Cleaning the paddle wheel while under way...

Rich Stidger · Aug 10, 2013

Got any video Brian?

They say a picture is worth a thousand words. A video of your paddle-wheel incident could be priceless.......

BTW, is it clean now?

Hello Below · Aug 10, 2013

FourPoints said:
Most people know that cleaning the paddle wheel while moving a couple knots usually results in less water coming in than when sitting the dock, well I just wanted to let everyone know that cleaning it at 7 kts results in WAY more water than at the dock....

I guess the extra pressure from the bow wave while near max semi displacement hull speed is to blame, lesson learned, I need dry clothes now, and a beer.

Yip. Did the same thing 2 weeks ago with the same logic and had similar results. To add insult to injury, a few days later my knot meter displayed only 0.00 while underway. This time, while alongside, I, pulled the Airmar triducer and found it as clean as a whistle. After a number of posts to Raymarine forum I finally took the suggestion to check the connections at the back of the display and sure enough found the shield had broken off at the crimp. A new terminal fixed the problem.

s sauer · Aug 10, 2013

Cleaning Paddle wheel under way

We get enough slime growing on the bottom& paddle wheel of the Knot meter to sometimes stop it from spinning. Fortunately the paddle wheel is located ahead of the keel, so while motoring or sailing, I can go forward to the bow pulpit and deploy a dock line forward so it slides under the bow of boat while I hold each end above and outside the life lines. Picture this like a 'jump rope'. let the line slide aft until it contacts the paddle wheel, then bring it forward and aft a couple times until the Knot meter starts registering speed. Only the dock line gets wet!

Ted · Aug 10, 2013

cleaning the paddle wheel

Airmar makes a through hull fitting for their transducers that has a little trap door built into it. As soon as you remove the transducer, the trap door immediately closes. Only a small amount of water enters the boat. You don't have to replace your transducer, only the through hull portion. They can also be used for depth transducers if you have a removable type. I went with a CS4500 ultrasonic speed transducer this season and it also fits the through hull fitting with the trap door. Unexpected cold salt water showers while you're fully clothed is no fun.

Rich Stidger · Aug 10, 2013

s sauer said:
<snip> I can go forward to the bow pulpit and deploy a dock line forward so it slides under the bow of boat while I hold each end above and outside the life lines. Picture this like a 'jump rope'. let the line slide aft until it contacts the paddle wheel, then bring it forward and aft a couple times until the Knot meter starts registering speed. Only the dock line gets wet!

I have seen more than a couple of the paddle wheels damaged and your technique, while effective, may one day cause the paddle to become disconnected and lost or just broken. However, I think the paddles are more commonly damaged if they are left in the hull and the travel lift straps crush them at haul-out or lift-in.

Just sayin....

Hello Below · Aug 10, 2013

Ted said:
Airmar makes a through hull fitting for their transducers that has a little trap door built into it. As soon as you remove the transducer, the trap door immediately closes. Only a small amount of water enters the boat. You don't have to replace your transducer, only the through hull portion. They can also be used for depth transducers if you have a removable type. I went with a CS4500 ultrasonic speed transducer this season and it also fits the through hull fitting with the trap door. Unexpected cold salt water showers while you're fully clothed is no fun.

Not sure that the Airmar fitting with the flapper is all that great. It work for 3 or 4 times but the last 2 times it didn't (while under power and while alongside). Maybe I buggered it up by removing the transducer while under power and over pressurizing something. Even when you could hear it thunk into place, a fair amount of water ingress resulted. I will have to have a look see when I haul the boat next spring to see if something is out of place.

timsha · Aug 11, 2013

s sauer said:
We get enough slime growing on the bottom& paddle wheel of the Knot meter to sometimes stop it from spinning. Fortunately the paddle wheel is located ahead of the keel, so while motoring or sailing, I can go forward to the bow pulpit and deploy a dock line forward so it slides under the bow of boat while I hold each end above and outside the life lines. Picture this like a 'jump rope'. let the line slide aft until it contacts the paddle wheel, then bring it forward and aft a couple times until the Knot meter starts registering speed. Only the dock line gets wet!

wouldn't the dock line get antifoul all over it? also if motoring I would be worried about the dock line getting caught in the prop while retrieving or if the line slipped?

All U Get · Aug 11, 2013

My Airmar lets in some water, too. I can usually swap the plug and get less than a quart of water in the bilge. I try to keep the paddle wheel out if we're not using the boat and just have to remember to put it in before dropping the mooring pendants. I changed it a few times while moving at 4+kts and it's very impressive.

