There seems to be a very strong preference towards 4200 for underwater applications within the community. With that said, would you seal a depth finder with 4200 or the manufacturer supplied o-ring?
Depth finder installation
- Thread starter Project_Mayhem
- Start date
MIne shoots through the hull . No hole in boat. Its epoxied in place per manufactures recommendation
There are 4 parts to the transducer: The transducer itself which has a cable attached to it, a large nut that secures the transducer to the through hull, a through hull fitting (with a mushroom end) and a nut that secures the through hull to the boat. The last few transducers I installed used 4200 around the mushroom that goes outside the hull and 4200 on the lower threads where the nut holds the through hull to the hull. These are semi-permanent connections that need to be well sealed.
The nut holding the transducer itself in the through hull is not meant to be permanent or even semi-permanent, so do not use a sealant there, use the O-Ring suppled by the manufacturer. Depending on where you sail, paddle wheels get clogged with critters and crud and need to be cleaned, unscrew the nut, pull the transducer and insert the dummy plug. Clean the paddle wheel and put it back in. You might want to practice this once or twice before you launch. It can be a bit unnerving to pull out the transducer and watch water flow into the boat.
Modern transducer through hulls often have a little trap door inside. When the transducer is removed, the door is forced closed and the water flow is greatly reduced.
The instructions that came in the box of airmar transducer said to use 5200 and I used 5200 a few times on transducers and never had a leak of any kind and yes when I up graded my airmar I removed them even having used 5200 and used 5200 on my thruhulls when I replaced them no leaks.
Nick
Nick