How to Seal a Camper Shell

Prepare the area where the shell meets the rails of the truck bed. This involves cleaning and degreasing with industrial grade solutions. Products like Simple Green or brake cleaner work well for the cleaning process. Make sure to remove all debris, dirt and grime from the bed rails. Do the same for the camper shell surface that seats against the bed rails. Remove any old weather stripping or glue that may be present on either surface. While it is not necessary to prime and paint the surfaces, it can make for a better seal in the long run.

Apply rubber weather stripping to the camper shell. Weather stripping can be found at most auto parts stores and is usually quite inexpensive. It will also be necessary to purchase weather stripping glue in order to apply it to the camper shell. Apply a nice solid bead of glue on the surface of the shell and carefully stick the rubber stripping on. This glue dries rather quickly and is very sticky, so make sure the stripping is even on the shell right away, because there won't be an opportunity to adjust it later.

Seal up any gaps in the camper shell body. Some shells come with windows that open, doors in the back, or even sun or moon roofs. If the interior is to stay dry and clean, these openings must be sealed as well.

You can find leaks by squirting a garden hose at the shell while observing the inside for any water that may penetrate. If you find leaks, simply apply RTV silicone (from the auto parts store) or caulk to seal things up nicely and neatly. Just apply a thin but solid bead around the leak (after it is dry) and let cure. Retest the seal after a few hours to see if the fix worked, and recheck for more possible entry points.