Thruster Propeller Removal

[swillmerchant]

Does anyone know how to remove the propeller from the bow and stern thrusters? I removed the nut, but still couldn't get them out. The tubes are covered in barnacles, so I really need to get in there and sand so I can put on a new coat of bottom paint before we launch. Any advice would be much appreciated.
Thanks,
Doug

 

[HRowland]

Doug,
I had the same issue. The Imtra rep at the Defender Warehouse sale said to use a wood dowel and small hammer. Place the dowel against the back side of the prop close to the gear leg and tap lightly with the hammer. Turn the prop and repeat. He assured me that I would break the prop before damaging the gears or gear leg.
After tapping in a few spots they popped off. Note there is a washer under the nut, this popped out once the prop freed up.
Sidepower recommends using marine grease on the spline when re-installing the prop to make future removal easier. They also suggest removing the prop annually.

Howard

 

[LADYBUG TOO]

Doug,

Here's another suggestion for after you get them off. We used nuts and washers to mount the two thruster propellers on an all-thread rod. After cleaning them, we chucked the assembly in our power drill and dipped the assembly into the can of bottom paint. We let the excess drip back into the can and then gave the props a slight spin with the drill in another can to evenly distribute the paint onto the propellers. We repeated the process after drying time to get a good build up of bottom paint on the props. No barnacles on the props after a year in the water. We also made a tool for cleaning the thruster tunnels while in the water. It is a small flat blade screwdriver heated and bent to almost 90 degrees, then ground to a slightly rounded end so as to not score the thruster tunnel wall. I generally clean them as often as possible. Even here in Florida, the water gets colder than I want to get into. We have found that the gear head collects barnacles faster than the tunnel wall. Since we leave her in the water all year except for bottom painting, I spend a lot of time on the end of a hookah hose (the under water kind!).

Pat & Carolyn, Ladybug, Too

 

[swillmerchant]

Thanks Howard, Pat, and Carolyn. I'll try that tomorrow when I can get out again. I like the tool idea for cleaning and for coating the prop. Our prop tunnels were nearly blocked by a mass of blue mussels (not big enough to eat though).

I'll be priming and painting the trim tabs, rudder, prop, and swim platform supports this year. Last year, we had ~2" of hydrozoas, mussels, barnacles, algae, and sea squirts covering nearly everything metal under water. We lost 3-4 knots by the end of the season. This year, we're priming with Pettit underwater metal kit and putting bottom paint (Pettit Hydrocoat Eco) over top.

This weekend was the first weekend that the Boston area could really get out and prepare our boats. It was really one of the first days that it was both sunny AND above 50 degrees. Luckily the wind was under 20 knots so we could get the tarp off without being blown away. Weather windows have been hard to come by this season so far.

 

[Automaticman865]

Doug,
I am right around the corner from you at the Willows. On our Cutwater 28 I painted all the underwater metal first with 2 coats of Blue water barriershield barrier coat primer. Then used the Blue water copper shield , 2 coats on the metal and 1 coat on the bottom. I've been boating here since the mid 80's and never seen it come out of the water this clean. Even the boat yard was shocked. You're welcome to see the boat as I've not prepped it yet.
Stuart

 

[LADYBUG TOO]

Stuart,

Did you see any change in your zinc performance. I am sure that you did not paint the zincs. The reason I asked is that I painted the rudder, prop, and all underwater metal except, of course, the zincs. My prop nut zinc was gone in less than a month. I also did not do a good primer job so soon lost the paint on the rudder and prop. I think we will use the same primer as you did next time to get better adhesion.

Pat & Carolyn, Ladybug, Too

 

[Automaticman865]

Ladybug Too,
When I got my Cutwater it did not have a hull zinc. The factory has since then been installing them on the newer builds. My prop zinc had a limited life like a lollypop in a candy store. I was using the hanging guppy but I was always worried I would wrap it around the prop. Then I installed an 8 lb Diver Plate zinc, which made a huge difference in the prop zinc life. You should see the plate, it really took a beating. McMaster-Carr is a great resource for all sorts of hardware for the install.
I used that same paint sequence on the thrusters metal and found that my zincs also lasted longer.
Btw on the thruster tunnels scotch brite does a great job.

Stuart