Re- epoxying transducer inside hull

[noclutch]

I found that my OEM Farina transducer had detached from the hull after experiencing erratic readings. The epoxy that it was glued down with is still completely adherant to the underside of transducer, just not the hull. It appears that the manufacturer had sprayed the inside of the hull with with a thin white gel coat layer that was too slick for the epoxy to stick to. The epoxy is black and about as hard as plastic.

Suggestions on what type of epoxy to use to re-attach the epoxied transducer to the hull? Of course I was going to de-grease then roughen the surfaces prior. FWIW the original transducer was placed fairly far forward in the hull but still came in contact with oily bilge water that sloshed foreward, which probably hastened it's detachment, thus an oil resistant epoxy I assume will be indicated.
Thanks!

 

[spoilsofwar]

Re: Re- epoxying transducer inside hull

1. Remove old epoxy from transducer
2. scuff up area where ducer was originally attached, and then clean thoroughly
3. construct some sort of "dam" around transducer to hold the epoxy in place while it cures (many ways to do this, I've seen good examples using tupperware containers or similar)
4. use a slow cure epoxy. The slower cure rate allows air bubbles to escape to the surface.

 

[noclutch]

Re: Re- epoxying transducer inside hull

Thanks spoilsofwar. Yes I'd thought of removing the epoxy from the transducer but afraid of damaging it in the process- the epoxy is so hard I'd practically have to cut and grind it away, and of course this is down in a ski locker (unless I want to fish the wires out and back).

 

[noclutch]

Re: Re- epoxying transducer inside hull

Would this or that be more appropriate for this application?

I went by three of boat stores today, and two of them suggested 5200. The last one discussed how epoxy is superior for transducer securing and suggested a putty as an alternative to two-part.
Thoughts?

 

[spoilsofwar]

Re: Re- epoxying transducer inside hull

I'd use West System 105 epoxy along with 206 slow-cure hardener.

WEST SYSTEM | Epoxy Hardeners - 206 Slow Hardener

 

[jserr68594]

Re: Re- epoxying transducer inside hull

I just had to deal with a faulty tranducer for my Faria gauge. I used GE silicone II. It was easy to work with and there are no issues!

 

[spoilsofwar]

Re: Re- epoxying transducer inside hull

I just had to deal with a faulty tranducer for my Faria gauge. I used GE silicone II. It was easy to work with and there are no issues!

This is possible, in fact Airmar even recommends this silicone (or at least they did at one point in time). I don't prefer silicone in any sort of adhesive application, but if you do the install properly it can work and provides the benefit of being easily removable later if need be. If you do something wrong, its going to come loose from hull again in a matter of time.

I used the slow-cure epoxy that humminbird recommends when installing my HDR 650 in the hull.

 

[noclutch]

Re: Re- epoxying transducer inside hull

Interesting. My understanding from one dealer was that the rubbery consistency of cured silicone was not as
"transparent" to the type of impulses a transducer sends out. Now my other sounder is a Garmin chartplotter, and it's transducer sits above a fluid bath( propylene glycol) in contact with the hull. Now that one was a pain to mount ( and I'm still waiting for it to spring a leak LOL)