Hull mounted transducer melting through?!

I check AquaHunters every now and then.  Found the following this morning.   I am not an alarmist, but thought this worth passing on.  Someone removed an inside the hull mounted, glued on transducer, and found a small melted spot on the hull.  Reply #23.

http://forum.aquahunters.com/index.php?topic=820.15

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was it the transducer or the adhesive?

was it the transducer or the adhesive?

my guess is it was a reaction between the adhesive and the hull material...

that's pretty much what I was getting at.

The upside is his temp reading is probably accurate now 

What the heck did he use to affix the transducer; super glue or some 2-part epoxy/resin? There isn't enough acetone in lexel or marine goop to do that kind of damage.  The curing process of these doesn't heat up that much either.

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Oops, sorry.  Here is the post.  No followup from the folks who were going to check their hulls.  I posted a question about the adhesive he originally used.

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Rocket
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March 18, 2010, 01:38:37 PM
Re: Transducer mounting?

Holy Sh!t, I am in the process of revamping my Tarpon 160 and I removed the transducer that was on gooped to the inside of the hull. You would not believe what I saw. Most of us will never remove the transducer so there would be no way to see the little metal ball on the bottom of the transducer heating up and slowly melting a hole in the hull!

I dont know if it would make it all the way through but kinda scary to think you could be melting a hole in your yak.
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You know, thinking about it, I am gonna guess that either the transducer was defective, OR, the glue insulates it and creates the problem.

Since my transducer typically reads close to the actual water temperature (in the 40s lately), I don't think it's possible for something that small to be hot enough to melt in one place, and get an accurate temperature reading in another.  Guess whatever glue he used could have reacted to the hull and/or transducer, OR he had a defective unit, or (least likely) the glue insulated it enough to allow heat to build to dangerous levels.  BUT, thinking about it like that, the same glue should have insulated the hull.

Defective unit, or some crazy, over-reactive glue was used.

Unless this guy paddles in boiling water or really f'd up the transducer wiring and power source that isn't the cause.  That metal "nub" is the temperature probe and shouldn't be heating up more than ambient.  Does he have something forcing the transducer in place so that the hole is actually from underside the hull?

Hopefully he isn't expecting OK to send him his free weld rod... I've been waiting for over a year now for mine.  I will not be buying another OK Kayak.

  Ultrasound will cause metal to heat up if it's exposed to the ultrasonic waves.  Maybe the transducer was bad?  Having the TC exposed to the transducers output somehow internally maybe caused it to heat up?

I think they were a couple weeks early with their April Fool's Joke over at AquaHunters.  This just seems silly and I'd like to see pictures before I even consider believing it.

My bet is that he had the unit plugged into a 12 volt+ power supply, has a short in the cable, AND left it on out of the water in the garage or some thing. The head unit, not getting a good reading, kept sending PEAK pulses thru the transducer for hours. That would get it hot. With nothing to cool the plastic hull, it melted? Still hard to believe it got that hot. I went out in the garage and flicked on my Lowrance in the boat, and though I could hear it clicking and feel it when I touched the bottom of the transducer, it wasn't even warm after an hour. Something to send to Lowrance techs for the "what if" guys.

You might have hit upon it, Troutnut.

Now, I have a question, kinda related,and hopefully not a thread hijack.  Is it dangerous to have your sonar unit on when the transducer is out of the water? I try to avoid this, but I accidentally hit the button the other day and then quickly turned it off. Then I noticed that the transducer was laying on its side and pointing right at my "family jewels."   It was only about 4 feet away!
I guess that's better than finding it pointed at my head.

I read in the manual that came with it never to turn the unit on when the transducer is out of the water.  In our case, this would mean not to turn the unit on when the yak is out of the water, if you have a permanently installed transducer.

Mine is not permanently installed, since I have a portable sonar (Humminbird Piranha 4) that I move from boat to boat. I checked the hull inside of all my "donuts," and there is no sign of any heating damage from the transducer. Just wondering....

Sound won't hurt your jewels! 

Whew! Thanks for setting my ...er...mind... at ease, Nick.