I'm trying to decide what to do inside my for rustproofing. When I
pulled up the floorboards I had some very minor surface rust under
them, likely due to moisture from wet feet camping, my ocassionally
leaky skylight, etc. Since I am going to laying soundproofing on the
floor I figure that the only effective way to stop moisture from
reaching the floor metal is to take the entire floor down to bare
metal and Por-15 it. Then lay the soundproofing over top.

Where I am having trouble deciding on a rustproofing solution is on
the side panels. While I could (with obviously considerable effort)
also take the side panels down to bare metal and Por-15 them I am
worried about drainage, condensation, and seam rust. Here I think I
will not soundproof the exterior metal panel but instead soundproof
right behind the cardboard & vynal panel (or whatever VW makes those
things out of) see:

http://www.b-quiet.com/vanagon2.html

http://www.b-quiet.com/vanagon.html

Soundproofing behind the interior panel will allow any rustpfoofing
sprayed in there to reach all the body metal, and possibly seep into
seams, etc. Wheras if I Por-15'd it I'm worried that the rustproof
spray would not be able to flow as freely (plus I just can't por-15
the entire cavity, I would not be able to reach every single spot -
some hide deep behind metal.

For similar reasons I am seriously considering removing ALL fiberglass
insulation from the body cavity. I do a reasonable amount of cold
weather camping so I wish there was an alternative here but I feel
that any insulatrion here would both trap water and inhibit a sprayed
rustproofer from making its rounds through the body cavity. I may cut
foal insulation to fit and secure it to the interior panel so it is
not contacting metal (this will leave LOTS of gaps, but at least its
something).

Thoughts?
Chris