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rudder collar repair

Posted: Mon Jan 13, 2020 6:52 pm
by rickrohrer
Hi all,

Looking for some insight re the urgency of repair for a cracked rudder collar.

The rudder was last serviced and the bearing inspected in the '16 - '17 off-season. This was done at an excellent shop (IMC in Bristol, RI), and all was well. When the boat was hauled this past fall, though, I noticed that fore and aft sections of the rudder collar had broken away (pics). The rudder had functioned well all season, including during a trip to Bermuda and back. No leakage, no play.

For me boat maintenance is a solitary affair, and I know that dropping the rudder is a 2-man job. Unfortunately I don't feel I can trust the boat yard where I am now to take care of this. In mid-season 2020 I was hoping to sail to a better yard up the bay (in Marion, MA) and have them fix it. What I don't know is just how safe this plan would be - I'd like to avoid a nasty failure!

Appreciate any advice -

Rick Rohrer
Rocinante, J/109 #146

Re: rudder collar repair

Posted: Mon Jan 13, 2020 7:00 pm
by rickrohrer
Pics didn't load with the original post - here they are -

Rick

Re: rudder collar repair

Posted: Sat Jan 18, 2020 9:36 am
by jrlivingston
There are a lot of experts on this forum - and I am sure they will weigh in. But I would not go anywhere with the collar looking like that. I would worry about too much potential movement of the rudder post that may cause damage to other parts of the rudder system.

Re: rudder collar repair

Posted: Sat Jan 18, 2020 5:06 pm
by rickrohrer
Thanks for the reply. The collar itself is so thin that I was having trouble visualizing it as a structural element, vs just a surface for minimizing turbulence around the rudder.

Very awkward to discover something like this after hauling at a yard not prepared to deal with it!

Rick

Re: rudder collar repair

Posted: Sat Jan 18, 2020 5:18 pm
by Vento Solare
The only way that collar can deform / crack is if there is movement in the lower bearing putting stress on the collar. I would check that first with a simple aggressive push / pull on the rudder while you look for any movement. If the collar is too tight and the deflection is minimal, you might try sanding a few thousands of an inch around the outer radius of the collar to allow some motion, but not allow deformation of the collar.

The collar doesn't have any structural purpose as you note, it's just to stop water flow. The area is flooded around the bearing, so extra clearance around the collar won't hurt.

If the rudder push / pull shows movement, you should have George Borges take a look and see if he needs to fix it right.

Re: rudder collar repair

Posted: Sun Jan 19, 2020 1:08 pm
by rickrohrer
Thank you Bill. There was no play to speak of when I tested it after hauling, but I'll go an wail away at it again to verify

If still normal, how should the space between the outer surface of the bearing and the hull be filled? In another thread you included a pic of the rudder re-install on Vento Solare (reproduced here without your permission!) which shows that space, but no mention of how you managed it. Fairing compound + putty knife?

Rick

Re: rudder collar repair

Posted: Fri May 22, 2020 5:03 pm
by rickrohrer
Just a follow-up note of resolution:

In effecting a temporary repair I got up close, and discovered to my surprise that there was a ridge of barnacles on the very top of the rudder, in the centerline, on the parts both fore and aft of the shaft! It was not visible to a 5' 11" guy standing beside the rudder. The missing pieces of the plastic ring corresponded exactly to the port-stbd swing of this ridge, and I'm quite sure it was simply abraded away.

The temporary repair was simply to spray a small amount of polyurethane foam into the the depths (alongside the outer surface of the bearing), trim it, and apply fairing compound

Next time the rudder is dropped I'll get a proper repair

Thanks again to Bill K for the suggestion

Rick