Re: shoot thru hull transducer installations?
You will be okay with an in the hull mount if your running surface finish is not metalized or poly flake coated.
It needs to be installed on a flat space in the bilge as near to the transom as possible. Generally the instructions tell you how to test your installation surface by having a small amount of water in the bilge the comes up the sides of the puck. I ran water under the hull from a hose and the puck was able to sound off that in the driveway. It won't be anything near accurate but will let you check for the best position before you crack open the epoxy. Be sure to get all of the water out of the bilge and air dry overnight.
When I installed mine last year I took the extra step of sanding the mounting surface smooth with 400 and 800 grit sandpaper on an orbital sander to ensure best adhesion and surface to surface contact. Wipe the mounting area down with alcohol to remove any moisture, grease, and dirt.
Follow the epoxy directions to the letter and you'll be fine. Let the slow cure epoxy sit for the full 24 hours without disturbing it so no boating for day...
You'll most likely need to fish the wires thru the hull to the mounting location and if you don't have access to a fish tape these sink drain cleaners work perfectly as a cheep alternative. Good luck!!!
http://www.lowes.com/lowes/lkn?action=productDetail&productId=24641-319-LX-90220&detail=&lpage=none
