Covering Holes...

[Alphamacaroon]

Curious to hear about solutions people have used to cover up and waterproof various holes in places where aluminum meets frame on the Coupe.

Seems like no matter how well you align the aluminum there are just places that are really tough to completely close up (the top part of the passenger-side footbox firewall is one great example)

118761— (you can see I tried to fill it with silicone, but it's not really cutting it).

I've thought about using butyl rubber tape, but worried it won't hold up to the heat. I've used the metallic JB-weld putty to some success in a few small places.

I suppose the best solution is probably to fabricate and rivet some aluminum filler plates, but I'm just curious if others have come up with creative solutions? I hope it's not due to sub-par workmanship ;) — but that particular hole in the picture above seems impossible to fill with the aluminum FFR supplies you no matter how well you align everything (unless I got a faulty cut piece).

[edwardb]

Both Roadsters and Coupes (what I've had experience with) have some gaps that require filling. Sometimes they are big enough to require a piece of aluminum, like the tube out the front of the PS footbox on the Roadster. But most can be filled with other means. On my Coupe build, I know about the one you pictured. There are others, but agree that's one of the biggest. The majority are in the footbox areas. I've been using a product called Marine Tex. It's a filled 2-part epoxy, not too expensive, and thick enough that it stands up reasonably well and can be used to fill pretty large gaps. Comes in white or grey (very dark, almost black) and it's on Amazon. My process is to put a piece of heavy tape, like Gorilla tape, on one side. Then fill with the Marine Tex on the other, troweling it in as smooth as I can, and clean up excess with isopropyl alcohol. When it sets up, pull the tape. Since I use Lizard Skin, that gives another thick coat over the fill in the inside and makes it permanent in my experience. Tightly fitted and placed stick-on insulation (like Dynamat, etc.) would do something similar.

Another option, which I've seen some use and I used on my first build, is aluminum tape. Something with enough body that it can be bent and pushed into corners on the inside. I bought some at McMaster.

[David Williamson]

For the gaps that silicone can't fill I use aluminum tape. I also put it between the body and the bulb seal to help water proof the trunk area. Wait until you see the gaps in the rear wheel well area behind the seats. I used aluminum tape on my Mkll and it has held up well.
David W

[Alphamacaroon]

I keep hearing about aluminum tape, but the only aluminum tape I know of is the really thin stuff that is about the thickness of aluminum foil. I can't imagine that would hold up to much, so I assume you guys are talking about something else? I have purchased aluminum flashing (for roofing)— which is quite a bit thicker, but still easily bendable. Maybe that's closer to what you're talking about?

[David Williamson]

The aluminum tape is like heavy foil but it does stand up, no/limited gravel roads? my mkll has 40,000 miles on it and the back wheel wells are still water tight. On the coupe I am going to cover it with bed liner.
David W

[edwardb]

This is what I've used: https://www.mcmaster.com/7631a84. Found it to be just the right thickness and sticks well. Haven't run across anything exactly like it in retail, e.g. HD, Lowes, etc.

[Alphamacaroon]

Excellent, I'll give it a try. Thanks again all!