Rudder Paint and Zincs?

[Rockjumper]

Hi all. Finally getting bottom paint on my C28. The shop asked whether I wanted to paint the rudder. They also recommended adding a pancake zinc to the rudder. I'm going to use some galvanizing spray on the prop.

Any thoughts on the advisability of painting the rudder? I haven't seen many rudder zincs on the Fluid Motion boats. It looks like it's probably more common to add a transom anode bonded to the system but, that's a bit more of a pain to install.

 

[Red Raven]

I use galvanizing spray on the rudder and have found it works well. I don’t spray the prop because it seems to stay clean as long as the boat is used at least every few weeks. I also have a pancake zinc on the rudder. Another option besides a transom zinc is to add collar zincs to the swim grid brackets. They should already be bonded.

Curt

 

[Ralf H]

Hi Rockjumper,

That's pretty much a personal choice and depends on how aggressive the waters are where you keep your boat. Not sure of the percentages, but there are plenty of owners who don't paint the rudder or add the pancake zinc, etc. but add the transom anode if not already installed. The anode is easily mounted on the starboard transom and then having the through bolts connected to the bonding system at the rudder post. Pretty simple and effective. That's how we've built many boats but it's your choice. Hope this helps.

Cheers,

Ralf

 

[FlyMeAway]

Other option is painting your rudder with propspeed not bottom paint. I know other boaters who have gone this route.

 

[knotflying]

I have used cold galvanized on the prop and rudder. I bought a quart of it and brush it on. A quart will last a very long time. I prefer to brush on since you can get a thicker coat and the prep protection is much easier than spray.

 

[1Harrison]

At the beginning of the season three seasons ago, while doing bottom paint we had VELOX applied to the running gear. When we left to boatyard I was able to go 2 knots faster than ever before and turn 200 RPM more than before. It's a little pricy and lasted two years. Lola B goes in for bottom paint next month and we plan to apply VELOX again.

 

[BB marine]

When I painted my C26 bottom when it was new I used Pettit barrier coat to seal the gel and provide a good adhesion of bottom paint to the hull. At the same time I prepped all the under water metal hardware to apply the epoxy barrier coat to it too. This included the stainless steel keel shoe, thru hull fittings, swim platform supports, rudder and rudder box, thrust gear housings and trim tabs. I applied three thin coats to the bottom and all named components. Then applied Vivid bottom paint to all components. This system worked well and the paint adhered well to the metal. There was the need to touch up the rudder yearly because the prop thrust caused cavitation on one side of the rudder and would wear away the vivid and a small section of the barrier coat. The trim tabs continually would bubble the paint I believe because they were stand alone ( not bonded) there was some galvanic reactions. The thruster housings and all other metals looked like new and held the paint. I did not paint the prop and never had any growth at all. We are usually using the boat if it is in the water. I also pull the boat at least every three months for a hull cleaning and wax.

I have the same process done on my Mainship 34 Pilot. The only difference is I am leaving the trim tabs alone and just plan on scrubbing them if I see growth.

I did not install an anode to the rudder. I did not feel it was needed. Having all the metal components sealed with the epoxy eliminates them from being exposed. The only active anode on the boat was the prop and trim tab anode. The thruster anode rarely has any erosion. The hull anode no erosion. The prop and trim tab anodes did erode but not much. The photo below shows 6 months of fresh, brackish and saltwater erosion. I contribute much of this because there was no metal exposed to protect.

These anodes are Aluminum alloy. I do not use Zinc anodes.
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[Rockjumper]

Thanks all, many great recommendations! I also saw that Airmar has some water based transducer antifouling paint. Might try that on the plastic thruster impellers.