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1979 C&C 30 Mk I - 2QM15
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I'm guessing it's probably marine beasties or just algae, but everytime I take my boat out, the speed sensor paddle wheel is stuck and doesn't work. After a couple hours out, it finally free's up and I get to see how fast I'm going on the way back to the slip. (This is the paddle wheel sensor that came with the Raymarine Tridata ST60).

Are there any options for fixing this so it works all the time instead of intermittently like this?

Or do all paddle wheels gum up like this on a regular basis?

* If it makes any difference, I'm in the upper Chesapeake Bay *
 

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paddle wheel problem too !

I have the same Raymarine 60 set up and it only worked a few weeks after bringing my boat down to Annapolis from the "fresh" water of Harve de Grace. I have tried pulling it out (that can get the heart racing !) when its not in use, spary lube and it continues to be inconsistent at best. Most of the time it just reads 0.0...

There must be a better system that is available that can be swapped out in the same thru hull fitting. I too look for help in solving this 'currently' worthless device, which also throws off the wind vane speed.

Greg
Dragonfly
Annapolis
 

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I'm guessing it's probably marine beasties or just algae, but everytime I take my boat out, the speed sensor paddle wheel is stuck and doesn't work. After a couple hours out, it finally free's up and I get to see how fast I'm going on the way back to the slip. (This is the paddle wheel sensor that came with the Raymarine Tridata ST60).

Are there any options for fixing this so it works all the time instead of intermittently like this?

Or do all paddle wheels gum up like this on a regular basis?

* If it makes any difference, I'm in the upper Chesapeake Bay *
We gave up on the paddle wheel about ten years ago. It works fine when free of growth, but in the Chesapeake "free of growth" only lasts as long as the boat is moving.

We just leave the blank in all season now.
 

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Here in the Mediterranean paddle wheels are commonly effected by fouling. They can be cleaned, but many people are not prepared for the effort involved to keep them accurate. When my instuments were damaged by lightening I opted to go with 2 depth units (one is a fishfinder) which provides redudency for this important transducer.
Speed is provided by the GPS. There is little tide here and I have been impressed by the acuarcy and usufullness of SOG and the derived displays such as true wind. Much more usefull than an inacurate paddle wheel.
Be aware Raymarine St60 instruments will not give true wind from SOG,but other systems will.
An alternative is an ultrasonic speed transducer, expensive and some reports of unreliability, but newer transducers receive good reports if your speed is under 10K.
 

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1979 C&C 30 Mk I - 2QM15
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Discussion Starter #5 (Edited)
I have tried pulling it out (that can get the heart racing !)

I'm considering pulling it out cleaning it, but I'm a little leery because I keep hearing people like you say that it freaks them out when they do it. So how much water comes into the boat during the swap? And does it just pour in relatively slowly like a gallon per minute? Or are we talking firehose velocity, wet decks, and a full bilge in the time it takes to make the swap?

---

I found this stuff Transducer Antifouling Paint that claims it's specifically for antifouling on transducers. Which incidentally is what Raymarine recommends:

"To prevent fouling of the paddle wheel we would recommend that a thin coating of water-based anti fouling is applied to the paddle wheel itself."

But I would think that a spray on antifouling paint like Trilux Prop & Drive Spray Paint would allow you to put on a thinner, even coat than a brush on type.
 

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i just cleaned mine last weekend for the first time when down in your neck of the woods ( annapolis city dock) and it is easy. when i pulled it maybe a 1/2 gallon came in, but i did not have the plug in hand. when i put it back maybe 2 cups came in.

what you need to do is pull the pin, start it moving with both hands. once its moving pick up the plug with the spare hand i used my left to pull as i am right handed. then pull it out with the left hand shove the plug or wheel in with the right. it will be slightly stuck the first time you try to take it out, thats why you will need both hands to get it moving. make sure you put the pin in with the plug so it does not pop out.

the hardest part of the whole thing is getting the pin lined up.
 

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We have to leave ours out when NOT sailing or clean it once a week it has the BIG hole and requires a fast hand with the blank plug :)
 

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Smearing the o ring with a light film of silicone grease facilitates installation of the replacement plug and the paddle whell unit after cleaning. They'll be easier to align and remove also.
 

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Pulling the transducer really isn't a big deal even if you don't have the blank. There is a flapper valve of sorts that stops most of the water from entering the boat. You really would be surprised how little water comes in.
When reinstalling coating the O-rings with a bit dielectric or similar will help in future removal. When sliding the transducer back in place make sure you correctly align back into the notches. The transducer has an arrow embossed in the plastic (difficult to see) make sure it's pointing forward.
I keep mine in working order, along with the GPS when entering passes and such you can compare the two at a glance and know which way the tide is running and how fast.
Bill,
 

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We have a Standard Horizon SL60 knotmeter/log using a paddlewheel transducer, which I suspect is similar to the RayMarine version. It can be cleaned by pressing out the pin and removing the paddlewheel, which give access to the cavity. A little bleach kills the growies and a few minutes soak in LimeAway takes care of any barnacles. We then spay the paddle, cavity and pin with SailKote several times to build up a fair coating and then “lube” the cavity and paddlewheel with Neosporin antibiotic cream which discourages growth. The foregoing treatment seems to last several months at a time even in the warm water of southwest Florida during the summer months.

FWIW...<O:p</O:p
 

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Borrow a bottle of nail polish from the admiral, clean it with acetone (including the brush) and fill it with antifouling paint. When you paint the bottom of your boat, paint the paddle also with that small brush. Keep the bottle in the boat. Although you do not need any adjustment of speed, check what your display shows with your actual speed on water. You might find it by travelling to and fro a known distance at constant engine revolution and reading your mean speed from the GPS or by directly calculating it. Adjust your display accordingly. If the paddle gives up again, remove it from inside the boat and repaint it.
 

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Try a thin coating of Vaseline on the paddle wheel, not to much but enough to coat, using a cotton swab or similar. This will keep the growth off for much longer than not. Since learning this tip I find that I need to pull the paddle wheel about once every month. (Rock Creek, Chesapeake Bay) I would NOT put anti fouling on it!!

FWIW I don't find pulling the through hulls a big deal, especially with the flapper that slows the flow of water, but then I have three electric bilge pumps, and two manual pumps :)

BTW, most all the transducers used theses days by Raymarine, Tacktick, etc are the same, Airmar I think?
 

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Maybe you should follow the mfg's instructions -- at least for what NOT to do. I wouldn't use any paint on there that has a clean-up recommendation of something that contains mostly xylene. That's what that drive spray you linked calls for.

Here's what Airmar says in the install manual:
"Antifouling Paint
Marine growth can accumulate rapidly on the sensor’s surface reducing
performance within weeks. Surfaces exposed to salt water
must
be coated
with antifouling paint. Use
water
-
based
or
mineral spirits
based
antifouling paint only.
Never
use ketone based paint, since ketones can
attack many plastics possibly damaging the sensor.
It is easiest to apply antifouling paint before installing the sensor, but allow
sufficient drying time. Reapply paint every 6 months or at the beginning of
each boating season. Paint the following surfaces (see Figure 1):
• Outside wall of the paddlewheel insert below the lower O-ring
• Paddlewheel cavity
• Paddlewheel
• Exterior lip of the housing and valve assembly
• Bore of the valve assembly up 30mm (1-1/4")
• Blanking plug below the lower O-ring including the exposed end"

Vaseline sounds safe and interesting. There is one board member here that uses it as a prop antifoulant.
 
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