Which Sealant for Fan Replacement

[motts461]

I am replacing a roof vent with a MaxxAir Deluxe Fan on my Minnie Winnie 31G.
I know Winnebago uses silicone based sealants, NuFlex 311, at the factory. My question is should I stay with silicone or try and clean all the silicone off of the fiberglass roof and switch to Dicor? I think Winnebago uses straight silicone under the fan base then Nuflex 311 on top. If I switch to Dicor I would use Butyl tape under the base and Dicor on top.

 

[ThomB]

Why not bypass the Dicor and go Eternabond? Straight edged pieces seem to be what it’s made for. I am contemplating going onto the roof and replace all the Dicor (on the straight edged pieces) with the tape. I’ve used it to seal up a couple holes left by a satellite dish removal and after about 15K miles (and 2 years) it looks almost like the day I put it down.