Rudder delamination - TWICE !

[Andrew2012]

Hi
I wonder if anyone has experience a delaminaton of the rudder, I had a major delamination in Jan-Feb 2015 with my right rudder ( it was about 12 months old) and replaced it in Feb 2015 with a new one.
I can now see the beginning of the same damage in the new rudder and if it goes the same way as the last one it will only last another 2-3 races.
The left rudder is still as good as new and is now 2 years old. I had no bottom scrapes and both rudders have the same angle when fully deployed, so similar stress level.
The boat is one of the early and few Tattoos made, but I think the rudder itself and the setup is identical to the 26M so I am wondering if this could be a Batch problem?? Any suggestions...
I do several Club regattas usually in 10-18kn but this year I did only half as last year (about 15 races since the new rudder).
The boat is on its trailer when not sailing and I always give it a good wash at the end of the race.
I am also considering replacing both rudders with an aftermarket model (can I trust a Mac rudder for the 3rd time ??), the company I was considering is :
http://www.ruddercraft.com/catalog/inde ... =3a&page=2

Has anyone used products from this supplier?
Any help would be most welcome.

Original rudder Feb 2015 (12 months old when damage appeared)


NEW RUDDER- only 10 months old


Thanks
Andrew

[Norca]

Mine are doing the same thing.
I have repaired with epoxy, I poured it in to the cracks, but it has a couple of times now, and is probably not as strong as before.
The lower part is hollow, and I think water must get in during winter months and then freeze,
Frozen water can cause a lot of damage so I took them inside the house this fall
Hopefully that will prevent more cracking.
I guess it crack from freezing during winter, and although not visible the rudder is already weakend, and then in season it crack the gelcoat and the damage becomes visible.
I also had the rudder-bolts breake and the brackets bend
Gues I sail harder than most I msured 30 knots wind last summer
I blame it on the ice anyway

[Ixneigh]

Where do I get those extra thick washers you have on the rudder brackets?
I've had good luck with the Ida rudders.
Concur possible freeze damage.
Ix

[Norca]

After braking the rudder-bolt TWICE, I upgraded to 1/2" bolt and I made a bushing in
the rudder itself with a 1/2" nipple epoxied in the fiberglass.
The fit was near perfect between the bolt and the nipple, so hopefully noe more
problems there.
Great idea with the washers Andrew, I see Your brackets are bent like mine, I had them strengthened
with some stainless flatbar welded in place.
Now You have to use the boat more, there is cobwebs growing on the rudders

[Andrew2012]

Thanks for the reply.
The extra thick washers have been done by a friend (Engineer) and they do work well, but you have pointed out I see that there is a bending of the brackets, so I will take up your suggestion and strengthen them somehow.
I may give it a go with the Ida rudders, thanks for the positive feedback.
We never get temperatures below freezing here in Western Australia so I think the most likely cause is stress fracture of the gelcoat followed by water damage and delamination, I am puzzled on why it is always the left rudder.
We do occasionally get the 25kn winds in the middle of a race but I try to only race if below 18kn, than again a good part of wind forecast is a bit of a guessing game...

2 weeks without sailing and I get cobwebs ... Today I managed to find the offending spider and relocated it far from the boat

[Highlander]

Have u been powering too fast with the rudders down over stressing them , or over tightening the bolts , I have the ida rudders with no issues but their have been a few with breakages

J

[Norca]

For me, never over 6,5 knots under power, but I have seen 8 knots under sail on the GPS, with no current, but the waves pushing
in the right direction. That should not be enough to delaminate the rudders.

[Andrew2012]

I only motor and have the rudders down when maneuvering near the Club and/or mooring, with some dagger board down for extra control not more than 3-4kn, so I don't think I damaged it that way,.
When sailing in over 15kn and close-hauled there is a reasonable amount of pressure from the steering wheel, I always try to balance the boat by controlling the balance between the Main and the Jib or Genoa but that is often not enough and the rudders are under some stress. I would have thought that they would have engineer the rudders and attachment brackets to handle such stress, but I am suspecting that perhaps it was geared more to a kind of easier sailing (less than 10kn and not too close-hauled). If this is the case and I want to continue Club sailing I may need to find a way to strengthen the whole steering setup. I am starting to wonder if I also need to have a second look at the controlling cables.
The bolts are tight enough so that the rudders don't move around too much but loose enough so that I can pull the rudders up or down without too much effort, I even give it a quick silicon spray before going out to lessen the friction, it makes such a difference.
Anyway thank you for your ideas and input.

[seahouse]

Part of the problem stems from the clearance space of about 1/16” between the rudders and the two tangs of the rudder brackets (total of 1/8"), presumably as a tolerance for the manufacture and assembly of the parts.

When the pivot bolt is tightened it brings the tangs together against the rudder surface (contacting first at their tips) which makes them converge at the ends, since they are welded at the pivot tube and cannot move inward at that end.

Further tightening of the bolt will continue to bring more of the tang surface into contact with the rudder by flexing, and maybe bending the tangs. But this will also place excessive point force at the area of the tips where the initial contact was made (even though the rudders might still be free enough to swing).

Also notice that it is unlikely to give much, if any contact (and hence support) with the rudder at the half nearest to the steering pivot tube, where the welds prevent it from moving inward (unless the bolt is excessively reefed, which would crush damage the rudder, or even shear off the stainless steel bolt).

The mod in the following link shows a solution to this problem. It fills the space with a low-friction industrial bearing material that allows the tangs to stay parallel to each other when the pivot bolt has been properly torqued. It has worked perfectly on my boat (and a few others here) for 4 seasons. It spreads the forces evenly over the entire bearing surface where the rudder and tangs contact, and allows the pivot bolt to be snugged without excessive up and down friction when the rudders are retracted. And it is essentially invisible.

It is the fastest, easiest single thing you can do to strengthen and reduce play in the steering (unbolt the rudder, install spacers, tighten back up; do it sitting down in a chair if you like). A search of this forum will lead to a few discussions on the topic. (If the tangs are already bent they will ideally need to be straightened before these are installed).

You can make your own as I have described in the mod link, or I have a couple of spare sets of these made up (US$50 including shipping), if anyone would like a set email or PM me for details.

http://www.macgregorsailors.com/modt/in ... ?view=1590

- Brian

[Andrew2012]

Many Thanks Brian !
It makes sense, and keeps the rudders from flopping around too much.
Will give it a go and report back

All the best
Andrew

[BOAT]

The rudders fill with water in the down position, then when we raise them some of the water is inside the rudder - the top of the rudder is now on the bottom when the rudders are all the way up. That means some water is still trapped inside and resting near the top of the rudder. I often remove my rudders to clean and polish them and I always notice a little water comes out as I flip the rudder awound in my hands.

If you are in a freezing situation, the water is in there freezing at night and melting in the day - back and forth, day by day. The water could force it's way into the top of the rudder where the wood core is by creating cracks. Eventually - well, the pictures paint the "eventually" pretty clearly.

What is surprising to me is that the rudder in the picture seems to have a wood core made from a multi ply wood? The wood core on 'boat' is a solid piece of wood. When did they start using multi-layer or ply types of glued wood in the rudders? The IDA rudders are solid wood, right?

[jimmy alonso]

Looks like the rudder bracket is bent from the posted picture. I had a rudder do this too, the right one also. My bracket got bent one day motoring too fast in big following seas with the rudder down. The waves turned the boat sideways a couple of times and the rudder cracked like yours and the bracket was wider at the top than the bottom. I removed the bracket and straighten it the best I could put some screws and fiberglass on the rudder and used it like that for a year or more maybe. Your best bet is get a new rudder and bracket.