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Old 05-10-2017, 23:30   #16
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Re: Beneteau First 47.7, Stiff Rudder and Stuck

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Originally Posted by frant View Post
This is not supported by studies and is perpetuated by paint manufacturers. Trilux 33 has approx 20% cuprous oxide as active ingredient. Longlife has approx 35% cuprous oxide. Cuprous oxide is less noble than copper (closer to open circuit potential of an alumimuim saildrive leg) and in any event is electrically isolated from the aluminium substrate by the carrier resin. There have been several corrosion studies on this matter that conclude that there is no benefit to the lower cuprous oxide content paints. I am presently running an in water trial on saildrive leg to demonstrate and paint my own saildrive and housing in Longlife to extend the time between antifoul.
However I do stress the importance of maintaining and monitoring the anode system.
Trilux 33 is specifically called out by the manufacturer as being for aluminum substrates. Most bottom paints are higher Cu content and are specifically called out as not for aluminum substrates.
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Old 05-10-2017, 23:37   #17
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Re: Beneteau First 47.7, Stiff Rudder and Stuck

Having been partially through this mess on our old boat (40.7) and seen it on too many others, once you've removed the race and everything else there are two additional things to watch for. First, the aluminum tube is bolted into the aluminum race with steel screws = corrosion central. Make sure to bed them in e.g Lanocote and consider getting different screws. Second, I'm reasonably sure the roller bearings in the Jeffa bearing have some carbon in them, which again starts the corrosion rolling. In addition to bonding I'd strongly recommend packing the bearing full of Lanocote or similar, probably every other year.
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Old 06-10-2017, 18:54   #18
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Re: Beneteau First 47.7, Stiff Rudder and Stuck

Hi All, update from the day in the shipyard;

I ended up leaving the original bearing housing in the boat. Cleaned out all the corrosion and coated the inside of housing with West System, cavicil and powdered Aluminium to seal the bare aluminium inside the housing. This was then sanded for bearing to fit.

I have an interesting discovery while trying to remove the top bearing from the housing. When I first tried to remove the bearing, it was not going to budge, I then banged on it with a 4X4 with little movement. If you don't remember from my first post I am in Mexico it is hot here, 95 degree F. I had a flash, and put the whole assembly in the ice chest with the icy water. I pulled it out after 10 minutes and I could easily by hand pull the bearing out...!

Knowing what I know now, if faced with removing the bottom bearing in a hot climate, I would pack ice around the rudder tube before trying to remove the bearing. Corrosion was the main problem, but I think I would not have needed as much force to remove the rudder if I had packed ice around it.

Rudder goes back in the boat tomorrow..!

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Old 06-10-2017, 20:23   #19
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Re: Beneteau First 47.7, Stiff Rudder and Stuck

Prior to reassembling things consider this. You have carbon fiber, stainless steel, copper, aluminum, & ??? all mixed together in seawater. One or two of them is definitely going to lose that fight.

Also. Pounding (or hydraulically pressing) on carbon fiber is no panacea, nor risk free. You can do significant amounts of damage to it without the damage necessarily being visible. Particularly in thicker laminates such as rudder tubes. As damaged fibers can be surrounded or enveloped by others which appear fine. And determining whether or not there's damage, & if so, how much, can take more complex testing than occurs on a work bench, or via magnifying glass.

I mention this as plenty of rudders with carbon fiber shafts that have sustained impacts, & even ones that haven't, seem fine... until they suddenly snap. And there are plenty of case studies out there on this, including on some of Beneteau's more race oriented designs. Ones with carbon fiber stocked rudder shafts.
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Old 07-10-2017, 12:11   #20
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Re: Beneteau First 47.7, Stiff Rudder and Stuck

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Originally Posted by O_salt View Post
I have a 2001 Beneteau First 47.7 with a rudder problem.
The rudder is stiff when turning, this is the second time I have had this problem. The first time it was caused by a head of a SS screw that had broken off on the shaft chase and jammed up the bearings and the bearing carrier was turning inside the bearing housing. I was able to get the rudder out by banging it with a large block of wood with a sledge hammer. I replaced the bearing chase with a new Jefa bearing made for this housing. I did not replace the housing.
Currently I am on the hard in Guaymas, Mx. I have done the following things;
Removed quadrant
Removed SS pin
Removed SS hose clamp
Moved V-gasket up the rudder shaft
Removed top retention rod and thrust bushing
Rudder does not want to come out, the rudder is impossible to rotate by hand, using two 2X4 as a tiller on the rudder blade; it is still very hard to rotate the rudder.
I have poured vinegar down the shaft from inside the boat, I worked the rudder back and forth, I then used a 4X4 block and a sledge hammer to try and drive the rudder out. (This is how we got the rudder out before).
Anyone out there had any experience with this? Any suggestions for getting this rudder out?
Did I miss anything? One of the things I will try tomorrow is to remove the top bearing Chase and carrier as that is removed from above deck.

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I have had a similar problem on our Bavaria. The seizure was widely anticipated to be an issue with the bearing material swelling due to water absorption, however it wasn't at all in my case. It was due to water ingress and bearing housing corrosion, bein an aluminium alloy. The corrosion built out and caused compression on the bearing which in turn compressed onto the rudder shaft making it almost impossible to turn. The top bearing was fine being above the water line. I listened to a lot of horror stories about beating the living daylights out of the top of the rudder stock with sledge hammers- but I think there is a better way. It certainly worked for me.

The total weight of your rudder hanging in the bearings is substantial. Use this weight to advantage and also the flexibility in your fibreglass hull. The only force I used to shift the rudder was the moderate weight of a rubber mallet. The problem with shifting your rudder shaft by banging on top of it is that the flexibility of your hull takes most of the shock on impact thus absorbing it and nullifying its effect. Not to mention what you might do to the top of the shaft. What I did was use that property in reverse. I hit the area of the hull directly around the rudder stock upwards from below. The spring in the hull works upwards and the weight of the rudder, or rather its inertial moment tends to keep it in the same position while the hull "creeps" up on the shaft. Little by little the shaft came out with no damage to hull or shaft. Imagine an automobile suspension. The weight of the car and its resistance to upwards pressure because of inertia is what makes shock absorbers able to do their job. You see the axle tramping up and down violently with the variation in road surface but the vehicle's body continues on almost the same plane. It's the same principle.

If you want to improve on this principle add static weight to the top of the rudder shaft and use the flexibility in your hull.
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