SW 26
Gallery of Seawolf 26 Pictures
  At Rest
  Mast & Rig
  Galleys & Gas
  Engines, Propulsion
  Chart Tables
  Genoa options
  Deck Layout

Jasmine's rudder with stainless bearing prior to painting. Lip (see opposite) already faired in.

Woolfee's lower rudder bearing. This one is mild steel, but most are stainless. Not sure why there is a lip on the leading and trailing edge fo the rudder, but it is present here and was on Rosa's also. I've faired mine in.

Rosa came with a modified rudder by the previous owner. He fitted a lower skeg, presumably to help when drying if resting on his wing keel. I removed the lower skeg and modified the shape a little. Note that Seawolf rudders are foam filled "hollow" rudders, and I suspect the majority will have all the foam saturated with water. This is a weakness, as it could encourage the plates that are welded to the stock inside the rudder to corrode and ultimately to bust. One to keep an eye on!
Rosa's rudder as of 2007. Note the bottom rudder bearing has welded SS plates vertically, allowing bolting through the skeg. Only use marine grade stainless here (316?). I prefer bolting through, even if there is a bit more drag from the bolt heads.

Sooper Trooper's rudder, with more "balance" (some of the blde in front of the pivot) than most. also note the antifouling of the propeller (looks like a maxprop feathing to me). I'm never sure if to antifoul propeller or not.

Shown below is how a Seawolf rudder is constructed, and the problems that can occur to the tang that is welded onto the rudder stock. This can corrode especially over a period of time, if, as it almost always does, seawater gets into the hollow rudder. Seawolf rudders, and probably Cobra ones are made of 2 halves that have the Stainless Steel rudder stock running down through the top of the top section of the rudder. It has a SS tang welded at right angles to the rudder, and this is glassed to one side of the blade before it is joined together. The majority of the stock is above the rudder, and passes through the stern of the boat. A small part, perhaps 10 mm passes out of the bottom of the top part of the rudder, and this fits into the bearing on the skeg. How the two halves of the rudder were bonded together I am unsure in those days. Some rudders were filled with foam, probably injected after joining, others just hollow. The foam did not really help, as it eventually soaks water if it can get it. It is extremely hard to stop water getting in where the SS stock enters and exits the rudder:

The top of Woolfee's rudder, cut away on the starboard side, viewed from the trailing edge and slightly to starboard. Note the hole where the SS stock exits the hollow rudder blade in the top right of this picture, and the "box" of glass to hold the SS tang
Same rudder, viewed from port, with the "box" that holds the tang cut away also

SS rudder stock, showing where the SS tang was welded to the stock. This part would not normally be visible, and would be inside the rudder.
The SS tang that was welded and then glassed to the stock. Note only the weld has been damaged by the corrosion.


View of the top of the rudder, ground away a bit. The hole where the stock normally goes through the rudder blade has become oval as it was free to move around on the stock and wear when the tang bust.

Since this is a problem for most boats built at that time, I'm not sure what the solution is. When Rosa was surveyed, her rudder was saturated, but because she was only launched in 2000, not so likely to suffer corrosion. But the surveyor suggested I checked the other boats in the yard with his water meter, and to my amazment, almost all showed very high levels of water in the rudders. Interestingly the wooden rudders showed least water ingress. Anyone with a good solution please advise. Possiby a hole cut near the weld to inspect for corrosion?


Here are some progress photo's of Woolfee's new tangs. The difficult bit for the welder was lining the tangs up with the tiller. Eventually we decided to fit it all into the rudder with the tiller attached and spot a small weld to hold the tangs in the right place. They are just under twice the width of the originals and about 1mm thicker. The extra width gives a longer weld. I decided to go for a single wide tang otherwise my patented cunning plan for inserting the welded stock into the rudder would not have worked without cutting a hole in the top of the rudder. You can see that the stock can be fed up through the top hole at an angle because this is no longer a tight fit. The new top bush is put on the stock before feeding it up into the rudder and there is just enough room to clear the lower bush and fit the stock down into it.

The next job is to epoxy and glass in the tang then the upper bush - see below:

The area behind the tang is built up with epoxy and filler powder (microfibres), ready for glassing in place. Note the nitrile "O" ring above the lower bush, ready to be pushed down to further waterproof
The tang glassed into place with woven cloth (12 layers), and the bushes also bonded with epoxy and filler powders, followed by glass cloth. Nitrile rings in slid into the bush to add that little extra sealing qulity, and bonded with epoxy. A further O-ring was epoxied into the rudder from outside (both top and bottom) making 6 O-rings in total. As Jonathan says, "If that doesn't waterproof the rudder, I give up!"

The plywood (glass mat/epoxy coated) frame epoxied on to the underside of the cut out with epoxy and microfibres. The four screws held it in place until the epoxy had set and allowed me to adjust the depth of the frame so that when the panel was placed onto the frame, it was flush with the rest of the rudder.
The rudder filled with expanding foam. If sealed properly, the foam won't be needed! Jonathan says that before this work, when the rudder was hollow, he could feel the water moving in the rudder when the boat was pounding along.

The panel placed on a bed of epoxy and microfibres. Because of the curvature of the rudder surface, there was a big enough gap between the panel and the frame to allow sufficient epoxy mix for bonding.
The join between the panel and the rudder was gouged out into a U shape with a Dremel and filled with more epoxy and microfibres.

The join was then faired level using epoxy plus low density filler and sanded using wet and dry paper. Because he had also built up the edge of the rudder with several layers of woven tape, the indentation around the rudder (a feature of some Seawolf 26 rudders) became slightly more pronounced so this was also faired in. Congratulations to Jonathan for all the work, reckon the boat will go better for the fairing also.