I have removed the bronze/brown residential shower skylight that Foretravel has used on many of their coaches, because the caulking failed and water leaked into the roof causing a delamination. I have made a replacement skylight using wood, epoxy, and fiberglass. It's basically just a laminated wood frame slightly larger than the opening. Laminated using the roof as the mold for the curve. Has 2 sheets of translucent plexiglass (should have used lexan) fastened to the top. Top piece is 1/4" and bottom is 1/8" thick with a ½ inch thick wood spacer between the 2 sheets of plexiglass for a double pane window effect. The 1/8" piece was salvaged from the old skylight and might be lexan. The thinner lower sheet of plastic has a small hole on the high side just inside the frame for air pressure changes. The plastic sheets extend to the edge of the wood frame and are fastened with 48 #8 SS screws. All sides of the wood frame, spacer, and screw holes in the spacer are coated with epoxy and the exposed sides have a layer of fiberglass cloth and mat with epoxy resin and are gel coated. The frame is secured to the roof with thickened epoxy. I used 1/8" thick black closed cell pipe insulation as gaskets for the plastic sheets. The pipe insulation has really sticky glue on one side and it is stuck to the frame and spacer. It can be disassembled if necessary by removing the screws. I found SS washers with neoprene for under the screw heads. I placed a small stepladder in the shower and stood in the roof opening to do most of the work. Much easier working standing up than bent over. The bottom part of the frame is fastened to the roof with epoxy and 4 SS screws into the aluminum roof framing around the opening. The screws are there mainly to locate the frame until the epoxy hardened, also to apply just enough pressure to squeeze out some of the thickened epoxy. I waxed the screws so they can be removed, but left them. Only way to remove the frame would be to saw it off. No more leaks. Time will tell if the pipe insulation holds up, but it didn't leak after spraying with a hose. I can post details on the steps I would take if doing this again, but it is about 2 pages long, in case someone else might do this. I think my new skylight looks a little better than the old one, but not particularly beautiful. It's not as high inside as the old one, 1 5/8" less. The top is not flat has the same curve as the roof. It could be made taller if desired. Seems to let in about the same amount or maybe a little more light than the old one. The old one looks better in the picture than it really is. After I finished, I hauled the old one back up on the roof for comparison.
Jerry, very nice job. I like the way you made it and joints super.
JohnH
For those who like the metal skylight, but would like for it to fit the curve of the roof and not have to do all the work of filling the old screw holes here is how that can be accomplished. Remove the skylight and clean off all the caulking on the skylight and coach. Wax the roof where the skylight sits. Tape a piece of plastic film on the coach over the opening just past the screw holes. Don't use duct tape, leaves a residue to clean off, shipping tape works well. Place some waxed nails as large as the screw in corner screw holes to locate the skylight. Cut off heads of nails, insert points up. Do a trial fit to see if it goes on easily. Mix up some epoxy with a filler and apply to bottom of skylight flange; thicker were the gap is greatest. Set it in place guided by the nails; two people needed for this. Some epoxy should squeeze out around the edges. Remove excess before it hardens. After the epoxy has cured for 3 hours (normal temperature of about 70) remove skylight, allow for full cure, caulk and reinstall. If you are leery about working with epoxy, Epoxy by the Leading Epoxy Manufacturer | WEST SYSTEM Epoxy (http://www.westsystem.com) has lots of info, guides, and videos about how to use it. I would suggest that anyone with an older coach like mine check for delaminations and if the screws are tight around the skylight and other items that are fastened to the roof. Tapping should not produce a hollow sound.
Thinking about the 3 hour cure, maybe just see if the nails come out, but replace until full cure so skylight doesn't blow or slide off roof.