transducer mount

I had a hard time trying to goop the pool noodle...I think it's just me but I tried another method.
1.  bought a tupperware from walmart approx 4.5 inches in diameter.  cut out the bottom leaving enough lip for the goop to attach to hull and tupperware
2.  cut out a pool noodle to fit inside tupperware to the brim and cut out the inside for transducer
3.  placed a hole on cap of tupperware for wire to go through and screw tight after adding water
4.  gooped a velcro to hull to secure my battery pack
Works like a charm

That's an interesting variation, almost seems retro to the time a few years ago when we were trying gooping pvc sections, filling with water & inserting t/d,  and capping.  But this looks simpler and looks like it will work.   I wonder why you had trouble gooping the foam, but not the tupperware or the velcro. I suppose you used brand-name marine or plumber's GOOP?
I lightly sanded and wiped the area of the hull with denatured alcohol, and my foam donut has been on there for months now.

must have had the wrong noodle somehow...goop worked well but just had too many leaks from around the noodle. got it from target....used the left over to put inside hull as extra bouyant.     the way I have it works really well.  enough water to cover transducer if spillage occur.