Convex circles on our rudder 1987 53
3 Convex circles on our rudder


Greetings all,

I am the proud owner of Antares (Hull #53-003).  Relizing that Antares is a Frers design I was reluctant to post this here, but found so many warm welcoming responses on the new Swan owners sight that I thought it appropriate to give all of you a query.

Last year just prior to launch during early March, following an 8 week lay up on the hard in RI, immediately after an application of Micron CSC barrier paint, I noticed 3 half dollar sized convex circles in a vertical line along my rudder. They appear to be parrallel to the rudder stock and in the middle third of the rudder each approximately two feet lower than the one above. When sounded with any solid stricking device, hammer included, it's clear that there is a weak attachment of the glass and gelcoat under these three small circles.

We launched with the expectation that the problem would worsen and I would have to contend with it this winter. When we hauled at the end of December the convex circles were gone. The weak spots do however exist and can be identified by sounding.

I suspect that the bond of the glass that comprises the shell of the rudder to the understructure is compromised. I also suspect that the compromise is in a region where foam is directly in contact with the shell.

This finding was disconcerting as Antares' bottom is otherwise pristine. Dry, blister free and as solid as a 20 year old hull can possibly be.

Does anyone have a technical drawing of the rudder for the 53 of this vintage? Does anyone know how the rudders were laid up? Were holes cut into the completed halves to facilitate injection of foam? Has anyone contended/resolved this issue?

I am reluctant to cut a hole into the rudder as I'm concerned about potentially causing more problems than I already have as the rudder is relatively dry.

Is anyone familiar with material science to suggest that a small weep hole to check for the typical ooze will be completely plugged with some West System epoxy to prevent further ingress of water in future.

The bottom line is that I am slightly concerned about the long term corrosive effects of water on the structural integrity of the rudder that might cause a catastrophic failure when at sea far off the beaten path.

Fair Winds
Eric

Dear Eric,
I am sorry, I am not able at all to help you, but I would like you to know everybody is welcome to this website and Forum, and even if Antares is not a Sparkman & Stephens design, she's a Swan, and I do hope someone could help (perhaps Lars, The Professor...!)!
Matteo (38/067 Only You)

Dear Eric

There is no reason to be concerned, what you see is part of the original rudder blade concept. There are conical circular recesses in the blade, and the skin laminate continues also in the recesses. At the bottom of the recesses are flat areas bearing against the stainless flag welded to the aft edge of the stock, with through bolts holding skins and flag together. There are thin covers over the recesses.

A steering system drawing is available from Nautor, or you may prefer to order a complete Owner's Manual with text part and arrangement and system drawings. Contact  technical-service@nautors-swan.com

It would be good to check occasionally whether there is water in the rudder blade, this can be done by drilling a tiny hole at the lowest point. The hole can be sealed with a screw+ mastic, or with epoxy. This check would also give a warning if the stock corrodes inside - there would be lots of rust coming out

Kind regards

Lars

Hi,

Thanks all for the support and the warm welcome.

Lars where would you suggest drilling the hole to check for drainage? How far up from the bottom and how deep? Do you reccomend a hole on each side?

How large an area do I need to fair the epoxy plug to get good confidence that the plug of epoxy will seal the hole to prevent further ingress of water?

Regards

Eric

Dear Eric

Suggest you drill a tiny vertical hole on the centerline at the lowest point of the blade, and seal it with a few drops of epoxy.

If there is water in the blade the leading and trailing edges should be checked for damage. The blade consists of two halves joined along the centerline. Also the joint where the stock enters the blade should be checked for leaks.

Kind regards

Lars