A sticky solution --- If you'll pardon the pun.

I have been looking back through some of the old "threads" and notice that there have been several mentions about sticking light lenses back on.
As many of you have discovered silicone is about as much use as a chocolate teapot. The answer to a maidens prayer I ALWAYS use is Polyurethane Sealant. It is available in White, Black, Grey, and Brown but sadly not available in Clear.
The one I use is manufactured by Wurth. Its is flexible but very strong, good anti-vibration characteristics and sticks like whatsit to a blanket.
I use it for all sorts of jobs on my Romahomes, around the house. I use it in bathrooms putting in baths and sinks and it will join or seal almost anything.
The only thing I have found it didnt like is the windscreen washer water bottle plastic.
Oh yes I havent tried the wifes mouth yet--- mainly cos it wont stay shut long enough for it to set !!!