Joe23455 · Aug 11, 2013

The most sobering thought I got from removing the paddle wheel for cleaning a few times is the fact that a plan must be in some order if the
hull is ever compromised ie: being holed, or having a thru hull fail

The force of water coming in a 1 1/2" hole is impressive and seeing the clear water thru the hole a little unnerving but still a good way to unfoul the wheel

.
I keep a rubber mallet and wood plugs close by my emergency stuff.

Rich Stidger · Aug 11, 2013

Like others I remove the paddle wheel when I am leaving the boat for a few days and replace it before sailing. However if I am at a destination I leave the paddle wheel in place. Upon leaving sometimes the wheel is not turning. What I do is to loosen the securing ring and move the paddle wheel transducer up and down 5-6 times and then re-tighten the ring. This almost always clears any debris and the wheel now runs free. Very little water comes in with this action.

I agree that the sealing flap doesn't seal perfectly or instantly either, but mine lets in water volume like a drinking fountain, and if I remove the paddle quickly the flap snaps into place. It seems to require water force and volume to get behind the flap to seat it.

Brian D · Aug 11, 2013

I haven't done this yet, but I was thinking an industrial size trash bag or plastic painters tarp under the boat before removing the wheel. I figure that the outside water pressure would push the plastic over the hole with very little water coming in. I will have to try that one day.

Mine is currently out but I want to put it back in for an upcoming trip.

Gudenuph · Aug 11, 2013

An 8" dia. piece of PVC about 7" long, roughly fitted and caulked to the hull around the transducer unit contains the small amount of water ingress between the removal of the paddle wheel assembly and the insertion of the plug on our O'Day 25. This was a dockside effort, hasn't been attempted underway.
FWIW, Geohan

kmart · Aug 11, 2013

Rich Stidger said:
Like others I remove the paddle wheel when I am leaving the boat for a few days and replace it before sailing. However if I am at a destination I leave the paddle wheel in place. Upon leaving sometimes the wheel is not turning. What I do is to loosen the securing ring and move the paddle wheel transducer up and down 5-6 times and then re-tighten the ring. This almost always clears any debris and the wheel now runs free. Very little water comes in with this action.

I agree that the sealing flap doesn't seal perfectly or instantly either, but mine lets in water volume like a drinking fountain, and if I remove the paddle quickly the flap snaps into place. It seems to require water force and volume to get behind the flap to seat it.

So if you remove the paddle wheel when u r away for a few days.... I'm guessing you have some sort of plug? My depth gauge has a such a plug. But my paddle wheel does not. Did you make a plug?

Nom De Guerre · Aug 11, 2013

kmart said:
So if you remove the paddle wheel when u r away for a few days.... I'm guessing you have some sort of plug? My depth gauge has a such a plug. But my paddle wheel does not. Did you make a plug?

Are you certain you're using the plug for the right transducer? The depth doesn't need one as it's flush with the outside of the hull. The point of the plug for the speed is so that you can swap the protruding transducer/wheel with the flush plug when hauling out (otherwise the slings can crush the speed's wheel paddles).

Rich Stidger · Aug 11, 2013

kmart said:
So if you remove the paddle wheel when u r away for a few days.... I'm guessing you have some sort of plug? My depth gauge has a such a plug. But my paddle wheel does not. Did you make a plug?

Yup. See pix below for the paddle wheel and the corresponding plug. The plug was supplied and it has a locking ring just like the paddle wheel.

Squidd · Aug 11, 2013

Good info...I was just contemplating this very move this week end...

My knotmeter has been pretty good up til now but two weeks ago it stopped...found it was the paddle when I pulled it up on the trailer, spun it and was working again last weekend and most of this trip, but then it quit half way thru...

Yes I can wait till I pull it out on the trailer again, (did and it works again) but would have liked to have pulled it on the lake and resumed use of wheel while we were out there...

I do have the wooden plugs on board...might have to give it a try if it goes out again...

fstbttms · Aug 11, 2013

Rich Stidger said:
I have seen more than a couple of the paddle wheels damaged and your technique...

He ain't doing his bottom paint any favors either.

DougM · Aug 12, 2013

My transducer paddlewheel gets baby zebra mussels caught in it! Sometimes just tapping it with a rubber mallet while underway clears it...
Otherwise, I just pull the transducer and clean it with a toothpick, I have an Airmar transducer and it came with a companion plug attached to the transducer cable, I can pull the transducer and replace it with the plug, and only get about a quart of water in the boat. I just keep a big towel handy to soak it up.

Cleaning the paddle wheel while under way...

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