Many motorhomes, or RVs, are built from fiberglass – a lightweight, durable material that will withstand the elements and requires little maintenance. To effectively paint a fiberglass motorhome, the area must first be properly prepped; this involves sanding the area, which allows the final coat to effectively adhere to the surface. The surface is then covered with a specialized gelcoat paint. This gelcoat paint comes in a variety of colors and is purchased in a two-part kit at a hardware or home improvement store.
Clean the entire exterior surface of the motorhome with soapy water and an automotive sponge. This will remove any dirt, grime or animal droppings from the outside of the unit. Use a ladder to reach all difficult, higher surfaces.
Sand the entire surface of the fiberglass motorhome with fine wet sandpaper. Use a palm sander to get the job done faster. Avoid concentrating on one area for a long period of time. The idea is “roughened” to the surface, so it will accept – or absorb – the primer and paint.
Clean the freshly sanded surface with a rag and denatured alcohol, which can be purchased at hardware or home improvement stores. This will remove any remaining grease that won’t be cleaned away with the soapy water.
Tape off any areas such as doorknobs, windshields and windows with painter’s tape and heavy paper.
Clean the inside of a paint gun with a soft cloth and acetone. This will ensure that any paint from a previous job will not mix with the gelcoat. The paint gun must also be equipped with a primer nozzle.
Mix the gelcoat in the correct proportion according to the instructions on the package. The gelcoat will come in a two-part process that involves mixing the coloring agent with a hardener that is mixed inside a plastic bucket. Mixing should take longer than 10 minutes before painting occurs to ensure the gelcoat does not start to harden prematurely.
Fill the paint spray gun reservoir with the mixed gelcoat and start coating the surface of the motorhome using long, even strokes to avoid runs or drips. Start at the front of the RV and work your way to the back to provide a more even look.
Allow the first coat of gelcoat to dry for 24 hours before applying a second coat. Again, use long slicks to avoid runs and check your work to make sure each area is covered with an even layer of gel coat.
Let the final coat dry for 24 hours. Any uneven spots can be carefully cleaned with fine grit sandpaper.
Apply a single coat of motorhome or RV wax with a soft cloth. Work the wax over the surface of the motorhome in overlapping circles. Let the wax dry for a minute, or according to the package directions, before buffing it away in the overlapping circles with a soft cloth. This will provide a protective shine to the newly finished gelcoat.
Carefully remove painter’s tape and heavy paper.
Tips and Warnings
- Work in a well-ventilated area and wear a face mask and goggles when sanding and applying gelcoat.