thoroughly and allow it to dry.

Sanding

• There are many reasons to sand the surface of a fiberglass shower. The most common reasons are to repair cracks, remove stains, or to roughen the surfaces around cracks or holes before patching them. Sand fiberglass with extra-fine, fine or medium sandpaper. Extra-fine sandpaper is suitable for removing stains and surface abrasions or for roughening the surface to prepare it for adhesives or other coatings. Tackle deep scratches with medium sandpaper. Follow with fine and extra-fine grade sandpaper to remove the medium sandpaper's sanding marks.

Waxing

• A wax coating is ideal for protecting fiberglass from stains, soap scum and minor surface abrasions. To keep your fiberglass shower looking like new, add a new coating of wax once monthly. Tim Carter, home improvement expert and author of Ask the Builder, recommends using a high-quality automotive wax spray on your shower stall. Follow the label's instructions and buff the shower stall to a shine 15 or so minutes after the application.

The Floor

• Avoid getting any wax on the floor of your fiberglass shower. Wax is quite slippery. When on a frequently wet surface like the floor of a shower, it poses a significant slip hazard. If you must wax the fiberglass floor to protect it from stains, place a bath mat on the floor to reduce the slip hazard.