Installation of a Shaft Brush on a R-31

[Newtugnut]

When we first hauled out Blue Horizon's after only 11 months in the water - noticed alot of wear on the various zincs on the boat.

We have a galvanic isolator, and the Yacht CLub does cathodic measurements of all the boats each year - to ensure that boats are not contributing to a corrosion problem.

After discussion with the factory and 'experts' at the Yacht club we decided to install a shaft brush. I had to modify an existing commerical one since the exposed shaft on an R31 is only about 1"

I have pictures (before and after) which show what I did, as shown below in sequence.

 

[Newtugnut]

Forgot to show the before pic prior to modifying the shaft brush.

You can see I had to shave down the width of the brush to accommodate the narrow space occupied by the shaft and that I had to rotate the brush itself 90 degrees.

 

[baz]

Last year I also installed a shaft brush on our R-25. We had a lot more exposed shaft than your R-31 so I had no reason to shave the brush as you had to. My shaft brush installation post is http://www.tugnuts.com/viewtopic.php?f=5&t=2539&p=18657&hilit=shaft+brush#p18657 but the photos have since expired. If anyone wishes for me to repost the photos then let me know.

BTW… your green ground/bonding wire attached to the shaft brush seems a little on the light side IMO. I used 8 gauge.

My shaft brush is attached/bonded to the engine and a large plate anode attached to the starboard side transom, just below the water line.

The shaft brush, transom plate anode, swim step bracing donut anodes and a GI have made quite a difference to the rate at which our R-25's under water anodes erode. Our diver will be making their rounds this week so will then have a full year of data for the anode replacements. Mind you, the swim step anodes protect just the bracing struts as the struts are not bonded to the boat's bonding system.