i don't want to make this post too large ...
just want to point to new or young people just entering the world of yachts and larger boats , that famous and omnipresent 3M 5200 is NOT for all the applications and DIY chores in your boat.
Some people assume 5200 is for ANY application that need a sealant.
Actually, with years, i found that 5200 is one of the LESS useful products you need in a boat, specially for DIY's ....
Don't missunderstand me ... 5200 is great !!! great adhesion , good sealant, very powerful bonding, but no needed for most of the chores ..
Also, silicon is NOT a very adequated product either ... this is nice perhaps for a tub in your house, but also, silicon left a horrible residue, is not compatible with many materials, get aged fast , mildew, is nOT sun resistant , etc etc etc ... Silicon and 5200 are in the very extremes of the line ... 5200 bond is almost indestructible in many cases, this is highly UNDESIRABLE , specially if you have to replace or change the part.
I humbly recommend the use of 3M 4000, that is metal to plastic bond capable (unlike the 5200 !!!) , is more flexible, dont age too much, is VERY flexible and has some adherence properties.
Think of 3M 4000 as a 5200 less extreme, more material-compatible, less powerful, more flexible, and very practical. 3M 4000 is perfect substitute to Silicon and is great for most of your DIY's jobs .... can be used over and under water too ... great for hatches and most of the jobs. Great for gasketing. Stay flexible for decades.
5200 is NEITHER good for windshields !!!! Neither for metals !!!
basically 5200 is great in a manufacturing process for permanent attachments, but most of DIY need something more flexible and rational as 3M 4000 or equiv. (i am not related to 3M or sell 3M at all )
excuse my so horrible english ...