Silicone caulk has no place on a boat other than bedding certain types of ports and covering the ends of cotter pins. 5200 has almost as few uses on a boat IMHO. It has far too tenacious a grip and is a pain to unbond if you ever have to remove the hardware in question.
Sealing leaks from beneath is a really, really bad idea, since that can trap water inside the hole and lead to serious problems like the core penetration and delamination. Generally, deck fittings on a sailboat should only be sealed from the outside, so that any leaks are fairly apparent and visible on the inside.
3M 4200 is good, SikaFlex 291 is good, butyl tape is good, but it depends on what you're sealing.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.
—Cpt. Mal Reynolds, Serenity (edited)
If you're new to the Sailnet Forums... please read this To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Still—DON'T READ THAT POST AGAIN.