Fastening towel bars, shelves or hooks to a fiberglass or plastic shower surround can be tricky. How to Permanently Anchor a Bathroom Towel Bar. Your grab bars will be rock-solid if you anchor them to studs.
We'll show you how to mount grab bars to fiberglass tubs and showers, hollow walls and concrete . The Solid Mount is the only Mounting Bracket designed specifically for fiberglass Showers and Tubs allowing a grab bar to be installed into your fiberglass . Handicap handle on fiberglass shower enclosure (post #187991). The top mounting screw holding my glass door unit to the fiberglass.
I've considering using a anchor style screw along the lines of what I . I can just attach it to the fiberglass or I need to somehow find structure behind. Here's a link which shows the different anchors made by WingIts. SecureMount Anchor mounting plate is made of stainless steel.
Moen's Secure Mount Anchors can help your towel bar hold.