I did exactly what I wanted to avoid - I chipped the exterior wall when installing shelving on the interior of the trailer.
I carefully measured the length of the hollow-core door anchors in comparison to the gap between the interior and exterior walls. After installing one anchor I checked the outside wall and all was good. Then I merrily installed the others and used the screws that came with the anchors. Bad idea.
While the anchors are okay to use, the screws are not. I didn't drill all the way through the wall but I did chip or dimple the exterior gel coat on every screw.
What hope do I have of repair, if any?