Eternabonding the windows.....

theoldwizard1 wrote:

Bert the Welder wrote:
Was in the shop today and the rubber/synthetic sticky tape they put around house windows these days got me thinking. Why not do that on RV's?
Wrap the window cutout with Eternabond tape, maybe the 2" stuff, inside the cutout frame and out over the outside. Just enough that it doesn't peek out from beneath the window frame. Then butyl on top to bed the window.

Why bother with the first step. Just butyl tape.

I do NOT believe that ANY caulk/sealant lasts "forever". When you place it between two dissimilar materials and expose it to a "non-sheltered" environment you have two powerful forces acting against it.

All materials heat and shrink with ambient temperature changes. The bigger the change in temperature the more expansion/contraction. This is a very powerful force working AGAINST your caulk/sealant !

Sunlight, especially the Ultraviolet portion of the spectrum, causes material to "breakdown" over time.

IMHO, design seals to accept butyl tape and be easily replaced.

EB isn't a caulk.
It won't be exposed to sun. It's under the frame/trim.
EB is designs to stick to a dissimilar material by design
EB is designed to flex with temp changes and movement
The EB is design for UV exposure, but refer to line #2
Butyl is still being used for it's original purpose of bedding the window and sealing around the screw holding said window in place. It's just bedding on the EB surface or at least the narrow strip that is wrapping around to the campers exterior surface.
Also, the butyl is still going to be a maintenance item. The EB isn't there to replace it, nor effect it's performance as a material. It's there to do what it's designed to do. A durable, tough, long lasting membrane to provide a primary seal to prevent water soaking/wicking into the exposed edge of the camper exterior shell and internal frame/insulation materials. The butyl still performs it's job of bedding the window into a water proof material, preventing water from getting into the camper, as long as it is still within it's functional life span.