What sealant for underwater fittings?

[EugeneR]

I bent my trim tab mounting plates while removing them in order to get some clean anti-foul lines around them.

So, I'm replacing them. To do this, I need to reseal the screws / holes to prevent water from getting into the transom. Also, the old plates seems to have been "stuck on" using sealant and it seems sensible to do so again.

I remember that there were several types of sealant which could be used under water but to avoid costly assumptions, I thought I'd check here to find out what works best under water.

What is the recommend sealant for such underwater seals?

Is it sensible to seal behind the entire mounting plate (30cm x 10cm) in such a case?

Many thanks

Eugene

 

[tobble]

Sikaflex 291

Spread all over the plate - evenly. squirt it on with the mastic gun then spread it out with a scraper or whatever, such as to avoid air pockets. assemble it, but don't crank the nuts/bolts right up for 24 hrs, so you don't squeeze out all the sealant... but being trim tabs that take a lot of force you don't want a massive thick layer either.

Don't forget to degrease with tissue and solvent (meths works for me) before you start

Be warned you won't get it off again without a fight.

 

[KAL]

Try CT-1. It stays flexible and also acts as an adhesive. You can even put it on underwater if you need to.