CONTESSA 32 ASSOCIATION Homepage
Forum Home Forum Home > Technical Help > Engine, Gearbox, Stern Gear, etc
  New Posts New Posts RSS Feed: Cracks in rudder spine and possible disalignment
  FAQ FAQ  Forum Search   Calendar   Register Register  Login Login

Cracks in rudder spine and possible disalignment

 Post Reply Post Reply Page  12>
Author
Message
blueheron View Drop Down
CO32 Members
CO32 Members
Avatar

Joined: 15 Jul 2009
Location: Skye
Online Status: Offline
Posts: 5
Post Options Post Options   Quote blueheron Quote  Post ReplyReply Direct Link To This Post Topic: Cracks in rudder spine and possible disalignment
    Posted: 18 Mar 2016 at 1:36am
Hi co32 members, I hope you can help us.

I have some severe issues with the rudder on CO32 Blue Heron (1971)

- I get less stbd turn than port.
- There are cracks running vertical from top and bottom in the neck of the rudder.

Attached some photos, as you can see the big crack although at centre is much more visible when rudder is steering to port  - explains on thing!

Whilst removing the skeg cap and the 3 machine screws, I found the aftmost screw to be almost corroded away just behind the screw-head. None of the screws were very tight, I could almost open them with my fingernail. The centre screw was actually a (thicker) bolt and this was a bit tighter. Were they fitted like that? (1971) Or perhaps this indicates this is not the first rudder removal for this boat? (we adopted her in 2009)

Any repair advice appreciated - alas a budget is not existent so a new rudder is not an option this year.

Alan
Blue Heron


upper crack
UPPER CRACK - VIEW FROM STBD




LOWER CRACK - view from STBD


steer portside
UPPER CRACK  - VIEW FROM PORTSIDE


Back to Top
blueheron View Drop Down
CO32 Members
CO32 Members
Avatar

Joined: 15 Jul 2009
Location: Skye
Online Status: Offline
Posts: 5
Post Options Post Options   Quote blueheron Quote  Post ReplyReply Direct Link To This Post Posted: 18 Mar 2016 at 10:42am
Also Having difficulty releasing the rudder stock from the shaft. I have tried as suggested by the Technical paper CO32 rudder removal (by levering  the block up and bashing it) but to no avail.
Also tried some pressure down on the stock (centre) with a gear puller braced on the external stainless steel block - but not sure there is something else preventing release so scared to really apply it hard.

There is a rectangular hole as you see from the top - no grub screw in there as far as I can find... Any ideas?

upper view
top view


rear view of block - no grubs
no grubs I can see


side view - no grubs

side view no grubs I can find


Back to Top
George Isted View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 08 May 2009
Location: Solent
Online Status: Offline
Posts: 374
Post Options Post Options   Quote George Isted Quote  Post ReplyReply Direct Link To This Post Posted: 18 Mar 2016 at 1:58pm
Not seen a Co32 tiller block on the top of the rudder stock like that before, normally it's a solid bronze block but as your boat is an early boat it's possible that was fitted from new (although looks like it has had a repair or two).

That rudder has seen better days. If you can't replace it I'm sure that with care it can be repaired. Once off you will need to grind out that crack so that there is plenty of surface area each side to bond too then rebuild with resin and glass matt. It's very likely that the rudder will have some water in it so I suggest you drill a couple of holes to let that drain before re-sealing.

You may not wish to hear it but I would be very tempted to get a new rudder.

Have you tried a hub puller to remove the tiller block from the stock? Or you can (with the heel fitting removed and the rudder loosely supported) put a suitable sized socket on the top of the stock and hit it with a lump hammer. I normally do the latter and a couple of healthy taps will separate the two.
George Isted
www.solentboatbutler.co.uk
Contessa 32 "Concerto"
Co32 Class Measurer and ex Class Captain.
Back to Top
George Isted View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 08 May 2009
Location: Solent
Online Status: Offline
Posts: 374
Post Options Post Options   Quote George Isted Quote  Post ReplyReply Direct Link To This Post Posted: 18 Mar 2016 at 2:00pm
Looks to me as though there are a couple of hairline cracks in the rudder block (STBD side), I suggest you inspect and repair/replace if necessary.
George Isted
www.solentboatbutler.co.uk
Contessa 32 "Concerto"
Co32 Class Measurer and ex Class Captain.
Back to Top
Richard Ritchie View Drop Down
CO32 Members
CO32 Members


