C-27 Rudder Stuff

[deisher6]

I knew from the last haul out two years ago that there was blistering under the fiberglass skin on Windrunner's rudder.  When the rudder was off the boat and in the sun there were several hand size 1/8 inch high blisters.  The rudder also felt heavy.  I expected some water intrusion.  Not knowing much else about the rudders except what is on this blog and a history of some rudder problems on early models, decided to replace the rudder during this summers haul out.

When we received the new rudder from Hutchins there was a letter from Foss Foam Products of Florida containing instructions on how to prepare the rudder for service.  I called the company for more information:  Received some pointers on preparation, barrier coat and painting. Two points stand out, paint the rudder a light color to minimize the heat absorbed, this made sense from my experience with the old rudder.  The second was that the rudder would be structurally sound without the fiberglass skin. I assume that this was 'for awhile'.

After putting 4 coats of barrier  and 2 coats of bottom paint on the new rudder I weighed them.  The old rudder weighed 54 lbs, the new 44 lbs.  I expected that there was about a gallon of water inside the old rudder.

With a Dremmel rotary saw I cut the old rudder up in 3-5 inch strips parallel to the bottom.

[deisher6]

The Dewmel saw would not cut all the way through the rudder from both sides, even at the bottom.  So I beat off the piece with a small sledge.  There seem to be three layers, the innermost is hard granular I was reminded of salt as found in a salt mine.  The middle layer is smaller granules.  The outer layer is the only one easily recognizable as fiberglass.  The rudder was hard to break off even after cutting through from both sides.

I am not sure of what caused the brown spots.  They did not appear to be wet or damp.

[deisher6]

I expected to run into steel much lower in the rudder structure. The rudder post runs 20 inches into the rudder.  There at least one flat SS structure running from the post aft in the rudder.  I assume that the black stuff is some sort of oxidation?  The post and rudder were firmly set into the casting.  The rudder post was not centered in the rudder at the lower end.

I drove a screwdriver into the casting alongside the flat structure and the casting was definitely wet, as seen in the last flick.

At this point I had had enough fun.  I am assured that the rudder is a pretty tough casting.  The old one would have probably lasted another 30 years.

During this haul out I also replaced the old bronze prop shaft with a SS one, had the prop checked and statically balanced, and replaced the shaft log.  Wes's description of replacing the cutlass bearing covers that operation well.

Hope that this was informative.

Smooth Sailin'

regards charlie

[Razor]

Very interesting. You and Wes never cease to amaze me! Is she back in the water yet?

[deisher6]

Hey Terry:
Should be back in the water Tuesday...then back ready to go by the end of the week.  Need to let the hull regain its shape before tuning the rigging and aligning the engine.

Very much looking forward to sailing with you and Cool Change.  BTW you should see Wes's boat,,,it is looking too nice to sail.

See you soon on the water.

Smooth Sailing

regards charlie

[relamb]

My rudder had a few tiny cracks which seeped water out when I sanded for bottom paint, so I determined that my rudder was waterlogged.
I drilled a 1/4" drain hole near the bottom, and another vent hole at the top, and let it drain out. 
Then (a suggestion recommended by a marine surveyor for another water intrusion issue on another boat) I taped my shop vac to the drain hole with duct tape, to suck out whatever was left and draw air through the vent hole to dry it out, for most of a day.
After that, I expoxied shut the vent hole, repaired the tiny cracks and nicks in the rudder edge, and used my air compressor to pressurize the rudder a little through the drain hole. I  slathered the rudder with soapy water looking for air bubbles.  The leak was at the top, where the shaft went into the rudder.
Could not really get at that joint easily with the rudder installed, but I tried to caulk it as best I could until someday the rudder is dropped.
I decided that things were fine with the rudder, if I need to winterize the boat I will drill another drain and vent so ice doesn't expand and fracture the rudder.  However, the boat has been in the Midwest for 25 years, and that hasn't happened so far, the prior owner had it setting outside every winter.  I only noticed the hairline cracks seeping water out when I had stripped the rudder completely and sanded it for a new expoxy barrier coat.  The bottom paint may have been enough to seal it off.

