Rudder Surgery Part 4

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Rudder Surgery Part 4

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Iain C
United Kingdom
181 Posts

Posted - 22/01/2012 : 18:38:14
Nearly there now! Quick update for you...

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So in this shot the rudder halves are glued back together, with the clamps (lots!) removed. It certainly took a lot of bog! Oh, and before you do this, you'll need to measure your tang "ramps" and approximate internal volume for mixing up the foam filler!

Initially, I laminated all round with 45/45 biaxial. However, I was not happy with the result for two reasons. One, the biaxial is not that pliable and was not easily persuaded to go around the tight trailing edge radius, even with the aid of the vacuum pump. Secondly, this batch of epoxy did not cure properly. When I investigated it, I came to the conclusion that in my dimly lit shed I'd grabbed a pot contaminated with either water or acetone when I mixed it. So it came off (very easily!) and I re-did it with tape and weave and got a much better result.



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Next job was this little contingency plan. In the event of tiller/joint failure (I hope I've ruled out tang failure!) I now have this piece of 32mm carbon fibre tube in the top of the rudder...big enough to get a line through from each side with a figure of eight in, and up to the winches so I have some rudimentary emergency steering. The tube is completely epoxied into the bog joining the 2 halves...I'd be hesitant to do this modification if your bogged section is smaller.


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Next job was to fill the void with foam. No pictures I'm afraid as things happen fast! I used the East Coast Fibreglass 2 part polyurethane closed cell product. It's VERY messy, causes a lot of heat and expansion force, but as long as your rudder is glued, laminated and has enough holes in to pour the foam and expand, it should be fine. I mixed it in a Chinese takeaway container with a teaspoon in a battery drill! I'd already drilled 36mm holes in the thick (stbd) side, and then got the grinder in there to make them more crater shaped when it all went off. A bit more bog to skin the foam, plus 4 layers of glass, and then finish off with filler, and it will look like the above and be watertight.



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Lastly a view of the leading edge showing the laminate going back down the sides of the rudder a few inches. Leading edge is 2 overlapping pieces of 50mm tape and then 400gsm glass cloth, giving a stepped 3-2-1 lay up as you work out from the centreline. Other edges are one piece of tape plus weave. The rudder has now had a smear of resin and light filler all over, and is now sanded smooth and awaiting 7 consecutive nights when I'm actually going to be at home and can give it 7 coats of VC Tar as the final anti-osmosis protection. And then, shock horror, it can go back on the boat!

The job has been a major PITA, expensive on materials, and time consuming, but a great learning experience and very, very worthwhile!
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