Rudder Problem?

If there are no cracks then the fleX will be over a big area . stifferness and stringers for the skeg would be a good idea !!,Just remember to stop all that flexing its got to be a really strong addition you put in there !!so dont just add extra glass layers and exspect that to fix your problems because it wont !! Its going to need a good frame and solid glassing so fun and games!! strip as many things out of there as possible and grind and 100% clean the glass surface so the new glass and glue etc will stick and never come off . Its a side ways flex so the frame will have to go across and as far out each side as is practicly possible , and if you choosing wood make sure its good stuff and 50 mm thick at least .
As the bearings have worn so the skeg had began to move so one is causing the other to happen.
Funny over the years have made lots a yachts the same as that but never had that problem before ever !!!!.

 

I pretty much concur with tunnels.

Eric

 

Agreed, it's not a localized issue. Some gussets and/or stringers may be in order to limit the hull flex. Do you have room for a ring frame?

 

Stringers going across and out as far as you can each side and make sure its got lots a glass over it at least 100mm onto the hull around the whole of the timber . The bonding to the hull is critical so make it big !!theres one hell of amount of strain going on there when the boat is hard out and going for it . I would also pay special attention and go all over the rudder blade with a magnifying glass looking for stress cracks !!
HOW IS THE BLADE FIXED TO THE SHAFT ??
TAKING THE FLEX AND TWIST FROM ONE PLACE IS GOING TO THROW THE EXTRA LOAD SOME WHERE ELSE AFTER ITS FIXED !!

 

Thanks for the input. I got an e-mail back from Tony Castro. He suggested that the gussets should have been 5 times larger! Additionally I got some info from another CS40 owner. The earlier builds included a bearing laminated to the floor of the lazarette but no gussets. Attached is a photo to illustrate. I'm speculating that in the later build, they didn't include an upper bearing but added the inadequate gussets to compensate.

My preliminary plan is to add some laminate to the inside of the hull, add a stringer behind the rudder tube, extend the lateral gussets to the cored part of the hull, laminate everything in place and add another bearing to the top of the rudder post laminated to the floor of the lazarette. Essentially the addition of the upper bearing should correct the flexing and the additional laminate and stringer is to add insurance against what was obviously a weak build in this area.

 

Is the rudder shaft hollow or solid ?? Have you checked to see if its bent any where ??
With all the straining and shifting of the skeg etc etc i sure as hell would be doing my home work on every single part of every thing to do with the rudder !!!.

The 38 foot racing yachts we made in Korea had a long spade rudder and a bearing in the hull and another throught the cockpit floor and the shaft was made to bend when underload so the hull bearing and seal assembly was self aligning as well as the top bearing through the floor . Everything was pre-made in France and fitted and operated absolutly perfect !! it was one finger operation even when hard out and going for it was so light to steer .

 

The rudder shaft is hollow, 72.7 mm dia. I'm not sure of the wall thickness. I'll check for straightness when we get the rudder off the boat but three years ago it was straight. Hopefully once I stiffen the skeg and rudder tube the additional load doesn't bend the shaft!

Thanks,

Mike

 

Does anyone want to wax eloquent on ring frames?

 

Ring frames are bulkheads with a big hole in the middle, to put it in simple terms. They can be oriented athwartship (typical) or longitudinally (commonly seen in commercial craft).

My thoughts with the ring frame were, to get a good purchase at the top and bottom of the tube (tabbed to the frame), with bonding to the hull shell all around the frame, which will spread loads over a large area and still provide good access to it and areas around it. Big gussets on the other hand, will use less material and tabbing, but also will block access to areas near those gussets and not spread the loads as much as a ring frame.

 

Just finished a few days ago. New bronze upper bearing. Took the rudder tube out of the structural picture. Now it's just there to keep the water out.

This will put my CS40 in the same camp as those built in the 80's. Had it out for a sail yesterday. Still has a light touch on the helm so I think things are balanced pretty well.

 

So its all good news !!! Always good to hear some good news for a change even if we didn help that much . take care and pleasent sailing where ever you go !!

 

Is CS still in buisness ?? I'm blown away at such poor construction coming out of a company known to produce a quality product. This fault in engineering and construction definately falls under the heading of "Factory Fault" and like the automotive industry should have been a recall due to possible life endangerment.Which in this case for the want of enduring a majour storm before you reaching port could have resulted in a sinking. Wonder how many more CS 40's are out there undergoing the same structural failures being sailed by skippers not as aware as you were in this case. MMMmmm -- Is anyone aware of a marine site where such majour faults are reported or listed for the benifit of all to gather info and make necessary corrective repairs other than what seems to be word of mouth ??

 

Most i would say . I have been in the fibreglass boat building since 1972 when i first inhailed styrene for the first time . The cover ups and near disasters are almost a weekly occurance in some places an because it happens so often its just taken as being normal and no one takes that much notice !! Thin glass is a real problem from companies using chopper guns , Its completely up to the guy hanging on the end of the gun as to what sort of a job you get .
If hes having a bad day like we all do you could get a thin boat . so check if the boat is hand laid or do they use a chopper gun !! so many do !!
Its why so may companies put them away and went back to hand laminating and buckets and rollers again so there boats got a more consistant layer of glass over the whole boat . Or took the chopper off and use them as a saturator gun !!
So where and who do you point the finger at ?? the operator or his supervisor for not regularly checking the quality of workmanship in the whole factory , When i was a factory manager I made it a rule one day of the week i put on overalls disconnected the phone and went and worked with the guys doing what they did using the same gear etc etc , that way i knew what they knew and there were never ever problems !!.

 

I wouldn't be so quick to judge. The company has a good reputation for a reason and there's no such thing as a manufacture that hasn't produced a bad egg every once and a while. Not to mention it could be an impact or other reason for the problem, possably compounding a marginal build.

 

Tunnels, I would say your work practise would be the exception rather than the rule. It's a case more than ever of buyer beware with the price of resin rising in unison with crude. One definately needs to do his homework on a craft before laying down that hard earned cash. Yes I often heard it said and also from my own experience in doing repairs and alterations at the shop the older heavy hand laid hulls are definately stronger built. The one problem I did encounter more but not often on older hulls was blistering and I suspect this was the growing pains (manufacturing enviorment learning curve) in the industry. It's in my nature to do alot of research on any expensive item i purchase especially in the automotive field and would be more so if I were purchasing instead of building my own vessel. One more good reason to be active on a forum related to the product --