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[hugsta]

I would go with sikaflex rather than silicon, my personal preferance. Sikaflex is the same stuff they use to seal in the front windscreen of your car, although there are a couple of varieties now. It will therefore withstand temp changes, stop water penetration and is also quite flexable. You can get in white and a variety of other colours now.

Any bare bits of timber can be filled in with the sikaflex, just make sure they are dust free and clean. Use a damp cloth to get rid of excess, but be prepared as this stuff sticks to everything.