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Topic: WANTED: ISO Rudder Blade |
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Robert Brayshaw |
Posted: 27-Sep-04 09:45 |
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I have found a small crack in the rudder blade on my ISO near the top. Has anyone got a reasonable rudder blade out there without cracks before I hear ir snap? |
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phil the froggie |
Posted: 27-Sep-04 10:02 |
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Hi Robert
You can easily make a repair on your rudder blade.I made it myself on mine, 8 months ago, and have no crack anymore.
You only have to put polyester directly on the sandwich foam of your blade(you'll have to dig it a bit before) , on a large enough area to display pressure on it.
So you can sail with yours, without having to wait for a newer one.
Hope this will help. Philippe
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Robert Brayshaw |
Posted: 27-Sep-04 10:27 |
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Philippe
Thanks very much. I'll give it a go. How wide and how deep do I dig? I don't want to meet other ISO owners with a large hole in the rudder blade. I'd have to resort to lies and say it's a tuning aid.
Regards
Bob |
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phil the froggie |
Posted: 27-Sep-04 16:40 |
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I'd rather have worked at school, so my english would be better...
Anyway, when you make a repair on polyester, you must remove the same thickness that that you will add. (About 2mm on each side of the blade if you want to add 3 layers of glass fibre).
But take care:I would say 3 layers are the maximum.Your repair must not be stronger than the rest of the blade.It has to keep a reasonnable "flex".2 layers are enough for a thin crack.
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Pete Lindley |
Posted: 27-Sep-04 19:40 |
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What is wrong with drilling one or two long srews into the blade?
Drill from bottom front to top back angle. Do the polyester glueing or whatever, but re-enforce with screws.
Nothing seems to be wrong with my blades for some reason.
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Bob Ladell |
Posted: 27-Sep-04 23:06 |
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There are two types of blade out there :-
1 Foam with steel inserts giving it the strength - and weight ( which I have )
2 A two part moulded version that is foam filled ( which Pete has )
Type 1 are known for the small crack about 20mm or so long right at the bend point on the lowest part of the lower stock. This crack seems to extend as far as the first steel reinforcing rod and then stops. I fixed mine 2 years ago - for it to crack again in the same place only a few weeks later. Everyone I've spoken to about it says "they all do that - and keep going forever".
Type 2 have also been known to break - in various ways.
So far as I can tell, one of the keys to keeping your rudder intact is to sail flat and use your weight to harden up or bear away - i.e. as little heaving on the rudder as possible. Plus check that the blade sits *really* tight against the stock at all times - including at full speed. This saves a ***LOT*** of load on the rudder blade.
Any comment from the top of the fleet ?? |
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Robert Brayshaw |
Posted: 28-Sep-04 08:10 |
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Ha Haa! (Not a laugh but a 'so that's it' type of Ha Haa.)
My blade has small rust marks on it at various points. Only a couple and very small. I just assumed that it had been laid on something rusty. It seems mine may be the steel reinforced type. I shall relax a little then in the hope that it keeps going forever.
The rudder is after all a fairly irrelevant piece of equipment on our boat as its anyone's guess which way we go next. Looking forward to booking some training.
Bob |
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Pete Lindley |
Posted: 28-Sep-04 12:22 |
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The rudder follows the boat and steering is predominantly governed by boat heel and sail trim - all training course attendees (Buzz, ISO & Spice) will I'm sure remember this and understand the benefits - now they have tried their way and the definitive way as tought on such weekends.
Sounding like there might be a London based weekend sometime soon. Datchet / Queen Mary / Island Barn area.
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David |
Posted: 30-Sep-04 09:48 |
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Hi, As the breaker of three rudders (2 old and 1 new type), I think we have found the cure ? We spent hours trying to determine why, how etc with lots of people from the top of the fleet down !
The two old type rudders broke a big chunk under the lower stock like a large fish (thats a diff story !) had taken a bite and one blew the casting aswell. Both broke in a F5 fully powered up, and one with a kite.
The new type split top to bottom again in an F4/5 with the kite.
All 30 stone of us were holding the boat flat, not Andy Gould flat but ...
And this is the problem ... the rudder was under lots of pressure because the rudder had slipped forward in the tiller slots and therefore the tip of the rudder had moved back something like 30-40mm, causing heavy weather helm.
The resolution was to ensure the rudder is located right next to the casting. And to keep it there by adding stainless spacers in the tiller slot that connects to the rudder. These stop the rudder moving and loading up with stress looking to break weak points.
It seems to work real well now with no heavy helm !
My insurers are very relieved !!
I'll try getting some pictures of what we've done for the web Pete ?
Cheers |
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