The problem with simply filling holes is that there *may* not be anything back there to fill and nothing for the epoxy to stick to.
I had the exact failure (As have many others) on my 13 footer a few years ago.
Unfortunately, all the pics and story were lost in the hack.. I will try to recap so it makes sense without the visual.
The raised area that the hinge mates with does indeed hide a plywood backer that the screws mount into. Unfortunately, it isn't an area folks pay much attention to when checking for leaks
, as the whole "Bubble" there is sealed off from the rest of the rig.. if there is a leak, you wouldn't know it...until the door falls off. Why Burro
didn't encapsulate the plywood, I dunno.. and it has caused this problem for many future owners. Once the water starts, the plywood backer literally disintegrates.. nothing left but powder if it goes too long.
What we did to fix mine:
Cut away the raised area, in one piece.. (After removing the door, of course) I used a dremel tool, it makes a clean cut for the eventual reuse of the bit. Save that sculpty bit as a whole (Think Skull Cap) and set aside for reuse. You will now see what has no doubt turned into a black powder.. that used to be the plywood block.
Vacuum out the cavity and roughly shape a bit of wood so it fills most of the space. Encapsulated the wood in fiberglass.. small kits are available at any auto supply store. Place wood in the cavity.
Next, get the "Hump" you cut away and fiberglass it back into place. Sand and fill as required around the edge you glassed back on.
Use stainless screws, and yes, when you remount the door, use epoxy in the holes.
When I sold the unit, the guy that bought it had no clue it had been rebuilt in that area. It isn't hard to do, you will have some paint
and refinish work to do tho.