Tuesday, April 2, 2013

New Rudder Tale

We talked about our selection process to have a new rudder built here. This post will continue with what happened after shipping off the rudder stock. Competetion Composites Inc (CCI) computer generated a pattern for the rudder based on the German Frers design drawings, machine cut the foam core, and attached it to our rudder stock.

Based on their experience, the rudder was rebuilt with unidirectional fiberglass reinforcement laid in the channel alongside the stainless post, extending down towards the tip of the rudder. This should help eliminate the "hard point" where the post ends and the rudder suddenly becomes more flexible, the area where the original fiberglass skin cracked.

The foam core was overlaid with fiberglass cloth and then sealed into plastic for vacuum infusion of the resin - basically a tube to a vacuum pump was put on one side, and a tube to the resin on the other, allowing very even clamping pressure all over the cloth, and a light, even coating of resin for the cloth.

Construction after the resin cures consists of smoothly fairing the rudder,

sanding and priming, and then CCI crated and shipped the rudder back to us. We waited until the hull was painted and the shaft cutless bearing was installed before opening the crate to inspect.

All looked well, so we removed the new lower bearing which was machined for us, and installed it into the rudder tube. The boatyard used their transporter to lift the boat, and the rudder was lifted into place. In 2008 we did this with a come-along, but the boatyard did it with six workers. I installed the ring and pin that the rudder hangs from, and then they chocked the boat back up, ready for more bottom paint!

Rough costs (US$): $5400 for the new rudder and bearing, $1500 in shipping, and $1200 for dropping the rudder, crates for the shaft outbound and rudder inbound, outbound and inbound brokerage in Grenada, Grenada ground transport.

Comparing the new rudder to the old: There is much more hydrodynamic fairing in the new foil, a flare to match the hull curve is apparent whereas this flare must have disappeared over the series of repairs I can only imagine the old rudder must have undergone. Alignment with the shaft appears better by several degress based on needing to reprogram the autopilot after carefully ensuring the rudder was aligned with the keel. We haven't noticed any difference in handling yet, but are looking forward to seeing how she responds once we get sailing.

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