Corvette C4, Taking Care of Your Acrylic Targa Roof

Because of my background in plastics manufacturing, I get a lot of calls and requests about how to care for your C4 Corvette Acrylic Targa Roof. Basic roof maintenance goes a long way in increasing the life and appearance of the acrylic panel.

For a bit of history, when Chevrolet redesigned the Corvette for its introduction in 1984, they designed a lot of great ideas that were used in other sports cars in the past. Instead of the T-Top roof panels that had been used on the Corvette C3 from 1968 to 1983, they opted for a Targa roof like the one on the Porsche 911. The standard roof was a fiberglass panel painted the same color as the car. car. Chevrolet also had an optional sunroof that featured a smoked bronze or blue plastic. Lexan was originally used on the roof in 1984, but was found to scratch easily. Lexan is a very tear resistant material, but the drawback to its tear resistance is its soft surface which scratches quite easily. As a side note, all race cars use Lexan for their front windshields, from the local tracks to the Nascar Nextel Cup Series. In the Nextel Cup and Nationwide Series, race teams use peel-off films over Lexan that can be removed during the race, minimizing scratches on the windshield. Later, in the 1984 model year, General Motors switched to acrylic with a scratch-resistant coating to help prevent scratches on the roof.

Caring for an acrylic ceiling panel is easy. Wash the panel with mild detergent, Walmart’s standard car wash detergent is fine. The key is to give the roof a good spray with a hose to remove any loose dirt BEFORE WIPE THE SOAPY RAG. After the ceiling is dry, apply wax to the ceiling. It is important to NOT use a cleaning wax, repeat DO NOT use a cleaning wax as it has abrasives to clean dirt and oxidation on a car’s paint and will scratch the plexiglass roof. I suggest applying multiple coats of wax and applying frequently as the wax will burn in the sun.

Removing deep scratches from the ceiling is a bit more involved, but if you’re careful and cautious, it shouldn’t be a problem. You should first sand the scratch with 1200 grit sandpaper. Personally, I use wet/dry paper and wet sand the scratch with water mixed with a little dishwashing detergent. The water acts as a lubricant to help keep scratches on the surface caused by the sandpaper to a minimum. After this step, dry the area and clean it. If it is a small scratch, you can rub it by hand. Starting with heavy cut buffing compound, buff the area with a soft cloth. Then clean it with a finishing polishing compound until all scratches and shine are gone. The final step is to apply a few coats of paste wax to the ceiling. If the scratch is large, you will need to use a buffing wheel. Before using a buffing wheel, make sure you have experience with it. If not, I suggest you call an auto detailer in your area.

For fine surface scratches you don’t need to use sandpaper, just lightly polish the roof by hand with a scratch-removing compound, such as Maguire’s. It may take some time, so be patient.