CONTESSA 32 ASSOCIATION Homepage
Forum Home Forum Home > Technical Help > Engine, Gearbox, Stern Gear, etc
  New Posts New Posts RSS Feed: Rudder bottom bracket screws loose
  FAQ FAQ  Forum Search   Calendar   Register Register  Login Login

Rudder bottom bracket screws loose

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


Joined: 18 Jul 2009
Location: Chatham - B29
Online Status: Offline
Posts: 51
Post Options Post Options   Quote GlennG Quote  Post ReplyReply Direct Link To This Post Topic: Rudder bottom bracket screws loose
    Posted: 09 Apr 2012 at 12:16am
When I lifted Perle this year the bottom rudder bracket (is it called a 'pintile'?) was loose.  I chopped off the skeg foot and found that the aft-most screw was loose and has no 'grip' in the GRP,  e.g. it keeps turning when you screw it in.

What's the consensus for fixing this?

I hear that there's little hard resin to drill a significantly deeper hole.  An engineer has suggested drilling a 1" hole transversely through the skeg and inserting a 1" rod that's been drilled and tapped to take the pintile screw. Sounds OK to me and would permanently solve the problem.  Opinions? 
Back to Top
Simon Begley View Drop Down
CO32 Members
CO32 Members


Joined: 03 Nov 2010
Online Status: Offline
Posts: 28
Post Options Post Options   Quote Simon Begley Quote  Post ReplyReply Direct Link To This Post Posted: 09 Apr 2012 at 7:32pm
When we replaced Blue Jalma's rudder we also replaced the bottom bracket. The old one was rather worn and had suffered some galvanic corrosion. The holes in the new bracket didn't match the old ones. JR advised filling the holes with a hard epoxy filler and drilling and tapping new holes into this. Two years later everything is still solid. 
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: 09 Apr 2012 at 10:27pm
We had a similar problem with Waratah about 10 years ago. All the screw holes were filled with Epoxy and then re-drilled and tapped. Screws refitted with loctite and no problems so far.
If you've got the rudder out, consider replacing the rudder bearings too.
 
Back to Top
GlennG View Drop Down
CO32 Members
CO32 Members


Joined: 18 Jul 2009
Location: Chatham - B29
Online Status: Offline
Posts: 51
Post Options Post Options   Quote GlennG Quote  Post ReplyReply Direct Link To This Post Posted: 10 Apr 2012 at 9:36am
Such a pity that you can't turn the boat over so you can pour in the epoxy:-)

The bracket and rudder appear to be in good condition as are the screws.  The main issue is the aft-most screw -- which takes all the load -- being loose.  I do wonder if filling, drilling and tapping it will work adequately as re-tapping will remove pretty much all of the new epoxy.

I do quite like the idea of inserting a drilled and tapped bar transversely through the skeg.  Then I know that the thing won't work free as the load is spread across a large area.  Has anyone had any experience of this?

Regarding the rudder bearings;  isn't this an awfully difficult job to press out the old bearings?  Not least accessing the cavity.
Back to Top
George Isted View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 08 May 2009
Location: Solent
Online Status: Offline
Posts: 371
Post Options Post Options   Quote George Isted Quote  Post ReplyReply Direct Link To This Post Posted: 10 Apr 2012 at 10:11am

Here is another idea that would be worth considering, I have done this elsewhere on the boat.

 

Get a pair of nuts for the machine screw, drill out the hole in the skeg so that it is big enough to accept the full length and width of the maching screw AND nuts.   Epoxy the nuts and machine screw in place having applied a SMALL AMOUNT of Vaseline (or grease/release agent) to the screw threads only.  Once set you can remove the machine screw and you are ready to go – no cutting of threads into GRP required.

 

Hope the above makes sense.

George Isted
Contessa 32 "Concerto"
Co32 Class Captain and Measurer.
Back to Top
GlennG View Drop Down
CO32 Members
CO32 Members


Joined: 18 Jul 2009
Location: Chatham - B29
Online Status: Offline
Posts: 51
Post Options Post Options   Quote GlennG Quote  Post ReplyReply Direct Link To This Post Posted: 11 Apr 2012 at 10:04pm
That's a good idea.  It could be further re-enforced by drilling diagonally and inserting screws set in epoxy.

Looking at the bracket,  the aft-most screw will take a real pounding from the constant sideways forces whilst helming and (considerable) weight of the rudder.  I'm surprised that this bolt isn't much longer.
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: 12 Apr 2012 at 10:29pm
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: 12 Apr 2012 at 10:43pm
No need to turn the boat upside down, mix the epoxy with Microfibres to a consistency like peanut butter and it stays put. Isn't the weight of the rudder is taken on the top bearing rather than the heel fitting?
Also consider using a stainless helix insert which will bite deeper than a normal machine screw, but is threaded internally to accept a machine screw. for example http://www.wti-fasteners.co.uk/ This requires a smaller hole than drilling out to accept a nut and provides a longer threaded length.
As regards rudder bearings, the old ones are plastic so can be cut (judicously!) with a hacksaw blade to release them. Fitting the new bronze ones is rather more fun - definitely a tight fit and consequently no downward load on the heel!!
Back to Top
GlennG View Drop Down
CO32 Members
CO32 Members


Joined: 18 Jul 2009
Location: Chatham - B29
Online Status: Offline
Posts: 51
Post Options Post Options   Quote GlennG Quote  Post ReplyReply Direct Link To This Post Posted: 03 May 2012 at 6:00am
The engineer who's done the work to replace the prop shaft, install a PSS and cutlass bearing said that one reason for the pintile bearing becoming loose was because of the additional weight placed upon it because the spacer/washer above the top bearing has worn.  He's fitted another spacer which has lifted the rudder up a little,  thus reducing the weight on the pintile.

Seems logical.  Anyone else found this?
Back to Top
St Paddy View Drop Down
CO32 Members
CO32 Members
Avatar

Joined: 10 Feb 2010
Location: Swanwick
Online Status: Offline
Posts: 94
Post Options Post Options   Quote St Paddy Quote  Post ReplyReply Direct Link To This Post Posted: 08 May 2012 at 8:06am
 

You will have a job to keep the epoxy in, the hole will be wet and drity. If your heel plate is standard it will be held by 5/16 whit. counter sunk screws.

I would retap the holes if it were mine or a customers boat.
 
Your next size up from that is M10 with a tapping drill of 8.5mm (5/16 is 8mm) so you can clean out your worn hold and re-tap. You could go 3/8th UNC
 
you need the heel plate holes opened out

 I would use 316 socket Cap heads. GTC fixings will post them to you google them, no min order. The chandlery will only have 405 stainless, that will only last a few years in the heel plate. when done post the tools back.

Use acetone to clean and sikaflex when you assemble, the side load on the heel plate skids the fitting side to side and that is why the screws and threads fail. If that happens you have a blade rudder with a 1 1/4 shaft.

Back to Top
 Post Reply Post Reply Page  12>

Forum Jump Forum Permissions View Drop Down