Many motorhomes, or recreational vehicles, are constructed from fibreglass -- a lightweight, durable material that will withstand the elements and requires little maintenance. In order to effectively paint a fibreglass motorhome, the area first must be properly prepped; this involves sanding the area, allowing the final coat to effectively adhere to the surface. The surface is then covered with a specialised gelcoat paint. This gelcoat paint comes in a variety of colours and is purchased in a two-part kit from a hardware or home improvement store.
Clean the entire outer 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 any difficult, higher surfaces.
Sand the entire surface of the fibreglass motorhome with fine grit wet sandpaper. Use a palm sander to make the job faster. Avoid concentrating on one area for an extended amount of time. The idea is to "roughen" up the surface, so that it will accept -- or absorb -- the primer and paint.
Wipe down the newly 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 was not cleaned away with the soapy water.
Tape off any area, such as door knobs, the windshield, and windows with painter's tape and heavy paper.
Clean out 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 fitted with a primer nozzle.
Mix the gelcoat in the correct ratio according to the package directions. The gelcoat will come in a two-part process that involves mixing the colouring agent with a hardener that is mixed inside of a plastic bucket. The mixing should occur no longer than 10 minutes before the painting will occurring to ensure that the gelcoat does not begin to prematurely harden.
Fill the paint gun reservoir with the mixed gelcoat and begin to cover the surface of the motorhome using long, even strokes to avoid any runs or drips. Begin at the front of the motorhome and work your way to the back to provide a more even appearance.
Allow the first coat of gelcoat to dry for 24 hours before applying a second coat. Once again, use long even strokes to avoid any runs and check your work to ensure that every area is covered with an even layer of the gelcoat.
Allow the final coat to dry for 24 hours. Any uneven spots can be cleaned up carefully with piece of fine grit sandpaper.
Apply a single coat of motorhome or RV wax with a soft cloth. Work the wax onto the surface of the motorhome in overlapping circles. Allow the wax to cure for one minute, or according to package directions, before buffing it away in overlapping circles with a soft cloth. This will provide a protective shine to the newly finished gelcoat.
Remove the painter's tape and heavy paper carefully.
Work in a well ventilated area and wear a face mask and safety goggles when sanding and applying the gelcoat.