Fouling of Knotmeter Impeller with Zebra Mussels

Aug 20, 2013
173
Beneteau 311 Port Clinton, OH (Lake Erie)
If you have the boat hauled, take out the depth one, too, just to make sure it is not frozen in place.. Give the face a coat of that special paint for transducers.
For some reason, I don't seem to have fouling trouble with the depth transducer. Maybe the plastic repels critters, or perhaps my monthly scrubbing gets it. But I will try loosening it up if I can get to it. For the knotmeter sensor, I have to hang down over the ledge at the front of the V-berth and work between the bulkhead and the water tank.
 
Jun 9, 2004
615
Catalina 385 Marquette. Mi
In the Chesapeake Bay we don't have those Zebras, but in the warmer weather we get mud shrimp and some other small critters that can build fast enough from one weekend to the next that the impellor will not rotate until pulled and cleaned. After a weekend cruise I pull the wheel out and put the dummy in till the following week.

Edit to add: I do paint the part that sticks out of the hull, but not the wheel itself. Use the same paint you'd put on the face of the depth transducer.
Holy crap! I thought we had a zebra mussel issue when ONE lodged in my impeller and jammed it.. that’s crazy.
On Superior?
 

Joe

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Jun 1, 2004
7,999
Catalina 27 Mission Bay, San Diego
My depth tranducer is not removable.... no moving parts.. flush with bottom... bottom paint right over it... no issue. My speed transducer is NEVER left in.... it would foul in a matter of days otherwise(even with Desitin). I used to swap it in everytime I took the boat out.... not that much water... but as someone else mentioned it helps to lubricate it once in a while..... That said... I have quit using it and will eventually replace with a N2K compatible device.. I have become completely dependent on the gps and the chartplotter's current and tide data... really don't miss the speed log at all.
 

Joe

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Jun 1, 2004
7,999
Catalina 27 Mission Bay, San Diego
I can use the GPS for speed but without a good knotmeter reading the apparent wind readings are miscalculated.
I'm hoping you mean true wind calculations.... since no calculation required for apparent wind... that is what you feel... but anyway... why not use the gps speed for your true wind calculations... You should be able to network the apparent wind speed/direction data into your gps/chartplotter with a conversion cable.... then indicate set boat speed data source to gps.... rather than log. You must have a networking chart plotter for this... if not. it may be time to consider upgrading..
 
Aug 20, 2013
173
Beneteau 311 Port Clinton, OH (Lake Erie)
I'm hoping you mean true wind calculations.... since no calculation required for apparent wind... that is what you feel... but anyway... why not use the gps speed for your true wind calculations... You should be able to network the apparent wind speed/direction data into your gps/chartplotter with a conversion cable....
Joe, you are correct; the wind instruments measure apparent wind and calculate true wind. That’s what I meant but not what I wrote.

I have a small, older Garmin GPS with a 3x4” screen on the boat that helps me find marks and avoid reefs, but not a modern chart plotter. I never felt the need for one. I keep the applicable chart out when I sail (either on the seat in the cabin or under a cushion next to me in the cockpit) for reference when I’m sailing someplace a little tricky.

I think my next step for electronics probably will be to install an AIS system, including a transponder.
 
Jan 22, 2008
198
Montgomery 17, Venture of Newport, Mirror sailing dinghy, El Toro sailing dinghy Mound, MN -- Lake Minnetonka
Holy crap! I thought we had a zebra mussel issue when ONE lodged in my impeller and jammed it.. that’s crazy.
I'm on the same lake as you and my impeller gets clogged even worse than the OP. But then I don't sail as fast as you do. :)
 
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Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
I'm on the same lake as you and my impeller gets clogged even worse than the OP. But then I don't sail as fast as you do. :)
Wow. How fresh is your bottom paint? BlueJ gets fresh VC17 every year, and I'm sure they don't like hanging around all that copper.

Its also true that the mussels are clustered. Maybe more where you are on the upper lake?
 

