Re: How do you install xducer on transom?
That material that Pointer used looks like UHMW plastic. It's used in a lot of industrial applications, but isn't real common out in the public. Check your local lumber yard or even a farm implement shop.
That's what I used for my xducer mount too...I scored a small scrap piece from work for my mounting board.
Another option to make a transducer mounting plate is to use a chunk of synthetic deck material (you know, the plastic stuff you can get at Menards, Lowes, etc to build a weather proof deck). A friend of mine used that and it works great too.
When you fasten the board to your hull, seal it up good with 5200 and screw it on. Or if your hull is virgin, you could even just epoxy the board to the hull without screws. Epoxy won't hold UHMW by itself very good though...even if you rough the back up good with sandpaper. Some ingredient in it is too "slick" to let the epoxy get a good hold on it.
I built my plate large enough to mount my transducer and left room for a speedometer sensor if I decide to add one in the future.