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Wooden Rudder repair


bodega87

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I have some cracks in the wooden rudder. Previous owner "repaired" by filling with plumbers putty and painting over. I'd like to do something a bit more secure. I've acquired some CPES and filler from http://www.smithandcompany.org/CPES/ 

Plan is to sand her down, coat with the cpes, filler and coat again before painting. Any snafus in my plan? There is strangely not a lot of information specific to wood rudder repair online. 

IMG_3112.jpg

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Aren't there Ensign  forums of some sort? ??  They have wood rudders 

 

Anyway... I don’t know the construction of that rudder but my guess is the cracks are between the boards. When the boat is out of the water the boards shrink. 

Before launching, you shove the boards together and they swell up again while soaking 

filling the cracks with plastic screws up the wood 

mostly??  The rudder in the photo looks fine. 

I would add a coat of paint, splash the boat and spend my time riding around relaxing 

 

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Yes, I'm hesitant to comment as I can't see much about how the rudder is made structurally. But the fundamental thing to keep in mind is that wood moves with changes in moisture, it has to move or something will break. That's why wooden planked boats are not caulked with rigid materials like epoxy. IF the gaps are where the rudder's planks need to expand you may be forcing structural breakage by blocking that expansion.

Trying to keep water out of wood with coatings is generally a futile endeavor, particularly with old construction. 

 

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Typical construction of wood rudders on early glass boats had long bolts through the rudder stock and the wood parts.  A crack in the wood parts is of small consequence.              Paint it and go sailing.

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Same thing happens in wide-plank wood floors. They get put in all tight & snug in the humid summertime, and then dry out & shrink when the house gets heated and dry in the winter.  (AC can dry out boards by reducing the humidity too.) This leaves gaps between the boards, which is why wood flooring is usually tongue & groove or shiplap. Dirt & grit gets in between the boards when they're dry.  Then when the boards swell again in humid conditions, the crud between them ends up crushing the edges of the boards. If you put hard stuff like epoxy in the cracks, the expanding wood could pull the nails out because there would be no where for it to go. Planked boats that have their  seams packed too hard with caulking can sometimes pop planks because of this. Or the over-caulked seam can crush the edges of the planks when they swell up, making the gap problem worse. .

 

It might be worthwhile to try wetting your rudder with a hose over the period of several days or a week and see what happens to the cracks. They may disappear.    

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The rudder is not planked. It appears to be one piece hence my concern. There will obviously be swelling once it takes back some moisture, but I do worry about strength. The clear penetrating epoxy is meant to soak into the woods natural fibers and allow for natural flexing. I provided a link hoping someone would click it. It is not the same thing as slapping a coat of west systems onto it. 

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Surprised if it is actually one piece, but even if it is, there should still be drifts to help keep it together and straight.  A single piece would tend to warp, so even a single-plank rudder should have drifts to help keep it from warping.  Thus no reason to be overly concerned about it or to take extreme measures to "fix" it. Wooden rudders are often pieced together so the annular rings in adjacent planks go in opposing directions - so their warping essentially cancels each other out. ( Chapelle's "Boatbuilding" , W.W. Norton, NYC 1969 pp 160-165) They're then drifted together tightly.  

If you keep the rudder wet for a week and the cracks don't close up, you can certainly go ahead with the epoxy treatment.  The worst that could happen would be for the rudder to blow apart because of the wood expanding against the hard epoxy wedges that you created in the cracks.  Then you can build a new rudder. 

I did click on the link. Sounds like "git-rot". If you create an impermeable epoxy barrier on the outside of part of the rudder, moisture inside the rudder will be blocked there and will fester.  Another recipe for building a new rudder after it rots to pieces. 

 

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40 minutes ago, PaulK said:

Surprised if it is actually one piece, but even if it is, there should still be drifts to help keep it together and straight.  A single piece would tend to warp, so even a single-plank rudder should have drifts to help keep it from warping.  Thus no reason to be overly concerned about it or to take extreme measures to "fix" it. Wooden rudders are often pieced together so the annular rings in adjacent planks go in opposing directions - so their warping essentially cancels each other out. ( Chapelle's "Boatbuilding" , W.W. Norton, NYC 1969 pp 160-165) They're then drifted together tightly.  

If you keep the rudder wet for a week and the cracks don't close up, you can certainly go ahead with the epoxy treatment.  The worst that could happen would be for the rudder to blow apart because of the wood expanding against the hard epoxy wedges that you created in the cracks.  Then you can build a new rudder. 

I did click on the link. Sounds like "git-rot". If you create an impermeable epoxy barrier on the outside of part of the rudder, moisture inside the rudder will be blocked there and will fester.  Another recipe for building a new rudder after it rots to pieces. 

 

Indeed. There seems to be be two schools of thought with wood rudder repairs. Leave it alone, or glass it over. Glassing seems excessive and prone to a lot of error, no need to get ind depth here but theres a lot of room for mistakes. Leaving as is, with cracks that go through to the other side seems a bit dodgy too. I was hoping that this material which is a LOT like git rot, plus filler would be able to take up some of the gaps here without causing a catastrophic rudder "blow up".  Some of the gaps are large enough that I don't think it possible for the wood to swell up enough, but I reckon thats not a huge issue at the end of the day. At the end of the day the name of the game is avoiding a total failure, and throwing any kind of expoxy in there seems like it will create more potential for this than leaving as is. 

While this still leaves the overall question unanswered, I suppose its good enough for me to leave as is this season and see wtf happens. Thanks all around. 

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Without knowing the construction of the rudder it's alot of guess work.  You might post on the wooden boat forum for some better feedback.  Checks in a solid wood rudder IE solid sections connected with bolts or drifts would not be anything to worry about.  I would mostly be concerned with rot.  Strip all the paint off and see what you are dealing with.  If it's sold wood keep it wet with burlap and spray down. No rot and only small checks fill with underwater seam compound and repaint.  If it has rot soft spots etc than that's a whole different story. There is a army of people to help you on wbf...

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