Tech Wiki

Rust Streaks

Why do I Have Rust Streaks Going Down My Rudder? How do I Repair a Water Soaked Rudder?

Q: I have noticed in some of the FAQ that a sign of water in the rudder is rust streaks, and that this could be expensive to repair. My 34 is pulled every year (Toronto Canada) and over the last two years I have noticed, as the months progress, rust streaks running from the rudder post and down the side of the rudder. Is this a warning of water in the post or above the rudder? What can I do to prevent or repair before it becomes worse? Any advice would be appreciated.

John Potts, Pottsluck #1064


I pulled the cap off my rudder and could see water inside. So I took a 5-foot scrap hose and duct taped it to the shop vac and sucked it out. I found 12 oz of water or about 8 inches deep in the column. I measure down 53 3/4 inches before I hit the bottom of this tube. Does anyone know the length of the shaft (post) on the C34 1986 models? I would like to know if the is right where the post goes into the rudder. I also need to know if this is the cause of rust streaks. Shaft and rudder are in perfect shape but I wish I had done this before the winter. I guess this will be another job at each haul out.

Capt Al Watson, Kindred Spirit #55


Capt Al, Sorry you just missed me being able to take this measurement. I have #840 1989 winged keel and I just capped off the rudder after filling post with epoxy due to same water condition. Can't give exact depth of post now but recall it was also around 53 inches. Catalina drawings have the post going much further down into the rudder and from my experience drilling holes in rudder to drain out any water, the bottom of post is about a foot from the bottom of the rudder which is where the rusty water exited after drilling the hole. My rudder symptoms were rust running down side of rudder originating from the spot where the rudder meets the post. There was no evidence of any rust coming from spots anywhere else until I drilled holes to relieve the water content in the rudder itself. Once drilled the rust was coming most from holes close to bottom of rudder. This is an important job, April 2000, Cruising World p96 talks about water in rudders and C34 Tech notes talk about filling the post and sealing the post/rudder joint. Good luck!

Skip, Virtual Reality #840