Dings in fiberglass bumpers and doors are inevitable. Most small dings that you pick up over the years are hardly noticeable at first. However, over time they can grow and become problematic, leading to paint chipping and compromising the shape of the fiberglass. By using a simple fiberglass repair kit (along with a few other supplies) you can patch small dings before they become a serious problem. This article explains how to repair fiberglass sections of a car using a simple kit. You don't need to be particularly handy or proficient with auto repairs to handle this project.
What the Kits Include
Most fiberglass repair kits don't come with the essential supplies for simple patch jobs. They include the fiberglass cloth, resin, liquid hardener, a mixing stick, and a tray. In addition to these kit items, you will also need a plastic putty knife, masking tape, autobody sandpaper (extra fine grit), and normal scissors. Some kits come with a plastic spreader, but these are usually very flimsy, and you will do much better if you have an actual putty knife with a handle.
Prepping the Area
To begin, you might need to sand the are that is dinged. There might be chipping paint around the ding. Sanding will knock down any loose edges, but you don't want to actually sand through the paint. Just lightly sand until the area is smooth. Next mark off the perimeter of where you want to patch with the masking tape. This tape is just a guideline, but it will be helpful when you are spreading the resin and controlling the mess. Then, cut the cloth to size. You want the cloth to be about an inch larger than the ding on each side.
Mixing and Spreading the Resin
The fiberglass resin needs to be mixed with liquid hardener before it is applied. The resin dries quickly once the hardener is added, so make sure your prep work is completely done at this point. Use the putty knife to spread the resin over the cloth as you hold it in place. Try to spread it over one corner or edge as you hold the other side. Once enough resin is on the cloth, it will hold. Spread the resin as thinly as possible and then let it dry. Then you will probably need to apply a second coat that fully covers the texture of the fiberglass cloth. Once the resin is dry, you can use the sandpaper to lightly smooth out the surface ad make the texture blend in.
Just like that, your ding will be fixed and reinforced. You can rest assured that the ding will not grow bigger and become problematic.
For more information or to fix more serious problems, visit an auto repair shop.