Joined: 13 Jul 2009
Location: Winchester
Online Status: Offline
Posts: 69
Post Options Post Options   Quote Richard Ritchie Quote  Post ReplyReply Direct Link To This Post Posted: 18 Mar 2016 at 9:20pm
Note that there is a key in the "square hole" that you describe.
This is a safety device: the torque is taken on the cone fitting of the rudder head.  Make sure this is well seating when you replace.
The key will normally need to go back the same way round.  It tends to have taken up the shape.... 
At the heel plate: originally the machine screws went into fibreglass, and tend to work loose.  Many people have put in a tapped steel  plate when refurbishing.
Note that the rudder hangs from the top: the heel plate is there for sideways forces only.
(Mine is in pieces at present, but in order to replace prop shaft, not rudder.)
Good luck
Richard
Richard Ritchie
Badger of Baltimore
IRL 120
Back to Top
doug View Drop Down
CO32 Members
CO32 Members


Joined: 05 Aug 2009
Location: Plymouth
Online Status: Offline
Posts: 88
Post Options Post Options   Quote doug Quote  Post ReplyReply Direct Link To This Post Posted: 20 Mar 2016 at 11:06am
Hello Blueheron,

I am sure you could resurrect the rudder for not much money but a fair deal of effort. It gets easier once you have the rudder off and on the bench. I agree with the others generally and feel that you should open the rudder right up and inspect the internal welded tangs while you are at it - there is a paper by JR on the subject, I think - check on the home page. This would help you in making a more complete repair.

The heel plate could be opened up for larger set screws and the holes in the skeg re-drilled and tapped - any damage would need to be made good first.

I also agree that the top block looks suspect, is it stainless steel? There is good reason for the bronze block normally fitted in that steel on steel can gall together and be almost impossible to remove, even with an hydraulic puller. If this is the case I would cut if off and replace with the standard item, it would be expensive but I really would do it.   If the taper has been tampered with, a local engineering firm could make a block to suit.    Best of luck with the job.
Back to Top
blueheron View Drop Down
CO32 Members
CO32 Members
Avatar

Joined: 15 Jul 2009
Location: Skye
Online Status: Offline
Posts: 5
Post Options Post Options   Quote blueheron Quote  Post ReplyReply Direct Link To This Post Posted: 21 Mar 2016 at 1:58pm
@doug top block is stainless yes - but there appears to be no "key" in the rectangular hole - it appears to be quite empty. will try to get some light in there and see if it has dropped or perhaps corroded away.

thanks all for your helpful responses!
Back to Top
waratah912 View Drop Down
CO32 Members
CO32 Members


Joined: 17 Dec 2010
Location: Lymington
Online Status: Offline
Posts: 98
Post Options Post Options   Quote waratah912 Quote  Post ReplyReply Direct Link To This Post Posted: 25 Mar 2016 at 10:20pm
Try giving it a daily dose of plus gas for a couple of weeks, then refit the bolt so that it is just clear of the stainless fitting, heat it as hot as you can get it without damaging the surrounding cockpit sides / floor, use heat proof tiles or similar for protection. Fit the puller and do it up a tight as you can, then hit the end hard with a heavy hammer. the shaft should then drop by however much clearance you originally left between the bolt and the stainless fitting. Be brave, because the alternatives are worse.
If that doesn't work, you're in to cutting it off, which is going to be a bitch. I'd start by taking an angle grinder to the fitting down the keyway - less chance of damaging the shaft, less steel to cut and accessible. You're not going to be able to go all the way down, but you might get enough that a cold chisel driven into the top of the gap would open the fitting on the taper enough to break the stiction. 
Paul Smith
Waratah
Contact details available from the members only area
Back to Top
Keny View Drop Down
CO32 Members
CO32 Members


Joined: 29 Aug 2010
Online Status: Offline
Posts: 75
Post Options Post Options   Quote Keny Quote  Post ReplyReply Direct Link To This Post Posted: 28 Mar 2016 at 11:51am
Just to add to above . Try cutting through the vertical welding with a thin s/s disc. If you can separate the outer casing everything else will be a lot easier. Also tapers are often successfully removed by hitting them sideways with a backing weight of some sort.
keny

Back to Top
blueheron View Drop Down
CO32 Members
CO32 Members
Avatar

Joined: 15 Jul 2009
Location: Skye
Online Status: Offline
Posts: 5
Post Options Post Options   Quote blueheron Quote  Post ReplyReply Direct Link To This Post Posted: 08 May 2016 at 11:16am
Okay, so just to update...

After three efforts at heating & 'persuading', she eventually dropped... Yeh!

Thanks for all your comments...

Now it's time to cut the rudder in half...

As per:

http://contessa.simdif.com/exterior.html
&
http://therebepirates.com/2010/12/02/maintenance-is-expensive-crevice-corrosion-in-the-rudder-stock/

Wish me luck!

If anyone's done this before, any detailed log of the experience...?
Back to Top
 Post Reply Post Reply Page  12>

Forum Jump Forum Permissions View Drop Down