Sticking Log Transducer - what type of o'ring lube?

RobW

RobW

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Sticking Log Transducer - what type of o\'ring lube?

Just after some quick advice - I have a Navman 3100 log transducer - standard plastic through hull fitting. Ever since I installed it its been a real battle to withdraw the transducer from the through hull fitting - it just seems to seize in.

I have tried everything, so am finally about to replace the through hull fitting in belief that the original must be destorted or faulty in some way.

The transducer itself has a couple of o'rings, what I would like to know is what these should be lubricated with? I understand that o'rings should be lubricated with a contrasting material - ie. if you have silicone based o'rings DON'T use a silicone based lube. HOWEVER - how do you know what they are made of in the first place - have tried to ask Plastimo, but no help there they could not even tell me what size of o'rings to order for replacements, never mind do anything useful like supply them!

Any advice much appreciated!

Rob
 
Re: Sticking Log Transducer - what type of o\'ring lube?

If I remember rightly silicon lube is correct.Halfords sell a pack of O rings that will fit 2" to 1/2"
 
Re: Sticking Log Transducer - what type of o\'ring lube?

Yes the lubrication will make a big difference to ease of sliding the transducer in and out. However if you had not made the hole in thehul big enough and had forced the outer tube into place then that may have induced distortion into the outer tube causing difficulty in sliding the transducer in. Check memory. goed luck olewill
 
Re: Sticking Log Transducer - what type of o\'ring lube?

As the O-rings are probably nitrile, you can use any lubricant - I use PTFE in silicone.

I'd not bother to change the fitting - it's most unlikely to be that.

More likely is that someone, in an excess of H&S care has fitted slightly oversize rings in the mistaken impression it will be "safer".

Try lubrication first, remove and replace with the blanking plug every time to leave the boat. That way the need to remove and clean is mitigated and you keep the whole lot working well.
 
Re: Sticking Log Transducer - what type of o\'ring lube?

Agree but put the blanking plug in before you make that last cuppa, clean up and lock the boat up. That way you get to see if you have put it in properly and there aren't any leaks. A boat can take in a lot of water through seepage over a couple of weeks
 
Re: Sticking Log Transducer - what type of o\'ring lube?

You may not need to take the thing right out; if our paddle wheel sticks I slacken the cap slightly, and turn the paddle wheel through 180 degrees and back a couple of times. This usually frees the paddle wheel.
 
Re: Sticking Log Transducer - what type of o\'ring lube?

Thanks for your reply - I have previously tried vasoline, synthetic silicone based grease, tried wet and dry to abrade the surface of the hull fittings - so I think the distorted skin fitting is the most likely cause - only have my self to blame - either the hole was too tight, or I do have a slight reputation for over tighteing things! (as proven by my failure to remove the retaining nut on the fitting today!


It is really odd though - it literally seizes - you can put the log down, with it able to rotate and move up and down in the fitting easily. Go out for an hours sail, come back in, try to raise the log and it will be stuck solid. The force you have to put on it to remove the fitting is frightening - I am convinced it will beak off one day, so last season I just leave it down - its only a matter of time before a crane sling breaks the paddle wheel!

Thanks again.

Rob
 
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