Rebuilding a rudder

owen

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I am pretty sure at least one of the two tangs on my rudder has come adrift.The rudder is foam filed fibreglass with stainless stock
i am told the tangs are glassed on to one side of the rudder and the other side was attached and then it was filled.

It seems the way to go is cut a large hole in the unglassed side , dig out foam and get tang rewelded/replaced

I wonder if anyone else has done similar work and would offer any advice .
 

ghostlymoron

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I've read that the way to do it on a Leisure rudder is to slit it all round, separate the two halves, remove any foam fill, repair tangs then rebuild. Never actually done it though.
 

pandroid

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I had mine split and rebuilt by the builder (Jeremy Rogers) and I've also seen one done (on a different boat) in Germany. In both cases they had to destroy the rudder to split it and had to rebuild/remould it.

In my case the stainless was OK, but the foam was breaking down making me think something was adrift.
 

ballyabroad

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What boat seems to have the rudder issue?

On Sabre 27's it not unheard of for the Tangs to come adrift, especially as some were made using a combination of stainless and mild steel. I had the boatyard do mine. Pretty straightforward, split the rudder around the seam, scrape out the foam, allowing to dry. Make good any issues with the tangs (mine had two re-welded). Epoxy back together and fill with foam again. On some boats not a big job - mine was around £300.00. Others such as Mads above with are a bit of a nightmare.
 

Quandary

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I did it on a friends Westerly which had come off its mooring. I cut off one side, dug out the foam on that side and moulded a new side and extended the bottom part which had broken off. The job was done indoors because of winter temperatures, part of it in our kitchen. Materials included thin rigid closed cell foam sheets (about 8mm.) which I laminated together to form the new plug, epoxy resin, powder bound mat and woven rovings. It took a few weeks of my spare time but I was helped in that, surprisingly, the tang welds were intact, just bent a little. I tried to ensure that there were strong grp webs joining both sides to the tangs and to each other. I found a Black and Decker Workmate made a good work bench as I could work on it flat or inverted with the rudder shaft down through the slot. Putting it together I made some ply templates of the profile at various points but focussed mainly on strength then built it up and faired it with a mixture of resin and micro bubbles before coating with epoxy resin and primer. I had a whole winter so did not rush it but probably worked for about 40 - 50 hours.
The materials all came from CFC and cost just over £100 which the owner paid, though I must have over estimated because I had some foam sheets and mat left at the end. I already had the epoxy coatings I used to finish it. I built it one side at a time with the second side moulded on top of the foam core and bonded to the first. It is possible to mould the two sides separately and bond them together but I decided that the other way ensured a stronger and more watertight bond though it involved a bit more fairing. I did not use any form of liquid foam, the closed cell rigid sheets which formed the core were easier to shape. I suspect the rudder gained a few pounds in weight.
My previous grp moulding experience was making skinny tanks for 'grass track' motor bikes that I used to race and a new bum on a frog eye Sprite but that was long long ago in my careless youth when polyester resin was the only diy choice. It is not a particulary difficult task and there are plenty of books on technique and materials. I used epoxy resin with the appropriate mat rather than polyester which perhaps might have been a bit easier with a bit less risk if temperatures are adverse. It took longer because I was not in a hurry and avoided really cold spells,
 
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Joker

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I had a rudder rebuilt in Southampton. The new stock was a section of stainless steel pipe, which they welded to a thinner stainless steel bar, and then put foam around and then the original rudder skin.
Unfortunately, when I was sailing down the coast of Latvia, my new expensive rebuilt rudder failed. It folded up through 90°. I had to anchor in 17 m of water and wait for rescue by the Latvian Navy.
It turned out the weld between the pipe and the bar had corroded and failed. Luckily for the people in Southampton, the insurance company paid up, so I was not out of pocket.
I know this anecdote bears little relationship to your problem, but I thought I would relate it all the same.
 

Quandary

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BTW - I only got away with using the kitchen as a workshop because at the time I was refitting it and the cupds. and work tops were temporary, in winter you need a workshop with space and heat to use epoxy.
 

owen

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I have just opened the rudder and surprisingly there are no tangs . In fact there is no shaft within the rudder. The squared off shaft enters the top of the rudder and then there appears to be a glassed in flange inside the top of the rudder connected to the shaft.It all appears tight and rigid.So I cannot work out where the movement is coming from.
I am amazed that the rudder shaft does not extend down the shaft but presumably the mechanics have been worked out and the flange is enough
 
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