weeping water from rudder |
Upon removal we also saw the rudder stock had corroded where the packing gland material sat, and with the ingress of water into the rudder, also wondered about the quality of the stainless form inside. It was decided to rebuild the rudder from the ground up.
Corrosion on the rudder stock at Picture on right.
We also changed to a seal rather than packing and readers can read that under our blogs in the rudder section. All dimensions of the "old rudder" where carefully recorded, so as to ensure as near as possible, a duplication. Photo's where also taken where necessary.
Cutting into the rudder reveled nothing more than "shop sweepings" with a little resin. A large cavity for water to sit in and probably weeped it's way in at the top of the rudder, where the rudder stock joins the GRP. The rudder stock was cut away from the GRP and sent into an engineering shop to have the shaft repaired where the corrosion was. After completing that, they made a new SS form/frame for the rudder and attached that to the rudder stock
The rebuilt rudder stock with new frame attached and ready for phase 2.
A closed cell foam was fashioned in two halves to the dimensions of the old rudder, and machined with router so the new rudder stock would sit snugly inside the foam "shape".
To the right, the photo shows how the frame sits inside the foam prior to gluing the two halves together.
The photo to the left show the two halves under weights while the gluing process drys. Note, the two halves make one rectangular shape. and the outer shape is yet to take place.
The rudder is then planed to shape, allowing for the thickness of the new fibreglass covering.
Once the final shapeing is complete, two groves are machined into each side.
Hardwood strips where placed into these groves and they sat against the stainless frame and level with the foam surface. This is to prevent movement of the stainless frame inside the softer foam.
Finally, the process of glassing over the foam begins. When completed a descent bead of sealant was applied where the rudder stock "disappears" into the glassed rudder blade. This job is not for those without some experience. It is slow and tedious work to get things right. About 6 weeks for completion. We probably now have a lighter rudder, and feel safer sailing across oceans knowing our rudder is right.
Finished and installed |