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Post by so40gtb on Mar 28, 2011 0:14:52 GMT
Has anyone attempted replacement of an Airmar/Raymarine depth transducer (for ST60 or similar instrument)?
My depth sounder died last season. All connections and such checked good and other Tridata instrument functions all work normally.
My old one is the plastic fixed-mount type. The replacement has the removable element and plug, so a future transducer failure will not necessitate through-hull replacement and I can put in the plug when the boat is on the hard and getting the annual coat of bottom paint.
I wasn't able to get the threaded collar to back off today (awkward angle), though I'll try again next weekend with a better tool inventory. I do wonder whether I'll need to break apart the old unit into pieces in order to extract it.
--Karl
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Post by MalcolmP on Mar 28, 2011 18:06:10 GMT
Hi Karl
I have changed a plastic speed transducer support before, which is probably easier as there is the clearance hole you can work from
The sikaflex that is used to bed the units in is amazingly strong - even after I had removed the locking ring and cleaned the threads etc the unit would not budge even with reasonable force via clump hammer and wooden block was used - rather than stress the hull I therefore opted to cut it out simply by radial cuts through the central hole - obviously take care to stop when you get to the hull - the unit could then be broken out in several pieces before the hole was cleaned up and the new unit rebonded in
On reassembly whilst orientation is not important on the depth transducer it is critical for the paddle wheel - getting it aligned then tightening the compression ring when there is excess sealant about is challenging - if I remember there is a flat section where you can grip the transducer body with a slip wrench or similar - if not you will need to think carefully how to hold the unit securely whist you tighten it up - doesn't have to be overtightened though - as the plastic will crack
I imagine you should be able to simply drill through the unit to allow a saw blade to be inserted
Do take some pictures and let us know how it all works out
Malcolm
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Post by so40gtb on Apr 1, 2011 3:53:29 GMT
Fortunately, my speed transducer was the removable-sleeve type, so replacement upon its demise at age 7 did not entail removal of the thru-hull. All I needed to do was to acquire the replacement paddle-wheel unit, plug it in, and splice the cable.
So far, I've been able to cut away much of the bedding sealant on the depth transducer thru-hull, at least inside the hull.
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Post by so40gtb on Apr 16, 2011 2:50:05 GMT
Project nearly complete.
Don't even think about removing either the depth or speed transducer thru-hull assemblies intact. It's not going to happen.
The first obstacle is the ring nut that holds the unit in tension thru the hull. It won't budge because of the use of sealant within its threads (as per the Airmar instructions). I had to cut it off using a Dremel tool's cutting disc (cut thru it at 3 points, pry the gapped arcs loose with a screwdriver and plastic hammer).
Even with the ring nut off, the thru-hull wouldn't budge.
The next obstacle is the sealant used thru the hull, which seems as strong as the ring nut. The most practical means of breaking the cylinder loose was the application of a large adjustable-jaw wrench (Channelock) to the body of the cylinder, ruining the plastic threads, after applying "encouragement" at the hull in the forms of a sealant solvent and a heat gun. A good pipe wrench will achieve the same result, but tear up more threads!
Once the old unit was out, removal of old excess sealant and such was straightforward and uneventful.
Installation of the new thru-hull sleeve was straightforward, as well, but two caveats: a) follow the Airmar "bedding" directions religiously, ensuring plenty of sealant on all surfaces and spread into the threads of the thru-hull cylinder and b) make sure you have extra nitrile gloves, as at least one will suffer a finger opening while spreading sealant around. I used 3M 4200 sealant.
I ended up replacing both the depth sounder and log/speed sensor thru-hulls, as the latter's top was chipped during the early efforts at breaking loose the former. Fortunately, I had a spare aboard!
--Karl
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Post by rxc on Apr 16, 2011 11:24:55 GMT
Before you replace the transducer, do a full reset on the system. I had something like this happen to me once, and was all prepared to haul the boat (in the Azores!) to replace the transducer, and the local Raymarine service guy told me that transducers are quite robust and difficult to break.
Short story - I opened the book and found the instructions for the factory reset, and voila! the depth sensor came back to life. I then had to re-initialize all of the other instruments and the autopilot, but it caused me to see that the autopilot had not been set up properly by the original commissioning dealer. So, in the end, it was worth it.
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Post by Don Reaves on Apr 16, 2011 13:03:06 GMT
I'll have to try that trick to see if I can get the temperature gauge working on my ST60. It's been telling me that the lake water is 120 degrees F for the past three seasons!
The manual indicates that I should replace the transducer to correct the problem. In my case, a replacement unit wouldn't require anything more than running new wires and mounting it in the existing thru-hull, but the expense never seemed worth it for a function I don't really care about.
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Post by sailbleu on Apr 16, 2011 13:22:20 GMT
I'll have to try that trick to see if I can get the temperature gauge working on my ST60. It's been telling me that the lake water is 120 degrees F for the past three seasons! The manual indicates that I should replace the transducer to correct the problem. In my case, a replacement unit wouldn't require anything more than running new wires and mounting it in the existing thru-hull, but the expense never seemed worth it for a function I don't really care about. I believe you can adjust the measurement in the instrument itself. But I'm sure you thought of that yourself. Try selecting celcius and see if the offset is the same. Greetz |
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Post by Don Reaves on Apr 17, 2011 12:50:31 GMT
I've tried all the adjustments possible regarding the temperature gauge. There's no way you can make a 50 degree F adjustment! That's as it should be, I'm sure.
Don
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