Dear Tom and Ray:
I have a '92 GMC van that features a fiberglass roof. The problem is that the roof has two rather large holes in it due to a lower-than-perceived concrete support beam in my local shopping mall's parking garage. I need a cheap, relatively easy way to patch this up. Friends have recommended using sheet metal screwed into the fiberglass and sealed with caulk, but I'm a bit worried that I might end up cracking the fiberglass even more with a series of screws. Any recommendations? -- Trent
TOM: I wouldn't mess around with sheet metal and screws, Trent. You can caulk it all you want, but by putting more holes in the fiberglass, you're exponentially increasing the potential for future leaks.
RAY: Fortunately, there are other ways to fix fiberglass. Lots of boats are made of the stuff, and it's a very repairable substance. There are patch kits on the market specifically made for repairing holes in fiberglass.
TOM: You can get them almost anywhere, from marinas to auto-parts stores to the automotive section of department stores.
RAY: They usually come with a piece of mesh that covers the hole. Then you spread epoxy over the mesh and let it dry. And voila! Half an hour later, no more hole. Then, if you care how it looks (I'm guessing you don't, since you're considering sheet metal), you can sand it and paint it to match the original color.
TOM: If it's good enough to keep water from penetrating a boat hull, you know it's good enough to keep the rain off the shag carpet in your van.
RAY: You might need several of these kits or even a case of them, Trent, depending on how big your holes are. If you run into questions, try your local marina. They've probably got more experience fixing fiberglass than anyone else.