Installed a lowrance 4x on my jon boat today. Took it out on the water and when I loaded the boat there was a bunch of water in the plug area. Normally it's bone dry so I would conclude it's from the holes I drilled for the transducer. I covered the screws in marine grade epoxy prior to installation but it's pretty clear I didn't get a good seal. Anyone have any tips on how to seal this better? Thanks in advance.

3M 5200

3M 5200

Would it be a bad idea to put it around the head of the screw?

It's permanent. Once it dries it's not coming off without a fight.

Silicone, get some waterproof silicone caulking. There is marine grade. Make sure everything is dry and you can put it all around and cover the head. When it cures it is waterproof and water tight. No water can get it. It isn't to hard to peel off if you need to unscrew. I usually drill the pilot hole, put a dap of silicone in it and screw the transducer tight then cover the screw area. Then its watertight.

Put whatever sealant you use on the screw threads and in the hole before you screw them in. It will ooze out around the screw and seal out the water. Putting it on the head of the screw then won't be necessary.

When you use silicone. Put some around the screws. Let it cure a little bit before the final torquing. This will give it time to make a gasket. If you tighten it down before it is somewaht cured it will only squeeze it all out from under the screw head leaving nothing behind to act as a gasket.

 

I have also wrapped the screw threads with teflon tape before installing.

Take it back off and put silicone in and around the holes before you put the screws in. You should be good to go after that. 

When you use silicone. Put some around the screws. Let it cure a little bit before the final torquing. This will give it time to make a gasket. If you tighten it down before it is somewaht cured it will only squeeze it all out from under the screw head leaving nothing behind to act as a gasket.

 

I have also wrapped the screw threads with teflon tape before installing.

How long do you let it cure before you screw it in?

Will this work? I know it's not marine.

How long do you let it cure before you screw it in?

 

I usually let it sit for a few hours.

You can also just fill the hole with silicone.  Let it sit overnight, then reinstall the screws.

 

The screw will drive into the silicone, which is set, compressing it between the hull and the screw, making a watertight seal.

3M 5200

This not Dap

This not Dap

Won't the dap work?

I couldn't find 3M 5200.

3M 5200 is a marine sealant ideal for your application.take out whatever you used, clean the surface, apply the 5200 and install the hardware, let dry and you are good to go.

Tom

Won't the dap work?

I couldn't find 3M 5200.

DAP - Latex - fine for bathroom sink

3M 5200 - Polyurethane - marine grade