DougM

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Jul 24, 2005
2,242
Beneteau 323 Manistee, MI
What are you feeding those things in Lake Erie?
I’m in northern Lake Michigan and I don’t see accumulaton like that even on pilings or my steel seawall.
I use VC17 on the bottom and repaint annually. The only place I see any zebra mussels is on the top of the rudder when I haul out in the fall, probably because I don’t get enough paint there. Those mussels are only about the size of a matchhead.
I was also going to comment that it seems like every year there are fewer of them, and I am wondering if there are some natural predators that have begun to take a liking to them at least in the larval stage.
 
Aug 20, 2013
173
Beneteau 311 Port Clinton, OH (Lake Erie)
The water in Lake Erie is much warmer than Lake Michigan, upper ‘70’s or even 80 in August. Also, the west end especially has a high runoff load from northern Ohio, and southeast Michigan. These areas are both densely populated and have a large amount of agricultural runoff. Woods are pretty sparse. Eastern Ontario borders the other side but it is not so densely populated with animals and people.

Lake Huron gets few zebra mussels.

The mussels are nasty on the pilings and rocks. They are razor sharp. If you have to dive on the boat or retrieve something that fell in, you’ll probably get all cut up and those sharp cuts bleed for a while. The mussels are worse than I remember barnacles being where I grew up on the East Coast.
 
May 25, 2012
4,333
john alden caravelle 42 sturgeon bay, wis
..... they always mention the farmers and forget that a HUGE part of the problem is all the crap suburbanites dump on their lawns to get a sterile looking lawn.
 
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Aug 20, 2013
173
Beneteau 311 Port Clinton, OH (Lake Erie)
If we could use more “crap”, as in manure, and less commercial fertilizer on our lawns and crops (assuming proper application procedures), it would reduce the total load (BOD) on the waterways.

It also doesn’t help that many, if not most, cities and towns bypass their wastewater treatment plants when overrun by rain.
 
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Aug 20, 2013
173
Beneteau 311 Port Clinton, OH (Lake Erie)
Follow-Up - Fall Haulout. I had several good suggestions last spring about how to treat my knotmeter impeller (paddlewheel) so that I would not have a huge lump of zebra mussels in the fall (see initial post with picture). I ended up just painting the impeller with the same VC-17 I use every year on the hull. I put the paint on sparingly so I didn't gum up the spinning of the impeller and I made sure it spun freely before I launched the boat. At haulout the impeller looked pretty good. Only one mussel was stuck near the impeller. While I did get an occasional stoppage of the knotmeter when leaving the dock, it always cleared out after sailing a little while. I scrubbed the bottom a couple times over the season with a mesh cloth manipulated from the deck by two people.

Thank you forum for your help.
 
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Kopite

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Mar 11, 2015
110
Catalina 27 Monroe MI
Boat is up on the hard. Glad I used VC17 vs whatever my neighbor uses !
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FDL S2

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Jun 29, 2014
469
S2 7.3 Fond du Lac
Boat is up on the hard. Glad I used VC17 vs whatever my neighbor uses !
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I use petit sr21 or vc17 (whichever is on sale) which I have always been told are basically the same. I paint the paddle wheel when I bottom paint and I have no zebra mussels on my hull and have only had a them on the speed paddle wheel twice in seven years of ownership-both times were after a few weeks of not sailing. I pulled the through hull, put the dummy plug in and cleaned it (once while sailing single hand).
 
Jun 21, 2004
2,532
Beneteau 343 Slidell, LA
I leave mine out and install it when I am using the boat. My Raymarine /Airmar paddle wheel transducer has the flapper valve that drastically reduced water ingress when removing or installing the unit. Definitely easier than cleaning the paddle wheel on a boat that is in water year around.
 

DaveJ

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Apr 2, 2013
449
Catalina 310 Niagara-on-the-Lake
Original poster is in Lake Erie, I'm in Lake Ontario (down stream), I have never seen zebra mussels like his. We had a cottage on Georgian Bay (up stream), 15 years ago there were mussels but not many now, and many years ago we had the mussels in Lake Ontario....but not many now. So what's going on with the zebra mussels???? I thought that mother nature figured out a way to counteract them, as mother nature often diminishes invasive species, is this a encore for the zebra mussels? I hope not....

dj