Modified Mustangs & Fords
Fiberglassing Body Parts - Pain In The Glass
Fiberglass Parts Fitment Takes Patience, But The Results Are Worth It
In beginning our bodywork phase of our Generation Gap project '68 fastback, we knew we had plenty of fiberglass parts and modifications to tackle on our car. From installing a Shelby-style trunk lid and endcaps, to custom lower sidescoops, a multi-piece ground effects kit, and a one-piece nose, we had our work cut out for ourselves. Our fastback's bodywork is being handled by the crew at Classic Creations of Central Florida, not far from our offices. CCFL has worked with us before on numerous paint and body projects and we trust its work. From stock restos and mild customs to full-blown modified cars like ours, we've seen the company tackle it, so confidence in handling our fiberglass work was not an issue. Check out the beginnings of our bodywork here and tune in for more in an upcoming issue where we'll actually lay color and move forward with final suspension and drivetrain installation, wiring, and more. Don't worry; we've got plenty to cover, including some never-before-seen upgrades we think you'll want to see.
What You'll Need
There are different types of fiberglass, resin, and hardeners available to the end-user. Buying the cheap stuff at your local Wal-Mart might be OK to build a speaker box, but for bodywork that you want to last, head straight to an auto body supply house for the good stuff, especially the resin. A good quality resin will pour like warm syrup or thin motor oil. The cheap stuff usually has the consistency of molasses and takes much longer to dry. You also want polyester resin, though that's pretty much what's sold these days anyway.
For the fiberglass there is mat mold and woven cloth, and several thicknesses of both. Mat mold uses a random pattern to its fiberglass strands where as the woven, as its name suggests, is a weave of strands with a definite pattern to it. The mat mold is easier to hide in bodywork (you can sand down to the woven cloth and see the pattern in your body work) but the woven cloth is stronger. It all depends upon what you are building and where on the car. Fiberglass is very forgiving. You can sand it, mold it, cut it, and more. Best thing is, if you mess up you can simply cut it off and start over.
You'll need hardener for your resin. The mix ratio is usually 15-20 drops per ounce of resin, but it can vary depending upon working temperature. Sometimes you want to mix the resin "hot" for it to set up fast. But remember, the hotter you make it the more brittle it becomes. For a strong and effective repair you need to use the right mix. You might even want to make small sample batches of resin and take notes as to how quickly it sets up. The working environment needs to be warm, but if it is too difficult to heat your whole garage-use portable heat lamps or a heat gun for small localized areas.
Finally, grab some disposable gloves, acid brushes, paper respirators for sanding, an old long-sleeve shirt, and you'll also need a mixing bowl for the resin. A good idea is an old Tupperware container, as you can flex the plastic bowl and "pop" the dried resin out of it to reuse it again. Whatever you do, refrain from using wax paper cups, as the wax will leach off into your resin and cause all sorts of scary issues you don't want to deal with.