? Blister on Rudder 34

Aug 7, 2018
179
Catalina 350 Great Sodus Bay, Lake Ontario
I stopped to check on my boat this am and saw this on the rudder. Its about 1.2 " across. How do I repair it? Anything I should do now before spring?
rudder photo.jpg
Is it water intrusion?
 
Jun 3, 2004
890
Hunter 34 Toronto, Ontario Canada
I had a larger bulge on my rudder when I bought the boat 16 years ago. I am sure it was water inside that had frozen while on the hard.
I ground the area out getting down to where the foam was white- about 1 inch down,( by the look of your picture that might be shallower) then filled it back in with layers of cloth and epoxy, cut in increasingly large pieces until almost even with the rest of the surface, then filled with epoxy mixed with filler and sanded down to smooth. I coated only with VC 17 for several years then I re did the whole bottom and finished with Interlux 2000e.
I also drilled 2 1/4 inch holes in the bottom when I first did it and every year I fill them with bedding compound before launch and at haulout i pull the filler out so the water can drain. There always seems to be about 1/4 cup of water drain out even though I have sealed around the shaft. The good thing is no more bulges.
 
Aug 7, 2018
179
Catalina 350 Great Sodus Bay, Lake Ontario
Thanks Richard. I'll get on this in the spring. That's what I suspected the problem was. I'll have the glass work out when I repair a "spare hole" from an old transducer. The good new? Its good old Lake Ontario water. See you out on the water. Thanks again.

David
 
Jan 7, 2011
4,723
Oday 322 East Chicago, IN
The PO of my O’Day 322 had a rudder repair done similar to what Richard explained. I have owned the boat for about 5 years now, and haven’t seen a reoccurrence.

Greg
 

Joe

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Jun 1, 2004
7,999
Catalina 27 Mission Bay, San Diego
Just for clarification, it's not a blister.