Originally Posted by gonervn
The gap is actually a cut accross the width of the rv.
DOW makes a construction tape that we use on foam board before the application of siding. This is some very sticky stuff and is light weight. It's called Dow Weathermate Construction tape.
We use a different type of weather proofing tape around openings and it is very sticky also but would be more applicable to vertical application because it is thick bodied and heavy. It's DOW's Weathermate Flashing tape
I'd give the light weight tape a try, I know from expericence it sticks to most everything, even me. Don't use it if you're a wanted felon because it leaves a great finger print.
Stop by a construction sight where they are putting up foam board and ask if they might have a little left on a roll they might give you.