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Author Topic: Delamination  (Read 284 times)


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« on: September 19, 2018, 06:43:02 PM »

1988 Royal Industries, Classic - 28' Class C motor home.
First time owner. A newbie to this crazy hobby
Under all windows I have delamination of the fiber glass siding from the substrate.
I removed the washroom window "smallest" to have a look see.
The only sealant around the outer flange of the window was the original stick on black foam tape.
Plus the window opening was cut too big and the window was not centered in the opening.
Leaving very little contact of the foam tape and contoured out skin, mostly at the top.
Water ingress from the top down.

Did or do manufactures put only the foam tape around openings to seal them up?
Or is there an extra layer of butyl putty that is put in.
This is what I will be putting in as I reseal all of the windows.

Is there any method to repair the delamination of the outer fiberglass and substrate?

Thanks to all


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Re: Delamination
« Reply #1 on: September 19, 2018, 06:48:06 PM »
Yes it can be repaired fairly easily if it is under the window. One of the sponsors of the site makes a delamination product

there are others as well.     
When repairing the window some people put in a piece of  rubber tape etc to cover the raw opening and prevent more water incursion
1990 Fleetwood Southwind on P30 chassis located in
Central NY in summer and beautiful Casa Grande AZ in winter

Gary RV_Wizard

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Re: Delamination
« Reply #2 on: September 20, 2018, 09:48:22 AM »
Butyl putty tape between the window frames and the sidewall is the norm, though some builders use squeeze tube sealant instead. I've not seen any sort of foam tape used in that application, but "foam" covers a bunch of different types. Some foams are waterproof but many are not.  The advantage of foam for the factory is that it doesn't squeeze out like butyl or liquid caulks, so no clean-up step afterwards.

It sounds like your window suffers mostly from sloppy construction quality, but if it lasted 30 years, maybe I'm being too harsh.
Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL


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Re: Delamination
« Reply #3 on: October 07, 2018, 09:31:03 AM »