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TQA

Rudder thrust washer[s] location construction and material

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I have a 44 ft GRP monohull [ Explorer 44 ] which was built in the USA in 1978 by the New Bombay Trading Company It has a skeg hung rudder. The rudder shaft enters the hull just above the waterline at rest. The boat is wheel steered with a mechanical [ wire ] system. 

i am pretty sure the rudder has dropped a little maybe an 1/8 th in the last year. So I suspect that something is up with the thrust washer. 

What sort of thrust washer is it likely to be and where will it be located. My engineering common sense says it will be at the top of the rudder tube where it comes through the hull and under the collar that prevents the rudder moving down. At least that is my assumption and we all know how dangerous they can be. 

Material Tufnol ? Gunmetal ? Delrin ?

If it was tufnol can I use delrin as a replacement?
 

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I'm right in the middle of the same thing and I used UHMWPE. Simply made a doubled hole saw to get the correct I.D and O.D in one pass for the ring and cut it from a piece I had on hand. My rudder had dropped a lot more than 1/8" though - more like 1 1/2".

It's been too cold to test fit it but maybe tomorrow.

Take a look at the Mo Bettah Too thread below in this forum for comments and input on the various possible materials.

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I've also seen a rudder where there was a transverse pin through the stock, at the deck bearing to keep the rudder from falling out.

Delrin (Acetal or Polyoxymethylene is generic term) is a first choice but costly & probably hard to find if you are still in the Caribbean. 

UHMW wouldn't be bad depending on the collar. It will slowly creep under high loads but the weight of a rudder ain't "high load"

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On 12/6/2018 at 6:31 PM, SloopJonB said:

I  Simply made a doubled hole saw to get the correct I.D and O.D in one pass for the ring and cut it from a piece I had on hand.

 

holy crap, never thought about doing that...  thanks..

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Read the details I posted in the Mo Bettah thread - the stuff is hard to cut.

Saying "one pass" is a little misleading - probably more like a dozen passes due to the way it heats everything up.

"One machine setup" would better describe it.

For the last one I cut I had learned to take little bites - run the doubled saw down, let it brush the bottom, pull it out, blow everything clear, do it again...and again....and again......

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On 12/7/2018 at 1:37 PM, Zonker said:

I've also seen a rudder where there was a transverse pin through the stock, at the deck bearing to keep the rudder from falling out.

That's how mine is hung. The clearance needed to install that roll pin required a second, split collar that could be installed after the rudder head was pinned to the stock.

Rudder Head.JPG

Rudder Shaft.JPG

Rudder Head Mounted.JPG

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SloopJonB oh how I wish I had access like that. Who ever works on my rudder will be small and flexible as the access is going to be challenging'.

As for making a new thrust bearing I am hoping it will be something I can replace WITH DELRIN.

I will have a big piece and have access to a lathe. Delrin turns nicely. 

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I hear you - access to everything is one of my top priorities now when considering a boat. The only access problem on my current boat is the stuffing box because it's on a V-Drive.

I'll be getting a man in when it requires adjusting. :D

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Got a trained kid?

Got a friend with a kid?

Know any small asian guys? (no, not a racist but asians tend to be smaller than white folks and shipyards tend to always have a small asian guy who gets stuck in the smallest tanks to weld or paint)

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Hmm reminds of the days when I sold British Leyland cars. We always had a small and flexible apprentice. He would be folded into the boot with a torch, rubber mallet and the lid down. Someone would spray water onto the lid and the apprentice would hammer onto the lips of the boot to try and stop the leaks. 

Sometimes we just had to give up, drill a hole at the low point, fit a thru grommet and call it good.

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A grommet in a British car?

Now there was a custom installation. How did you ensure the wiring would continue to chafe through?

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