Depth sounder issue?

[steve yates]

Mytransducer wasnt working, I epoxied in the tube to the hull, added some olive oil and pit the transducer in. Initially it was giving me fluctiating readings, playing around I realised it did that if I pushed it all the way down till it was hard against the hull, whereas if I held it up a bit, it gave me correct readings.. So I set it so it floated in the oil a bit above the hull surface, and everything was working fine. I left it running all afternoon and by evening noticed the numbers had vanished, then they reappeared, then vanished, then reappeared and vanished again. They reappear with a consistent depth but having them vanish would be very disconcerting in use.
Any ideas what I should be looking for?

 

[Baddox]

I’d check for loose connections or see if the oil has gone cloudy if it’s cold enough.

 

[steve yates]

It did get cold, and good point, olive oil separates in the old from memory!

 

[Stemar]

It did get cold, and good point, olive oil separates in the old from memory!

Is that why a number of suppliers recommend castor oil?

 

[steve yates]

Probably, but i have heard any oil will do, and it was in the cupboard handy for testing

 

[Rum Run]

this appearing and disappearing, is it the while display going blank or are the numbers being replaced with dashes? If the former I could be the power cable having intermittent breaks of contact, or the internal linear regulator having a fit, in which case NASA can fix it.
Interesting point about the oil clouding up, but I can't see it being the problem

 

[peter gibbs]

Mytransducer wasnt working, I epoxied in the tube to the hull, added some olive oil and pit the transducer in. Initially it was giving me fluctiating readings, playing around I realised it did that if I pushed it all the way down till it was hard against the hull, whereas if I held it up a bit, it gave me correct readings.. So I set it so it floated in the oil a bit above the hull surface, and everything was working fine. I left it running all afternoon and by evening noticed the numbers had vanished, then they reappeared, then vanished, then reappeared and vanished again. They reappear with a consistent depth but having them vanish would be very disconcerting in use.
Any ideas what I should be looking for?

The liquid must be free of all bubbles to avoid intermittent performance. Turbulence over the hull opposite the transducer could be another issue?. Hull clean and well faired? Then there's the cabling - should be easy to check with vessel stationary....

 

[Spirit (of Glenans)]

Is that why a number of suppliers recommend castor oil?

No, the reason for using castor oil is that it does not go rancid, so it never needs to be replaced.

 

[Spirit (of Glenans)]

this appearing and disappearing, is it the while display going blank or are the numbers being replaced with dashes? If the former I could be the power cable having intermittent breaks of contact, or the internal linear regulator having a fit, in which case NASA can fix it.
Interesting point about the oil clouding up, but I can't see it being the problem

The oil clouds up in the cold because wax is separating out of it, in the same manner that diesel and central heating oil does in winter, if it doesn't have the correct additives. The wax particles float in suspension in the oil and interfere with the functionality of the transducer, similar to the way bubbles from turbulence, or sand/mud stirred up by a propellor would.

 

[steve yates]

Display just goes blank, apart from the E on the lhs, which has always been there.
I’ll get rid of the olive oil and buy some castor oil, not something I have ever shopped for

 

[Sianna]

Garmin suggest filling the in hull tank with marine antifreeze or mineral oil, I used antifreeze without any problems

 

[Rum Run]

Display just goes blank, apart from the E on the lhs, which has always been there.
I’ll get rid of the olive oil and buy some castor oil, not something I have ever shopped for

This sounds like an electronics issue to me, but it would be interesting to see what effect an oil change has. If its urgent and you can't get Castor in time, replacing with ordinary veg oil, which doesn't seem to go cloudy in normal temps, might prove something?

 

[Oily Rag]

When my transducer failed, I made a temporary fitting of the replacement directly to the hull using sikaflex, being careful ensure I hadn't trapped any air. Five years later, it's still there. ?

 

[steve yates]

For the record, the switch to castor oil in the tube worked, depthsounder now working. Even warned me I was out of water coming back up the creek at dusk when I took a wrong cut, just as I ground to a halt