epoxing inhull transducer help

[ranchos]

need some tips for epoxing inhull transducer, i purchased slow cure epoxy, i've sanded down area of choice, but how do you keep epoxy from flowing all over, how far off the hull should the transducer be off the hull and how do you hold it upright, or any other tips?

 

[roscoe]

Re: epoxing inhull transducer help

I think the easiest way to keep the epoxy from running all over is to take a foot or so of rope caulk.
Make a circle out of it and place it on the hull to create a dam that will keep the epoxy contained.

The epoxy only has to be thick enough to cover all surface irregularities.

This info from lowrance dot com sonar FAQ page.

Shoot-Thru Hull Transducers
Your unit may read erratic depth with a Shoot-Thru Hull Transducer if the transducer is not intact with the boat or if you are using the wrong kind of epoxy. The main reason for poor depth can be traced back to the way the transducer is installed.

Ideal spot is 2 inches up from the drain hole and 2 inches off set from the keel of the boat.
Make sure the transducer is on the pad of the boat. Having the transducer too far forward will decrease the performance at high speed.
Make sure the transducer is clear from the bilge pump board, typically found near the pad area of the boat.

This installation must be made in an area of the hull that is made from solid fiberglass, with no air bubbles or separated layers. If the hull is of multi-layer or "sandwich" construction, you will have to remove the inner layer of fiberglass and the wood or foam core to expose the outer layer of the hull.

Sand the hull down with 80 or 100 grit sandpaper. Make sure that you sand all the way to the fiberglass. Most boats have a gel coat lining that is sprayed in the hull.

Use a 2-part hard setting epoxy, Non-Metallic, Non-Porous, preferably ours or True-Bond from True Value hardware stores. Make sure when mixing the epoxy you don’t whip it, this will only create more air bubbles.
Apply the epoxy to the fiberglass and to the face of the transducer, then lay the transducer in at an angle and slowly bring it down till it is flat. This will squeeze any air out between the transducer and the hull of the boat. Move the transducer in a circular motion while applying pressure; this will work any air bubbles out.
Set something heavy (5 or 10 pounds) on the top of the transducer and allow 24 hours to cure.