Hi Bill,
Although the hole in your trailer is in a bit of a bad spot it looks to me
like the seam is not so close that aluminum tape can't be applied. It would
only require a small piece of aluminum tape. I've used it in a few places
where the hole is too big for a rivet, but too small for patching with
Alclad.
First, gently remove burrs to make the edges fairly smooth. Clean the
surface around the hole with acetone to remove all oil or polish. Then,
since you can get to it from the inside, apply a piece of aluminum tape to
the inside, getting the edge of the tape up into the thin gap between the
rib and skin as much as possible. Then cut a small piece of aluminum sheet
to the same dimensions of the hole and place it in the hole just to act as a
spacer. The tape on the inside will hold the spacer in place. Then apply a
small piece of aluminum tape to the outside, again getting the edge up to or
even into the seam above as much as possible. Then seal the seam with gutter
seal (or whatever you use to seal seams) where it meets the tape just to
make sure it won't leak.
The tape can be removed and repositioned (or redone) provided you don't
press down on it or leave it in one place for too long. The adhesive becomes
more permanent as time goes by and is water proof.
The hole in my trailer I taped five years ago is still in good condition and
doesn't leak. It blends in so well that no one has ever mentioned it to me,
so I assume it hasn't been noticed. It can even be polished (gently). Just
make sure the edges have adhered well and that the tape doesn't have any
puckering. Total cost for this kind of repair is negligible and shouldn't
take more than a half hour or so.
Forrest