Hi Dave
I would say that yes it is probably delamination and it is very expensive/hard work to repair properly, the skins have separated usually through water ingress so the cause of this ingress needs to be addressed!
As regards the delamination you have some how to glue, screw or clamp the skins back together which involves drilling holes and injecting glue/resin into the void and somehow pushing the expanded skin back in and allow the glue/resin to do its work. if the area is small you can sometimes get away with say bolting the skins together and hiding the bolts with a plastic vent cover which would not look out of place!Another way would be to park next to a solid object and jack off this so as to push the wallskin back in then of course body work and painting is required unless you can get at it from inside the RV, either way it is a lot of work.
Of course the other way is to replace the whole/part of the panel!
Found this on The RV Forum:
Materials
# Finishing resin and hardener. This has a lower viscosity than epoxy resin used for normal fiberglass projects.
# A large syringe for dispensing the resin.
# A panel board large enough to cover the delamination area.
# Some lengths of 2x4.
# Several wedges.
PdurerocePark the RV next to a wall or rigid fence.
Drill holes along the top of the delamination area and then alternate spaces going down to the bottom of the delamination. Using the large syringe, inject the finishing resin into the top holes until it starts to appear at the holes below. Continue injecting resin and moving down the delamination area until the bottom holes are showing the resin coming out. You can wipe off any excess while applying pressure to the RV wall.
Place the sheet of plastic over the delamination area, followed by the board, then wedge the board against the repair using the lengths of 2x4 and wedges. Allow the resin to cure overnight.Also see here
http://rv-roadtrips.thefuntimesguide.co ... nation.phpRegards Pat