Sealant For Exterior Fasteners and Penetrations.
HERR42.
Not sure who you are/were asking the question of, but...here's a thought.
I have found through a good deal of first hand experience with my 20 year old camper that a GOOD quality exterior "Latex" sealant, in the typical tube, will work just fine! A lot of folks will go with...100% Silicone.
The reason I prefer/suggest Latex is that it cleans up completely with water, and leaves no smeary look or dust collecting residue like Silicone.
I've used it on everything including roof vents, window frames, screws, the lot. Then washed every down with water, and you can't even tell the sealant is there. And NEVER had a ...leak of any kind. The key is getting the Latex sealant "inside/between" the joint, or in the screw hole, whatever. Not globbing it around the outside.The stuff oozing out isn't what's doing the sealing.
IF you are going to just "bead" around the outside of a joint or glob it around the top of a screw head, then Silicone would be a better choice. It will adhere better.
Trust it will work for you.
Coop.