Save a little antifreeze when winterizing and use it instead of water. It is safe for the plastic, works well, and won't freeze. If for some reason it drains, the transducer won't work which is gentle reminder to put fluid back in the housing. The first time that happened to me, it took a while to figure it out.
Don't quite follow if it is an in-hull transducer. Why the need for the 2" hole if an in-hull requires no hole through the hull ?
There is an adapter so the transducer can be mounted level on a non level part of the hull, such as the bow. Because of the angle there is a void between the hull and the transducer. Liquid is needed between the hull and transducer. I suppose you could fill it up with beeswax, but that's a lot of wax. If there is a flat spot for the transducer, then you are correct, any adhesive that does not have bubbles in will work.
Better living through wild ideas.
idea came from re placing the sensor in oil, antifreeze, or other mystical liquids which evaporate or fall over. I strongly believe all depth sensors (in or thru) since they were first sold could be mounted in-hull in a solid material such as silicone, toilet wax, etc, etc. and work perfectly. Eliminate another hole in the hull.From Airmar. The best place to locate the transducer is in forward of the keel and on or very near the centerline. This puts it in clear water and the sounding is less affected by heeling. Many boats do not have a horizontal surface on which to mount the transducer, this places the transducer on an angle as much as 22° (a common deadrise angle). When mounted at an angle the transducer is not measuring the depth of the water directly below the hull, it is measuring the distance to the bottom at a 22° angle. And as we all know the hypothenuse of a triangle is longer than any of its legs. This is problematic when the boat is not heeling, it is really bad when the boat is heeling such the transducer is pointing almost parallel to the water's surface.
Then a moment of silence for those poor unfortunate souls, because if they wanted to mount a through hull transducer aiming straight down, they've really got their work cut out for them. The only way to get around that problem is to start fabricating wedge shaped blocks out of ? ? ? and just praying these flimsy Rube Goldberg contraptions are going to stay firmly glued in position and not decide to move one day with the expected results :
Did the little green feller say how thick the putty was when the transducer was pressed into the putty ? In other words, could the putty be thick enough to allow the transducer to be installed straight down (vertically) when the hull was not horizontal ?
The Garmin In hull I installed came with 4 housings of different angles to get the transducer close to level. You could make your own angle out of PVC pipe I suppose. I stuck the housing in place with Bed-It Butyl tape and filled it with water. Works great.
It sounds like MHauser got his working. But in response to the Uncle Crazy, plumbers putty worked great. We found an area that was pure fiberglass and no core. Embedded the transducer in the putty and we immediately got results. It had a fish finder but the solid barrier made it find very few fish.
