Strike Release Rudder

A very interesting rudder stock which is what I have been thinking of for the day I build my Trimaran. Maneuvering a shoal draft vessel needs this kind of device when maneuvering in dirty water or areas with coral heads and reefs, such as in the islands; and where charting is poor or suspect. Take a look.....

The new Sea Sure Strike Release catamaran rudder stock is the result of a back-to-basics, fundamental design review carried out by leading sailors and engineers. The key design criteria were that the new stock should be: Lighter, Stronger, Stiffer, work better and be more reliable than any existing catamaran stocks on the market.
The new stock meets all of these criteria whilst looking fantastic.

Features;
1. Dual action strike release with no moving parts
2. Off centre pivots, calculated using Ackerman theory
3. Lightweight triple formed Aluminium body for strength and stiffness
4. Latest computer modelling techniques used throughout design process

Manufacturers web site is here

And here is another video for you interest, on the same principle of strike release

Rudder Rebuild

weeping water from rudder

Our Rudder was removed from the sv Solace after investigating some weeping from the rudder. We also drilled into the rudder and discoverd the rudder had a cavity and poured out water.
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

Rudder Shaft Seal Upgrade

The packing gland on the rudder shaft of my Hylas 44 never did prevent water from  coming into the boat; with rate of about a drop every 10 seconds, I wanted something drier; like no water ingress.

First I removed the rudder quadrant to access the packing gland flange and cleaned up both the removable flange, (top left in photo below) and the area to be resealed (left).  I obtained a double lipped seal with stainless steel spring for my shaft which was 2.25 inches. Measuring the flange which use to press down on the packing gland, (and now inverting that flange) the sleeve measured three inches. So a seal of 2.25 ID and 3.00 OD would do it. Then I obtained a reinforced hose of 3.00 ID. I used a silicone hose but you could use a good quality rubber hose.

Next, some hose clips and gasket maker and lithium grease. I used a silicone RTV type gasket maker for motor vehicles. Having removed the packing gland material, I started to assemble my new shaft seal. I only had about 2.75 inches of shaft to work with placing the seal on and the up turned packing gland flange took most of that.
I applied grease down the shaft where the packing gland use to sit and gasket maker to the surface of the flange where the upturned packing gland flange will bolt to.
Slid the flange over the shaft and mated the surfaces and secured with the four bolts.

Grease down shaft & gasket maker applied

As the bolts tightened the RTV squeesed out and I left this for 24 hours to set.
After the RTV had set, the hose was placed over the flange and I applied grease to the seal and inside the hose, pushing the grease as far down as I could get it. Then I cleaned out the surface area to where the seal would sit. This is going to have some of your favorite sealant applied here for the seal. Without the sealant, the seal will tend to slip out of the hose when pressure is applied to the hose clamp.The lower hose clamp was applied and I used my RTV sealant to the OD side of the seal and the ID of the hose. I slipped in the seal to the hose and applied the hose clamp loosely and left for 24 hrs to set before tightening a little bit more.
Finally, everything was reassembled and the boat placed back in the water. I now have a very dry rudder shaft. Now, if I can just get rid of the rain water that comes down the mast.

Grease applied before seal

Costs; $30 for the seal; $18 for the hose; grease and gasket maker $20. Hose clips I had already.
Paul
s/v Solace
http://web.mac.com/paulngina/site_1/Home.html

Finished product