The problem with silicone is that despite it's advertising it doesn't last forever. Especially between parts that move a lot. When you need to recaulk, it's a mess to remove the old stuff. Which is why RVers generally use Dicor, butyl tape, etc. Something that is easier to remove when the time comes to redo it. Which is just about anything other than silicone.The silicone says all weather, does not yellow, so I would think that would help keep water from even reaching the fastener holes to begin with.