Sealing around speaker: Butyl tape or caulk?

[RhythmDoctor]

I have a little topside leak that I want to plug. I've traced the leak to a poor exterior speaker installation by a prior owner. It's a Sony marine speaker that is glued in place by 5200 (I think) onto a coaming that is directly exposed to rainwater. On the starboard side it's water tight. On the port side, though, it leaks every time it rains. I went below and can see that there is sunlight passing through one part of the hole in the fiberglass at the bottom of the speaker. It appears that he did not use enough caulk to get a complete seal. So rainwater comes right through the grill and then seeps between the fiberglass and the speaker.

Because 5200 is so tough, I do not want to remove the speaker. It will almost certainly destroy the grill, the speaker, and possibly the fiberglass too. I want to reach back behind the speaker and slap some sealant into the void. If that does not work, then I'll have to risk removing it.

I basically have two choices - either squirt some 3M Marine Silicone in there, or take some butyl tape and roll it into a tubular shape and mash it into the void space.

Which would you guys suggest?

[pdqaltair]

Caulk.

Butyl is good stuff, but really only works if you can get clean surfaces and then bolt them together as though it were a gasket.

[baboon]

I agree butyl tape is most likely not going to work. Silicone might, but it's reputation for contaminating the surface so nothing else ever works again has been well discussd on this site. I have tried to fix leaks with stop gap measures on my boat in the past and it never worked.

Compared to other boat stuff a speaker is cheep. If it is 5200 it might be best to destroy the speaker in such a way that the outer ring and bulkead is intact. You could then grind down the 5200 to the original surface and put in a new speaker using a proper sealent or butyl. I that fails then it might be easy to just cut the whole thing out and put in a bigger speaker. This may sound exteme, but my limited experience with 5200 has convinced me to not even have a tube of it near the boat.

[deniseO30]

Rick use 4200
http://multimedia.3m.com/mws/mediawe...400-5507-1.pdf

[RhythmDoctor]

Originally Posted by baboon

I agree butyl tape is most likely not going to work. Silicone might, but it's reputation for contaminating the surface so nothing else ever works again has been well discussd on this site. I have tried to fix leaks with stop gap measures on my boat in the past and it never worked.

Compared to other boat stuff a speaker is cheep. If it is 5200 it might be best to destroy the speaker in such a way that the outer ring and bulkead is intact. You could then grind down the 5200 to the original surface and put in a new speaker using a proper sealent or butyl. I that fails then it might be easy to just cut the whole thing out and put in a bigger speaker. This may sound exteme, but my limited experience with 5200 has convinced me to not even have a tube of it near the boat.

Sorry, there are details that are just too time consuming to type out. Your suggestion will not work for me. It appears that the previous owner already enlarged a prior speaker, to the point where these speakers are as large as the available flat space. Going bigger is therefore not an option, and the risk of damaging the fiberglass by taking out the current speakers is too great. I will have to try a "stopgap" measure and hope it works.

I've got some leftover 4200 in the fridge, so if it is still good I will try that.

[baboon]

Good luck, sorry things are too difficult to get at it another way. I have used dental syringes (the type they give you to rinse a socket once a tooth is pulled) to get thick stuff into tight spots. I have even been able to use them with thickened epoxy, so inecting 4200 with one might work. I have also tried using a standard syringe with a big metal needle (14 g) but that did not work out too well.