Hi Carl, I did my -10 windows with Silpruf. I did the Sportmans 2+2 window install method with mine. Windows have been in for 7 years now without any issue. Since Silpruf is silicon, make sure you protect any unpainted surfaces because it could cause fisheyes when you paint. There is nothing wrong with Sikaflex but when I did my research I did read that on boats they still recommend a UV tape be placed over the outside. But I doubt the windows in the plane will ever come close to UV exposure a boat is exposed too. I do believe Silpruf is easier to work with.