Bow Thruster Protection

It's been over a year since I have been using this idea and all has gone well. So I thought I would share. Every time my diver came to clean my boat bottom he would scrape and chip away at the bow thruster impellers and housing to remove the growth. Using an angled chunk of metal and a screw driver he would attack the blades and get off the barnacles and such. Had to be a better way. The bow thruster is the ideal marine growth laboratory for marine growth. Small fish, oysters and barnacles can live in the tube without fear of larger predators. The sea water drifts back and forth with the motion of the bow to bring in the food. Its a great life for the little critters.
So I measured my bow thruster tube, seven inches, and went to my local upholstery shop and purchased a piece of 5" High Density Foam. Then took a serrated bread knife and cut two eight inch diameter pieces. Filled a bucket of water and added Dawn Dish Soap. Saturated the foam and put them into my bow thruster openings.
No more sea growth. No more scraping of the bow thruster. Lots more power from my bow thruster. If you don's want to get wet when you pull them out, add a center line with a starboard backing. Pull them out when your ready to go.
Don't add any chemicals or chlorine tablets to keep the bow thruster really clean. Chemicals will "Burn" the High Density Foam. I know, I tried that.

How did you put the saturated foam into the bow thruster opening? Did it require you to get into the water each time you used your boat?

Seabreeze, you beat me to both those questions?

Excellent idea. Should be able to push them in with a pole.

I don't understand the " Lots more power from my bow thruster." comment.... these things aren't in there when you are using the boat are they? You are getting the power as a result of not having the prop fouled, correct?
Sounds like a solution for a boat that sits for long periods of time unused...?

I thought I had lost a prop because of the power I had lost from boat sitting for two months.

When we pulled it the tunnel was full of growth. Not major, but blades are small enough it blocked full thrust.

So this was a great timely thread.

antifoul thrusters and you shouldnt have issues

Yes. More power due to clean blades.
Foam plugs put in by swimming up to the thruster. Use them when boat is going to sit for more than a few weeks.
Antifoul paint seems to not last. Maybe because the thruster blades are plastic and flex when running. But the paint on our Sidepower was gone after a month of cruising.

Pgitug said:

Yes. More power due to clean blades.
Foam plugs put in by swimming up to the thruster. Use them when boat is going to sit for more than a few weeks.
Antifoul paint seems to not last. Maybe because the thruster blades are plastic and flex when running. But the paint on our Sidepower was gone after a month of cruising.

Click to expand...

its all in the application process

Pgitug said:

...
Foam plugs put in by swimming up to the thruster. Use them when boat is going to sit for more than a few weeks.
Antifoul paint seems to not last.

Click to expand...

There was an awful story posted a while ago about a hull cleaner in the water and thrusters activating. If doing this in a marina, or perhaps anywhere, take care.
You don`t specify the type of disappearing a/f, a hard type would be preferable.

BruceK said:

There was an awful story posted a while ago about a hull cleaner in the water and thrusters activating. If doing this in a marina, or perhaps anywhere, take care.
You don`t specify the type of disappearing a/f, a hard type would be preferable.

Click to expand...

You are so right about a positive power shut off. We have one. It’s always in the off position. On only during docking maneuvers.
A diver on the east coast was killed when a hydraulic bow thruster was tested while the diver was cleaning the bottom of this large motor vessel. Very sad.

My thruster seems to have lost about 1/3 of its power. I’m sure it’s all clogged up.

My marina water is pretty gross so I would like to do this, but don’t want to get into the water. Maybe I could install it from the dinghy.