I know from past experience that many if not all campers eventually develop leaks
recently I picked up a nice older aluminum truck cap/canopy/shell to build out into a small camper. It's taller than cab height, with a sloping frontside, 2 big sliding windows, and a huge clear glass window. I insulated it with 1/2 inch foam, then screwed & glued 1/4 birch ply on the walls, with carpet-covered luan on the ceiling
just took it out for the maiden voyage up to the white mountains where it was POURING rain for a good 12 hours, like torrential, can barely see style. got in the camper that night & noticed water coming down the inside wall pretty steady
I'm thinking that it might be the one center seam on the roof of the shell. that's the only seam up there and it may have been tweaked slightly when I screwed the walls into the square tubing framing
am trying to figure out the best fix...have read about people using JB weld, dicor, silicone, and roofing tape. I am eyeballing the Gorilla Waterproof Patch and Seal Tape and also the Eternabond RV Tape. both are uv-rated and made specifically for mobile/roofing applications
does anyone have any experience with this type of fix?
I used 3M's Extreme Sealing tape to seal around the edges, roof fixtures and front seam on our older Class C. This is the same tape they use on the 300+ kph bullet trains in Europe. It isn't cheap but it sure does what it is designed to do. Pretty easy to install and once it is down, it is down for good. I'd hate to be the guy to remove it.
Any single hole can leak. So can window frames, roof hatches, mounting holes of roof racks ... anything. You do not need a big hole, just water on the outside and gravity.
If it is an older aluminum roof, it could also be corrosion pinholes. Barely visible from the outside.
With your description, it is hard to tell whether there are other potential candidates. A picture or two would help.
2014 Ford F350 XLT 6.2 SCLB + 2017 Northstar Arrow
You didn't say how the seam is made up . Does it go front to back or side to side ? Does it overlap or butt with molding ? Adhered together , screwed or riveted . Are there any other protrusions through the roof . If water is coming down the wall it could also be the seam where the roof meets the wall .
As the above recommendations are good and eternabond tape work great as I have it on my own camper,if the entire camper is aluminum you may want to try the aluminum type tape that they use for HVAC installs. It holds Very well and won't look to "Redneck" worth a try.
Eternabond works great. Appearance is/can be questionable, depending on how visible it will be, what color it's going over, and how much you care about how it looks.
All the tapes are not only tricky to apply, but look redneck. Your aluminium plates should have sealer between them, so patching the leak on the surface will be ... patching. Anyway, I tried lot of caulks and even the expensive marine grade don't hold on long term. The best choices would be dicor in clear, or OSI QUAD Quad if you want color.