Depth Sounder Oil Leaking Out

[seandepagnier]

Every time I careen my boat (boat at 50 degrees for 7 hours), all the oil in the depth sounder leaks out and I have to replace it. Is this normal? This makes me think it also leaks out whenever heeled more than 40 degrees (ie: knockdown)

Why do they design depth sounders like this? Should I just stick sealant in or is there a better option? Should I use grease or something that won't leak?

[Wotname]

Try sealing the hole where the oil is leaking out.
Presumably your transducer does not pentrate the hull so the oil allows the transducer to "shoot" its signal from it's face through the solid hull.

Another common option is to use a through hull transducer so it's "face" is already outside the hull and thus in direct contact with the water.

[seandepagnier]

I prefer not to have a thru hole. So it's recommended to just use sealant? The cup is already sealed to the hull, it's just the top of the cup that the transducer sits in just twists to lock but isn't sealed.

[Kokanee]

A light grease will work fine as long as there are no air bubbles between the transducer face and the hull.

[rwidman]

Originally Posted by boat_alexandra

I prefer not to have a thru hole. So it's recommended to just use sealant? The cup is already sealed to the hull, it's just the top of the cup that the transducer sits in just twists to lock but isn't sealed.

If it's an Airmar P79 it's supposed to have a rubber O ring that seals it. Replace the O ring. If it's something else (you didn't specify), you are on your own. Find a non-permanent way to seal it.

[hamburking]

LOL...I have the same problem. The transducer sits in a little tub of oil. On my boat, there is a lid with a ring of bolt holes, and no bolts. Just good old gravity holding it together. I guess I should get around to bolting that lid down. I think a little sealant would do the trick you desire...but it will be tricky to get the sealant to hold to a greasy surface...you've got some cleaning to do first.

[sanibel sailor]

I have thought of getting some medical ultrasound gel for mine. It is KY consistency and won't leak, cleanup is easy and it is designed for the purpose. EBay is cheap, I just have water in mine (see no point in oil) but I think I will replace mine with gel if I ever have to open it up.

[rwidman]

Antifreeze is a better choice than oil. They used to recommend mineral oil but they changed that because the oil dissolve some sealants over time and leaks (where the cup was attached to the hull) developed. Water is fine if you never take your boat to freezing climates.

You need a fluid to conduct the sound from the transducer to the hull and back. Unless you filled the entire cup with gel and had no air bubbles, it would likely not work or become intermittent. Better to stick with the plan than try to re-engineer something.

[sanibel sailor]

Better to stick with the plan than try to re-engineer something.

"the plan" originally was to cut a hole in the hull... it has been re-engineered, some people call it an improvement.

[rwidman]

Originally Posted by sanibel sailor

Better to stick with the plan than try to re-engineer something.

"the plan" originally was to cut a hole in the hull... it has been re-engineered, some people call it an improvement.

Dumb. Read my post again. Put some thought into it.

[phipseml]

We used to just glue the transducer onto the hull with a blob of silicone. Lasted two years until we sold the boat. It worked very well, except that we had to be careful when packing the locker to not knock it over. It seems that anything will work that has no air bubbles, so exchanging the oil with something sticky might be a good solution.

[rwidman]

The advantage to the Airmar design is that you can mount it to an angled hull but still have it pointing straight down for an accurate reading..

The oil (or antifreeze) will not leak out if the rubber O ring is properly in place.