Simple process to repair plastic interior panels with epoxy resin and fibreglass cloth.
I’ll post a couple pictures of a recent repair I just did on one of our aircraft. The before door image shows a piece missing and if you look closely you will see the plastic panel is actually cracked in a couple of places and the only thing holding the panel together is the door frame.
The other interior trim piece was broken into three parts and the centre had a missing section that was long gone.
I use EPOXY resin and fibreglass cloth usually 7781 from spruce but you can go to your local fibreglass shop a purchase a light weight glass cloth.
Usually I hot glue the pieces back together and sometimes if the parts are really damaged I glue them to a board or the bench top with hot glue to hold them in place. Hot Glue the parts on the exterior side (the exposed side you see in the aircraft). For the missing areas use what ever you require to make the shape of the missing area. I use foil tape as my first alternative because you can rub a little mould release wax on the tape and the epoxy won’t stick to it. I’ve used cardboard, tape, plastic from containers, aluminum foil, believe it or not one of my best products for complicated shapes is PlayDo. What ever it takes to hold the shape required. Also I use epoxy resin over other resins because it adheres to the plastic better than vinyls or polyester. When the part cures you can touch up the front side with a little body filler or epoxy resin and q-cell mixture. Than off to the local auto store to pick up a spray can of whatever paint that matches the finish required.