Gary,
I'd be very cautious about epoxy/fiberglassing the stem/transducer in place.
If, for whatever reason it EVER 'goes South' you WILL have a BIG job {and
possibly HOLE} on your hands getting it out. Better to 'bed' it properly and
inspect it frequently.

On another point - WHENEVER you have a penetration of the hull - get a wood
PLUG that can be driven into the hole and/or fixture. {they come in sets, or
make your own out of Pine or Cedar - a relatively soft wood that WILL SWELL
when wet}. Wire or tie the proper size to the thru-hull and have a
short-handled, stout hammer aboard. If this is the only thru-hull, have it
tied there, as well.

If this sounds strange, check almost ANY book on off-shore sailing & SAFETY
ISSUES.

Regards,
Ron Magen
Backyard Boatshop

"Gary Warner" wrote in message
...

SNIP
I will - whether via glass or other method - make sure the transducer is
in there VERY solidly. I do know that I don't want it coming out and
leaving me with water pouring in.

Gary