Best Product To Glue and Seal a Large Hole on the Roof

[Racorman]

I've got a 30' Itasca with two 13,500 BTU air conditioners. One is dedicated to the rear bedroom. I’ve removed the rear A/C so I have room for a large group of solar panels.

The solar panels will go directly above the 14”x14” opening where the A/C was, and I have an 18”x18” piece of aluminum that I want to use to close up the opening on the fiberglass roof.

I’d like to find a product that would create a permanent seal as well as serving as a glue to bond the aluminum panel to the fiberglass roof. I don’t want to use any screws to anchor the aluminum panel.

Any suggestions for a good product to seal and bond.

Thanks

[Dale_Traveling]

I would say that isn't going to leak, ever.

[Racorman]

Project done..........

[Cloud_Dancer]

Well, what I would do is remove THOSE screws, countersink the holes in the aluminum plate, and use stainless ovalhead screws. The screwheads that I see in the photo have a sharp rim which is perfect for cutting holes in the Eternabond if you were to step on the Eternabond.
I would also take my small disc grinder and grind the sharp edge around the aluminum plate,...for same reason.

[westend]

Bruce Brown wrote:
Hey! What ever happened to "I don’t want to use any screws to anchor the aluminum panel". :B

Looks good, my only suggestion would be to also run some Eternabond around that panel too.

X2

Those are totally the wrong screwhead for using under the Eternabond

I wouldn't loose any sleep installing Eternabond tapes over the screws. The tapes, if properly installed, will be flexible enough to encapsulate the heads and the edge of the aluminum sheet.

One trick I picked up when using the Eternabond tapes is to use a small piece on top of a screw hole. install the screw through the tape and into the hole. The tape will wick up into the hole and around the head, making a really good seal. If you already have Lexel in the holes, it would be superfluous.

Head up: any surface you apply Eternabond onto needs to be "hospital clean" (use solvent). Also, no trace of silicone present.

[Cloud_Dancer]

Those are totally the wrong screwhead for using under the Eternabond.

[SacsTC]

Bruce Brown wrote:
Hey! What ever happened to "I don’t want to use any screws to anchor the aluminum panel". :B

Looks good, my only suggestion would be to also run some Eternabond around that panel too.

Agreed, also cover the screw heads. That's a leak waiting to happen if they are left not sealed.

[mtrumpet]

Bruce Brown wrote:
Hey! What ever happened to "I don’t want to use any screws to anchor the aluminum panel". :B

Looks good, my only suggestion would be to also run some Eternabond around that panel too.

X2. I too recommend Eternabond around the edges (and over the screws) of the plate just to "play it safe" with regard to any possible avenues for leaks.

[Bruce_Brown]

Hey! What ever happened to "I don’t want to use any screws to anchor the aluminum panel". :B

Looks good, my only suggestion would be to also run some Eternabond around that panel too.

[Racorman]

Project almost completed. I used LEXEL as my bonding material and then screwed in the aluminum panel to the fiberglass roof. Filled the hole with an an insulator for RV Roof Vents w/Removable Fleece Cover from our old Lance Camper days. I covered the interior opening with a Coleman Air Intake Grill (part# 6798-3041)

Easy....... peezy

[10forty2]

If it's a fiberglass roof, can't you lay something down to fill the hole and fiberglass over it to seal everything nicely to the roof? I think that'd be my preference.

[Bumpyroad]

permanent = 3M 5200 IIRC. but I think I would just install a standard vent cover and raise the panels some.

bumpy

[Dale_Traveling]

My first thought is you really need to screw it down but not to the existing roof. I would cut wood spacers to fit the gap between the exterior roof and interior ceiling and side to side. Make them a 1/16 or an 1/8 undersized up and down which will help pull every thing tight later. Screw the aluminum you have to the spaces and trim out a piece of 3/8 or so ply and screw that to the spaces from the bottom. This is where undersizing will pull the two covers tight. Use Proflex Sealant under the aluminum and any exposed hardware on the roof. Seal the edges of the aluminum plate Eternabond. Also paint the aluminum before installing.

To make the interior cover look a bit better you can add edge wood to hide the ply layers. Give it a coat of paint to match the interior ceiling color. You could also fill the space between the upper and lower covers with spray foam or fiberglass which will help with heating and cooling plus deaden sound.

[RLS7201]

If you mounted the panels about 3" above the opening, you could use a vent to fill the hole.

Richard

[donn0128]

Outside? Dicor and eternabond tape around the edges. What are you going to do about the ugly hole inside?