Delaminated Rudder Chapter II

[Irwin32]

I took the predominant advise and pulled the rudder - a lot easier than I anticipated. Using a dremel I cut around the area and pulled off the outer skin. Inside was not what I expected. When I have read about foam cores I imagined a foam like material not terribly unlike styrofoam or Great Stuff. The core of my rudder seems to be some type of epoxy or polyester. It is hard - I figured foam would be somewhat easy to cut, etc. There are some random glass fibers in the mix. It is almost like Irwin took a batch of left over resin to use as the core. Any thoughts? I am considering using West to fill some of the voids that exist in the core.

[capnjim02]

what you found is open cell structural foam. strong but sucks up water like a sponge. It has its uses but I don''t like it. in a rudder you have two things working against you. you have a structural foam and FRP that have a differant coefficient of expansion than the stainless rudder stock. this always creates a crack where the stock enters the rudder and provides a path for water to get inside the rudder. I wish i had a definative answer for all but i don''t. obviously if the rudder fills with water its subject to freezing and bursting if it doesn''t drain. it can also cause constant blistering because it never drys out. On mine I finally bite the bullet, removed the rudder, split it and removed all the open cell foam. I then used FRP to make a much larger load area for the foam. glassed it back together and filled with closed cell foam. its not as strong as the open cell but I don''t have a problem with water in the rudder now. this is a large project but if your handy doable.
the key is to make sure that you have increased the load area enough to assure that you won''t crush the closed cell foam inside. I did this 8 years ago and havn''t had any problems since.
good luck.

[Irwin32]

My core looks nothing like foam nor does it have any structure to it that could be called cells. I don''t think crushing it is a problem as it is very hard.

[fupa]

I have a tartan 34''and have some gelcoat cracks that run across the nonskid area in my cockpit. I was wondering if anyone knew a way to replace the nonskid pattern after I fix the cracks. The crack repairs I can do, I''ve done them with success in the smooth gelcoat on my boat, but the nonskid stumps me. I really don''t want to sand it all off and paint it with a nonskid powder. I have heard of some builders being able to send you a small mold to lay down on the wet gelcoat to reestablish the nonskid, was this a fable or am I on the right track.