I recently recaulked a couple of windows. The local RV dealer uses and recommends Nu-Flex 313 fast set silicone for things on the side. I used RV putty between the window and the coach sidewall. Then I sealed around the perimeter with the Nu-Flex. I would not recommend Dicor on the sides of the coach, at least not the self-leveling kind. I don't know if there is a different Dicor product that people use on the sides. Anyway, I found the Nu-Flex easy to work with, and the result looks very substantial and professional. YMMV