inside hull fishfinder mounting

[iam2sam]

I have a new Lawrance fishfinder to mount in my Seanymph. I would prefer to mount inside the hull. I have read of several examples that use a small "moat" and water or some other fluid to couple the transducer to the water. Does anyone have pics of an actual working setup that they could share? Thanks.

 

[derekdiruz]

Interested

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[Al U Minium]

Just drill a hole in the bottom and stick the threaded stem through from underneath. Chase the nut down tight inside the hull and you are done. Don't paint the face of the transducer.

 

[perchjerker]

your mounting instructions for your transducer will tell you that you cannot mount a shoot thru hull t/d in a boat with an aluminum hull

I know, I just installed one and saw it in the manual

 

[iam2sam]

your mounting instructions for your transducer will tell you that you cannot mount a shoot thru hull t/d in a boat with an aluminum hull

I know, I just installed one and saw it in the manual

Yep, I'm certain the manual does say that. I'm also certain that I have seen posts from numerous parties (possibly not on this board) who claim that they have done this with unqualified success. The consensus seems to be that there needs to be an uninterrupted conductor for the sonic/ultrasonic radiation between the transducer and the reflecting object or surface, and that water-Al-water with no air gap consitutes such a conductor. I have a strong preference for avoiding through hull holes below the water line, sealed or not. I would have tried this with my aluminum canoe, except for the fact that the Garmin FF I had for that boat had a temp sensor (the Lawrence does not) and that obviously wasn't going to work.

 

[perchjerker]

one possible way it could be done would be to glue it to the hull with acoustic epoxy designed for this purpose. I think there is also a acoustic silicone sealant that may be better and easier to remove if needed.

But if you did not get satisfactory performance then you would have to either remove it get another t/d as once its epoxied into place it will be almost impossible to (the epoxy) remove without damaging it.

making a "moat" out of water would be highly questionable to me, how are you going to insure that the water and t/d will stay in place while the boat is underway and no air bubbles will get into the water.

It sounds fine on paper but I doubt it would work

there may be other ways to do it but I prefer to stick with the manufacturers recommendations