Log transducer removal

P

porth

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101
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If your log stops working, and afouled impeller is the likely cause, is it bloody daft to take out said transducer with the boat in the water, or is it just a (very) wet experience?!
 
Not daft at all, done it several times. Make sure you have either a proper cap to fit on the tube when the transducer is out, or something to stuff in the tube (not a wood plug - it will probably damage the tube). You'd be surprised how slowly the water comes out, you certainly won't see an "Old Faithfull" style gusher! You will need to mop up the water that does get in of course, but it's usually not too much.
 
We do this fairly regularly - I find it handy to have a rag to hold over the hole temporarily until you're ready with the bung. One good bit of advice is to try not to do it underway as in my experience that tends to lead to you becoming far wetter! Alternatively we've often managed to clear the impeller just by rotating the transducer itself when underway.
 
Anything that involves having a hole in the bottom of the boat below water line whilst in the water, unless absolutely necessary, is madness.
One stripped/dropped screw leaves your vessel vulnerable. Beaching or lifting is only safe method.
If your really brave a quick dip over the side to clear it is possible /forums/images/graemlins/blush.gif
 
Most removable logs these days have a couple of O rings to hold the water at bay and some other form of locater to prevent the body of the transducer from moving up the hole. Therefore it is simply a matter of getting the body into the hole plus at least one O ring, then all water ingress should stop. I have done this innumerable times - after all that is what this sytem is designed to do. Furthermore, I always do it before drying out, as I have a blank plug that I can use to fill the hole. Best advice is to make sure that the one going in is in the best hand, and use the other hand for the removal of the other, thus it is easier to locate.

My log doesnt have any screws or other items to strip.

If unsure about doing this practice, a few times when boat is out of the water.

What is madness is using your boat when the log is not performing correctly when a simple operation will enable accurate log readings for your navigation. /forums/images/graemlins/confused.gif
 
on some boats, the log/paddlewheel hole has a rubber flap, so that when the cylinder is withdrawn water ingress is minimal. Even without this it's not really very very wet experience, but you need a blank plug ready and/or wooden bung before taking the thing out. Oh, and if the idea is to clean the thing up, scraping around hardly ever fixes it. A better idea is to take the paddle wheel out and replace with a proper blank every time you leave the boat.

I note the post about opening up the hole with boat in water being madness, and this indeed avoids any problems at all....
 
I live in Norway, its dark, blowing a strong gale, and the water temp is around 4 degrees C. I reckon I'll drop the swimming idea!
Thanks for all your help folks, I have your replies and lawyers will be in touch if she sinks! /forums/images/graemlins/smile.gif
 
You don't even need to remove the transducer if you get a sudden blockage. While sailing, just loosen the nut, turn the log 180 degrees (so it is running backwards), hold for a short while, then replace back in the original position. Common trick that I use on the east coast.
 
Well I definitely get an old faithful when I do mine. I reckon I ship a couple of gallons of oggin - still fairly easy to mop up though.
 
We had both log and depth transducer removed whilst on a flotilla holiday - water was nice and warm - the purpose was to wash out a smelly bilge though...

It was on a Moody S31 and the head of water was <5 inches. We had to leave it out for over a minute before there was sufficient water to wash out the bilges and it was easy to put a blank in ... I would now happily do this on my own boat - although only when moored or at anchor. (Liquid vanish made the boat smell loverly /forums/images/graemlins/grin.gif) Not sure on the weight - but it was probably >5tons (ne1 with a MS31?)

I would say that - if disaster struck and the housing broke leaving you unable to fix the transducer in place you would have plenty of time to change, get a wooden plug, jump over the side and plug up the whole before your boat sank .. especially if you turn on the bilge pump first....
 
The boat did not sink, so you are all safe from my army of highly paid lawyers. Thanks again for the advice. /forums/images/graemlins/smile.gif
 
One trick is to get the crew to turn the boat on it's beam ends so that transducer is in less water or even out of the water. It does make a difference which tack you are on if the transducer is not centre mounted. Before throwing the whole system away I used to only fit the paddle for actual sailing fitting the blank when on mooring. My old Smiths had a peg so that it could only go in one way no rotating it to go backwards. Yes the half litre of water to mop up was a menace. regards will
 
Way I did it ...

Have blank plug to hand .... the kit to fit the tranmsducer comes with a blanking cap to screw on in place of the log transducer .... Unscrew the log till it is just about to come free. Now change hands so that your best hand is ready with blanking cap / plug. With wrong hand unscrew vlog and lift out smartly .... slapping cap / plug into place and screw on. Why change hands ? I tried putting the blanking cap with my left hand - I'm right handed - and I had trouble ..... and as water comes in you feel a bit 'pushed' !!
Normally I had just a few litres at worst ..... if that. Best about a cupful.
 
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