Will this make my boat sink?

Grunt_Sculpin · Aug 28, 2007

Hey everyone....got a dumb question....I installed a transducer on my new GPS Fishfinder the other day and I started thinking about it after the fact....Will the screws that are holding the transducer and cable attached to the boat take on small amounts of water? I put a marine grade caulking in the pre-drilled holes and then put the screws in and these are also short screws that only go in about an inch but I know that it is far enough to go past the gell coat and into the foam of the boat (It is a fiberglass boat). They are not far enough in to penetrate the inside of the boat though. Will this take on small amounts of water that might saturate the foam in some way causing damage over time?

Thanks in advance!

smithrock · Aug 28, 2007

Re: Will this make my boat sink?

put sealant over the screws as well

studlymandingo · Aug 28, 2007

Re: Will this make my boat sink?

The marine grade sealant is the proper stuff to keep it from leaking.

Duec66 · Aug 29, 2007

Re: Will this make my boat sink?

I had a nasty leak a week ago and traced it back to the screw holes for my transducer in the transom. I filled the holes with silicone and put the screws back and now there is no water at all in my bilge. So yes they can leak if you do not seal them corrctly, but it sounds like you did the right thing.

RubberFrog · Aug 29, 2007

Re: Will this make my boat sink?

Duec66- silicone is the worst thing you can use anywhere on a boat. Take the screws out, remove all of the silicone and replace it with 3m 4200.

Grunt_Sculpin · Aug 29, 2007

Re: Will this make my boat sink?

These screws do not go all the way through the boat so would the water still be able to end up in the boat? Do you think the foam inside the boat would stop the water from going any further?

Thanks!

PondTunes · Aug 29, 2007

Re: Will this make my boat sink?

You don't want waterlogged foam.. If the hull is breached and water is seeping in the foam will soak it up and never dry out, if left unchecked it will eventually cause the boat to sit lower in the water from all the extra water weight. Use the 3m stuff and seal it up.

rndn · Aug 29, 2007

Re: Will this make my boat sink?

Some people are unaware that marine grade sealants actually expand slightly when curing as regular sealants do not and may actually shrink slightly. Always use a good quality marine grade sealant by putting some in the holes, on the screw threads, and around the head of the screw.

Grunt_Sculpin · Aug 29, 2007

Re: Will this make my boat sink?

If I take the screws out and reapply the sealant will I have to use bigger screws? I had a hard enough time getting the screws in.

Thanks!

jtexas · Aug 29, 2007

Re: Will this make my boat sink?

no need for bigger screws in most cases.

The floatation foam used in boat manufacture is a closed cell foam, it takes prolonged exposure for it to become waterlogged (which it will do, eventually, probably).

Bigger problem is your transom is probably wood core, any exposure to water means trouble down the road - even if you seal it back up - best to treat the wood with something that will kill the rot. I've heard glycol is great for that.

mattttt25 · Sep 1, 2007

Re: Will this make my boat sink?

agree w/ others, use 4200 or 5200 seal when installing screws and a little more over the top of them.

next time, cut a small piece of starboard, 1/2" thick, and mount the transducer to that. then use 4200 or 5200 to mount the whole thing to your hull. no holes in your hull.

_brad_ · Sep 1, 2007

Re: Will this make my boat sink?

What about this stuff? I bought a whole thing and have used very little..

Kill two birds with one stone?

Nova II 260 · Sep 1, 2007

Re: Will this make my boat sink?

Use 3M 4200 on all screws. No need to over size the hole. When drilling a new hole, countersink the gel coat a little and it won't crack when installing the screws.
A good winter project is to remove all your hardware and coat the screws in with 4200 and reinstall.

cut a small piece of starboard, 1/2" thick, and mount the transducer to that. then use 4200 or 5200 to mount the whole thing to your hull. no holes in your hull.

Great idea Mattt! but I'd use 3M 5200

Will this make my boat sink?

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