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Adastra

Rudder Stock Bent

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Hello All! 

So our Martin 32 Rudder has been zipped open and is 3 pieces and the rudder stock has been exposed. It luckily the rudder stock and blades are not corroded but the foam core is a write-off.

One thing we have noticed is that the rudder stock is slightly bent. We are thinking of bending it back. Looking for any advice. 

The bend is not that obvious so we're wondering that if we've already zipped the rudder open and planning on putting it back together, if it would fine to just put it back. 

Another consideration I have been milling on is that the top of the rudder has been repaired in the past from rubbing up against the bottom of the hull/transom next to the rudder stock. There's currently the same damage on the other side. I'm not sure if the bent rudder stock would make it better or worse. So I'm considering if a solution would be to repair and maybe sand down the area that's coming into contact with the hull and then limiting the range of the rudder by limiting the range the tiller can be manipulated on the deck.

Also thinking it would be smart to do a spot repair on the area of the hull that had been rubbing though it appears to be minimal. I have not done any repairs below the waterline but experienced in doing epoxy and gelcoat repairs above the waterline. Any proceedural advice would be greatly appreciated.

:) 

A.

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Is the stock solid? If so, I'd think about heat bending it like you do with prop shafts. Possibly easier to do for an amateur.

You might also talk to to Ross Dafoe at VM Dafoe. Super experienced guy. They are the local best supplier of s.s. shaft material. It might be simpler (faster) to just buy a new length of shafting and maybe have them machine a square head for a tiller and then reweld the blades onto the new shaft. You might consider a higher strength/more corrosion resistant material https://vmdafoe.com/shafts/

They may offer straightening services too.

Cold straightening:  http://www.gard.no/web/updates/content/1342889/hull-and-machinery-cold-straightening-of-bent-shafts

For the hull rubbing is it into the glass much? If "minimal" i.e. just scuffed up gelcoat just paint and forget.

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If the rudder post bent athwartship or fore and aft? If it's bent athwartship you definitely have a problem. Trying to straighten it may fatigue the metal and lead to a full break.

If fore-n-aft, where is the rudder stock bent? A or B. If it's 'A', that's intentional. If it's 'B', that's pretty unlikely but treat it the same as an athwartship bend.

rudder_post_bent.png.95742f09d2a3c5d023a823f1d6870d71.png

In any event, if you get a new rudder built, they will use new metal.

 

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A local metal shop could straighten it eight out. I had a Catalina 42 rudder repaired a few years back.

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You really shouldn't attempt to straighten a bent tube.  Therein lies lurking failure.  You can take the bend out of the metal (maybe), but you can't take out the stress lines that formed during the bending.  

Tubes are cheap, welding is cheap.  Bent rudders are annoying and potentially very expensive.  

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Not trying to be cute, but what is your deductible?

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19 hours ago, Zonker said:

Is the stock solid? If so, I'd think about heat bending it like you do with prop shafts. Possibly easier to do for an amateur.

You might also talk to to Ross Dafoe at VM Dafoe. Super experienced guy. They are the local best supplier of s.s. shaft material. It might be simpler (faster) to just buy a new length of shafting and maybe have them machine a square head for a tiller and then reweld the blades onto the new shaft. You might consider a higher strength/more corrosion resistant material https://vmdafoe.com/shafts/

They may offer straightening services too.

Cold straightening:  http://www.gard.no/web/updates/content/1342889/hull-and-machinery-cold-straightening-of-bent-shafts

For the hull rubbing is it into the glass much? If "minimal" i.e. just scuffed up gelcoat just paint and forget.

Since you've been sorta following since the first post, we're trying not to buy a whole new rudder (yet). I think if we were to get a whole new stock, we would likely consider getting a whole new rudder. In all honesty, I know having a new rudder made would be slick because rudder technology has improved a lot in the last 40-50 years. If we were to go that direction, we would likely slap together the old rudder and save up for a new one the following season. What we don't want to do is have her sitting on the hard for another month and ideally want to start enjoying her on the water asap. All things considered, there's a lot of things we can do maintenance wise while she's on the water, but obviously to sort out the rudder, we pulled her out. 

We weren't planning for Covid when we started this process, and to be prudent with our time and money, we are doing pretty much everything ourselves so we can put more bang into the boat for our buck. If our fresh food supply is interrupted this summer from the pandemic, I'm gunna want to be on the boat fishing and crabbing with a beer in my hand - if you know what I mean.

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Then just leave the stock alone and stick a new blade around it. Go Boating. Catch fish. Drink beer. Save for a complete new rudder.

Job done.

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Putting a new stock with a welded web in an existing shell isn't hard.  I've done it on a sawhorse table in a boat yard.  

If the original rudder is at all an OK basic shape then you can fair it out to a decent NACA profile pretty easily.  You can get those on line and then cut templates to fit on your shell.   Busy work project for these times.  

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23 hours ago, Somebody Else said:

Trying to straighten it may fatigue the metal and lead to a full break.

 

Fatigue is "loss of strength due to repeated load cyclings. 1 bend back isn't the end of the world. I would be very wary of doing it on pipe or thick walled tube however; too easy to kink the wall. Solid shafts are much safer.

If it's rubbing on the hull I don't think the bend is a deliberate one inside the rudder :) 

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I've bent a few rudders back in line - like someone already suggested get a machine shop with a press and they should be able to straighten it out.

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