How To Refinish a Therma-Tru Door

Cover the flooring under your work area with a plastic sheet or drop cloth. Remove the door from its hinges, starting with the bottom hinge and working to the top. Set the door on two sawhorses.

Remove all the hardware from the door, including the knob, hinges and any locks. Set the hardware aside in a safe location.

Cover any glass windows with painter's tape. For large windows, use plastic and painter's tape around the edges.

Apply a methylene chloride-based stripper to the door by spraying it onto to the door's surface using the spray bottle that comes with the stripper. Allow it to sit for 20 minutes. It gels as it works.

Scrape the stripper off the door using a synthetic scrub brush.

Apply a second coat of stripper and allow it to sit for 20 minutes. Scrub it off with a brush.

Wash the stripper away using dish soap and hot water. Scrub with a synthetic scrub brush.

Wet a rag with mineral spirits and wipe the door to remove any residue.

Stir the stain and dip a rag into it.

Stain the door by rubbing the stain in a circular motion over the fiberglass sections. Therma-Tru recommends the door be stained in orderly steps. Start with the door frame, continue with the interior panels and interior flat sections, then the glass frame, and finish with the exterior flat sections. Use a foam brush to work the stain into any deep grooves in the door's surface.

Wipe the stain in one direction after the door is thoroughly coated. This gives it an even appearance.

Allow the stain to sit for 10 to 15 minutes. The longer it sits, the darker it gets.

Wipe a clean rag over the stain to remove any excess. Work with the door's grain.

Fan a 3-inch bristle brush made from natural fibers over the stain to ensure the door is evenly coated. The bristles work into even deep grooves.

Allow the stain to dry for at least six hours.

Apply topcoat with a damp 2-inch bristle brush in the same order in which you applied the stain. Apply a thin layer so the topcoat looks wet instead of milky.

Let the topcoat dry for three hours. Apply a second topcoat.