PS Advisor October 1, 2000 Issue

PS Advisor 10/01/00

Rudder Leaks
I read your rudder-rebuild article (February 1, 2000) with interest since I own a 1972 Ranger 33 with an original rudder. I have a couple of comments and questions.

You mention that water enters the rudder at the joint between the glass and the stock and the problem of sealing this area was a debated issue. What was the debate about and how was it resolved? My view is that due to the stresses and different expansion coefficients of the materials, permanent effective sealing of this joint is impossible. Instead, why not assume that water will enter here over the long term and install some kind of drain in the bottom of the rudder to let it get out while on the hard?

My rudder shows evidence of past expansion with a couple of areas of small cracks in the gelcoat. I assume this occurred because one year the boat was hauled late, there was an early freeze and the water inside had nowhere to go other than to expand the shell. I have drilled a small hole in the bottom of the rudder which allows the water to drip out once the boat is hauled—usually I get a half cup or so over a couple of days. When it is in the water I seal it with a screw and neoprene washer. What problems do you see with this approach to the “water-in-rudder problem”?

I keep my boat in upstate New York and am new to sailing. Curious about the relative state of my rudder I cruised the yard observing other ones. It seemed that at least half, if not more, showed signs of gelcoat cracking, which I assume must be caused by the same freezing effect. Why hasn’t this problem been resolved by boat designers?

I am also assuming that since the water dripping out of my rudder is clear with no rust, I needn’t have serious worries about internal deterioration of the steel. Do you agree?

Finally, what about creating a solid rudder as opposed to filling it with foam? Is there any necessity for the rudder to have as much positive buoyancy as the foam provides or would a rudder filled with an epoxy filler perform equally well while providing more internal strength?

Kerry Edwards
Ranger 33 Sandpiper
via email


You’re right; the different coefficients of expansion make a perfect seal of the stainless steel rudder and fiberglass shell difficult. When we were trying to choose the best caulk, we got several answers, hence the “controversy.” Several persons recommended the structural adhesive Plexus, in part because it is reputed to stick well to stainless. But it is not readily available in small quantities. Meanwhile, several boatbuilders suggested 3M 5200, though a reader has since observed that adhesion to stainless is not one of its strong points. In the end, we went with 3M 5200.

Drilling a hole in the bottom of the rudder after haulout each fall is a good idea. We did this every year but rather than install a screw and neoprene washer as you did, we simply filled it with epoxy and microballoons, noting the location for drilling out the following year. If the amount drained becomes excessive, however, it is probably time to reseal the rudder/stock joint.

As you point out, this is a common problem among older boats—ticking time bombs.

The only really different solution builders have arrived at is to build the rudderstocks of carbon fiber and glass and bond them to the shell. This works, but is not a viable option for owners of old boats as the carbon fiber stocks are invariably larger in diameter than our old stainless stocks, which would require reworking the rudder tubes, packing glands, etc.

Clear water is a good sign, probably indicating that the webs are stainless and not mild steel. We wouldn’t worry about corrosion in your case.

As for making a solid rudder, this would be okay except that rudders should ideally be neutrally buoyant. The first reason is to minimize wear on the bearings. The second is that heavy rudders produce lee helm, and buoyant rudders weather helm.

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