Warning On Old Depth Transducers!

[Kiltmadoc]

Hopefully, everyone can learn from our experience.
Here's the situation: 1981 C&C 32 with DMI corinthian electronics from the early 1990's (the AWI has a copyright date of 1992). Our depth finder was acting odd during the summer and we decided to service it while in winter storage. Given what we found, it's amazing it worked at all. FWIW, I dont blame DMI at all, they have good gear, but ALL gear wears out eventually. They have also been extremely helpful at getting us replacement parts.

What scared me is that it took almost no effort to push the core through it's nylon thru-hull fitting. The corrosion and compromised engineering could have led to quite the leak forming under our floorboards.

I strongly recommend that anyone with a 10+ year old transducer or nylon thru-hull check their seal and make sure all your thru-hulls are easily accessible. Our solution, going forward, is to seal the current 2-inch hole under the floor and put a new hole somewhere else where it's reachable.

Here's an album of what happened and what we found (view slideshow for detailed descriptions):


Datamarine Transducer pictures by jwqm - Photobucket

[Sabreman]

I have this very unit and will check it out the next time that I'm at the boat. We've had the oat for 5 years and I've never even pulled the transducer (I routinely pull the knotmeter transducer).

Very scary. Thank you for the community service bulletin. SailNet at it's best!

[Faster]

Good post, Kilt! I'm sure many of us need to follow up on this!

[Kiltmadoc]

I just found a posting on gluing a thru-hull transducer to a hull and achieving good depth accuracy. Anyone else done this to prevent another hole being poked in one's boat?
weblink:
Depth Sounder In-hull Transducer Mounting

[Faster]

I believe you'll lose some range - an alternate in-hull method is to create a liquid filled cavity and mount the transducer in that.

The loss of range may not be an issue, depending on the initial range of the sounder and your sailing area and practices.

[jrd22]

We have used silicone to install a transducer in a couple of different boats and it has worked fairly well. Like Faster said I think there is some loss of maximum range but they have worked well in general. Finding the best location is important, if there are any small voids in the fiberglass layup it causes problems. You also have to squeeze out the silicone so that you don't get any bubbles in it. We currently have two depth transducers in wells that work great. The wells are filled with RV antifreeze, you can also use mineral oil.

[HUGOSALT]

I have been using silicone to mount my sounder in my hull for 20 years...when it was recommended to make a box and suspend sounder in oil (oil I think).
Am extremely happy over the years...one must make sure there are no voids in the hull, and the angle allows
for a correct depth reading.
Don't make another hole in your hull, not necessary!
However I do have the original sounder in a not so easy to reach location that I will check/remove. thanks for the heads up. Hugo

[P35juniper]

I've got mine stuck to the hull to the hull with toliet ring wax, so far so good,

[arf145]

Originally Posted by P35juniper

I've got mine stuck to the hull to the hull with toliet ring wax, so far so good,

Had mine mounted this way for the last 3 seasons with excellent results. If we're losing any signal strength, I'm not aware of it--Of course I'm usually most interested in the depth when it's 10 feet and under.

[scottyt]

i have my transducers mounted with gelcoat ( waxed the ducer first ). i have istalled others with 4200. just use a zip lock bag of water to find a spot on the boat that it works at.

also this wont work on a cored hull, solid glass only.