Fixing transducer to inside of hull

[quailrunner]

Finalizing install of a new Huminbird 650 depth gauge by "gluing" to inside of hull just forward and starboard of engine. What's the preferred approach for this? I've seen silicone, WestMarine 105/205, and other options recommended. What about the MarineTex putty stuff? I gather that keeping air bubbles out is the most important thing (I've already tested it to find a good spot). I think this was discussed recently; if so, please point me at the thread?

 

[Sharritan]

Easy to do and works fine. I used marine silocone and it works great. I'm sure several folks will chime in and say silicone isnt the way to go, but I have never had any problems at all. Plus, mounting it this way doesnt paint you in a corner if you decide you want to move it later.

 

[northern]

I have upper and lower helms. The upper has a through hull transducer. 4 years ago I put a fish finder (Eagle 320) on lower helm. I put the transducer on the inside. Used cylicon form local hardware store. 3 tubes for $9.99. Cleaned hull with Spray Nine, put 1/2" of cylicone on hull, pushed transducer into it, coverd transducer with cylicon an inch plus on all sides including the top. Let sit for week before turning on as clyicon took long time to firm up. The one in cylicon works better than the through hull one. No problem even gives me temperature. No mold in cylicon yet. Not sure if I needed to cover the whole transducer in cylicon but it protects it when I step on it by accident.

 

[quailrunner]

Thanks! It works well enough just sitting in the bilge, so I won't do the job until I pull it for the season.

 

[mperlst216]

Using silicone will be a total waste of your time and make the transducer useless. Humminbird says never ever use silicone. I called them directly and got that answer after a local repair guy used silicone and all I got was a 1 ft reading everywhere. Both Humminbird and Lowrance make a 2 part epoxy that is specifically designed to mount a transducer into the bilge. Why use anything else? I put mine in the flattest spot I could find.