westend - Why does everyone hate silicon for rv's/motorhomes? I mean, I know "all other silicon" products that are normal and not specified for rv's shouldn't be used, but this one is specially formulated for rv use. Just curious what the issues are and pitfalls or pros about silicon and RV's. Lastly though, i do plan to do what you said and use an approved sealant first to take care of holes/damages before covering over.
That roof coating contains silicone and is specified for EPDM roof coverings (among other surfaces). It's primary function is to protect the EPDM from UV degradation and to offer cooling because it's white.
Silicone is a great sealant when used in compression between two mating surfaces and not exposed to UV. Unfortunately, it also has drawbacks---the aforementioned UV degradation and, when cured, no other material will adhere to it, not even new silicone. You can test silicone's degrading by applying some to a surface and letting it sit outside. Within a couple of years it will start to lose it's bond and become worthless.
For your skylight and roof, I'd suggest to use materials that have been used by others with success--Butyl tape sealant, Dicor or other polymer sealants (no silicone), Eternabond tape, and screws with a flat washer or integral flange. If you have an EPDM roof with a white top layer, there is no need to coat it again but if you wish a shiny new white surface, I'd suggest to use an elastomeric roof coating.
Good luck with your repairs and have a great cruise!
