Wet Rudder

[Aquaria]

Hello All!

Our GRP-constructed Rudder is collecting water, no matter what I did to it.

The construction: a stainless steel rudder shaft, the rudder is out of fibreglass.

The rudder is held at the bottom (sitting behind a skeg), the point where the shaft leaves the rudder at the top end lies under the CWL.

I know that the connection between GRP and metal is always a critical point.

And this is what I did in the past:

The first time I took out the whole rudder, took it home, drilled holes in it, sat it on a central heating radiator for a whole winter to let it dry out, laminated a couple more layers to make the construction stronger (using the WEST-epoxit system), shaped a groove around the shaft on both ends and filled it with a sealing compound for underwater use (Pantera), closed this with a last fine layer of mats and hoped, that this should keep the rudder watertight...

Two years later: water in the rudder. This time cleaning the grooves, letting it dry out over the winter, sealing them again. With the same long term result: water in the rudder...

Now I start again!

For two reasons water in the rudder is not so good: we know that wet fibreglass over a long time is weakening the construction (delamination) and I have seen one rudder that split during winter storage at freezing temperatures (that due to global warming becomes less of a problem here...).

Do you have an idea what else I can do to keep the water out for more than just a year or two?

Uwe

SY AQUARIA

[Swagman]

Its always tough keeping water out of any hollow void you leave submerged, especially with a stainless to glass joint as you have with your rudder stock.

I can only suggest you consider a flexible as opposed to rigid sealant twix the stock and the glass once you've gone through the dry out process one more time. A shame you can't get inside the rudder and fill it 100% with foam.........

Good luck

JOHN

[MMNETSEA]

Hello Uwe,

Having gone through the same problem myself where the rudder suffered from hydrolysis,

while the hull had no problems.

Here is a really good article on the issues including solutions :- HYDROLYSIS

Richard

[Aquaria]

Thank you both for the responce.

Looks as if I might use the time in the shed (until Spring 2009) to dry out the rudder and renew the sealant once again between glass aund stock and hope that it holds another couple years...

And special thanks for the article, Richard! I did not know that nowadays a barrier coat of Vinylester resins is the state of art instead of formerly used epoxies! 13 years ago I applied the WEST-System epoxy coating and now it showes blisters between coating and gelcoat. (Happy that the coating I applied myself performed well for such a long time, but not amused about the costs of a new barrier coat...) But now I start to understand why the coating showed blisters, which disappeared within 6 week after Aquaria went on the dry, while the hull structure remained dry, as moisture measurements showed. So, this article comes just in time before getting a new barrier coat that has to be done too this year.

Uwe

SY AQUARIA