[deisher6]

Hey Rick:
Very neat way of tracking down your moisture problem. 

The rudder that I destructed did not really appear to be wet: no dampness, dripping, etc.  The only moisture that I saw was when I drove a screwdriver into the casting around the stainless steel infrastructure.  As you san see in the last flick some liquid came out.

I agree that the water enters from around the rudder post.  I tried to seal that part up with barrier coat and paint.  I also cut a 3.5 inch washer out of 1/4 inch Starboard and installed it between the rudder and the hull.

You are right  when you say things are fine.....the rudders are tough.

Thanks for your thoughts.  By the way rudders are pretty easy to put on and take off, especially with hand on the outside.

Smooth Sailing

regards charlie

[wes]

Just finished my own rudder repair and thought I'd share my experience too. I had the rudder off the boat already because I was doing a full bottom job, and because I needed to pull the prop shaft to replace the cutlass bearing and stuffing box (can't do those things with the rudder in place unfortunately). I found several problems with my 1988 rudder:

- Numerous blisters, the smallest the size of a dime and the largest the size of the palm of your hand.
- Seam around the perimeter was beginning to open up.
- Seal between the top of the rudder and the steel shaft was opening up.

I probably have some water intrusion, but the rudder seemed incredibly structurally sound so I opted not to tear it open or take other extreme measures to dry it out. Here's what I did:

1. Repaired blisters by grinding them out, drying, cleaning with acetone, filling with epoxy based fairing compound (I used Interlux WaterTite). Then laminated a 4" band of West System 727 heavy 15 oz biaxial glass tape around the perimeter using WEST System 105/205 epoxy, slightly thickened with West 405. This seals the problematic seam and also provides extra protection for this vulnerable edge in the case of groundings etc.



2. Faired the reinforced edge. I used epoxy based fairing compound; tried Interlux WaterTite on one side and West System 105/205 thickened with 407 filler on the other. Both worked very well. The WaterTite is more difficult to sand, but stronger. The 105/205/407 is exceptionally easy to sand, almost too easy to over-sand if you aren't careful.



3. Applied 5 coats of Interlux 2000e epoxy barrier coat. Minimum dry time is 3 hours but I allowed an overnight dry, except for the last coat.



4. While 5th coat was still in the "thumbprint" stage (about 30 min. after applying), I applied the first coat of antifouling paint in order to get a chemical bond with the green epoxy. I used Interlux Micron CSC. (note I ran the 2000e barrier coat about 4" up the steel shaft to provide a base for antifouling paint for the portion of the shaft that's submerged in the water. Not a good idea to put antifouling on an un-primed shaft due to possibility of galvanic corrosion.)



5. Used a Dremel tool to open up a clean gap around the steel shaft entry point, kind of a "moat" about 3/16" wide and deep. I filled this with 3M 5200 adhesive sealant. Not normally a fan of 5200 because it's so difficult to remove later, but I wanted the maximum possible adhesion and flexibility, plus this joint will be underwater all the time.



6. Applied two more coats of antifouling - so three total. That's it! Hope this repair lasts forever. If not, I'll go Charlie's route and order a new rudder. This repair turned out to be time consuming - several weeks of evening work including waiting for various stages to dry/cure.

[deisher6]

Hey Wes:
As usual, good thorough well thought out work....especially the 5200 around the rudder post.  I wish that I would have thought of that.  Because of the way that I glassed in the bottom fitting of the rudder tube on the boat,  I was very conscious of the paint on the bottom of the rudder post.  On Windrunner I think that the paint would have caused some binding in the rudder action.  The lower end of the old rudder post was pretty shiny.

Windrunner steers pretty well.  Finally going to get a chance to try it out the next couple of days.

Thanks for the pictures and the pointers.

Smooth Sailing

regards charlie

[wes]

Charlie - good point about painting the shaft. Since I'm 140 miles from the boat I figured I'd go ahead and run the paint up the shaft. Not hard to clean it off if it causes binding. Will let you know!

Wes