Month: February 2018

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Sunday, January the 7th 2018

More repairs – part 1

As it seems, I had not enough by just repairing the rudder this winter and so I opened up a few more jobs. There is the cutlass bearing that I will replace and also the Volvo shaft seal but some other problems showed up too.

The HR 352 has a very classical type of cutlass bearing housing. It can be unscrewed with the help of a large pipe wrench and some effort after removing the two locking screws.

A polyurethane sealant (Sikaflex 291i?) was used most likely for sealing the bearing housing against the hull but it was also applied on the thread.

The Centa-coupling needs to be disassembled if the Volvo shaft seal is to be replaced. When I started I realized that the water that had entered the boat in Gibraltar in 2015 had led to some corrosion at these parts although I had washed everything with fresh water as soon as I could. It took me about 4 hours to remove the 6 screws fixing the rubber parts to the flanges. One of the 6 screws that hold the rubber parts on the connecting tube wouldn’t let go from the rubber element and so I had to destroy it. That is another EUR 120 for a new rubber element on this season’s list :-)

These screws gave me a hard time…

The coupling is out…

…and so is the propeller shaft from the coupling flange as well as the Volvo shaft seal.

When I detached the bearing of the Centa-Coupling from the bulkhead, I found another problem.

In the mounting instruction, the bulkhead A is supposed to be a solid part, either metal or solid GRP but not plywood. When the bearing was installed on Matilda’s plywood bulkhead which was added when the engine was replaced, the installer should have used big washers on both sides of the bulkhead. Since that wasn’t done, the bushes 1.17 were pressed into the plywood resulting in a loose connection (Centa is specifying a tightening torque of 79 Nm for these screws).

The Centa coupling was taken apart and cleaned piece by piece and is now ready for reassembly.

There has been a small leakage at the ruder shaft tube (between the tube and the GRP) from the time I bought the boat back in 2014. Nothing serious, but since the rudder is off now, I will address this too.

This is how the area looks around the rudder shaft tube after removing some putty.

The picture shows the rudder shaft tube with the stuffing box housing inside the boat. Hallberg Rassy had used silicone for sealing this end. I had poured a few liters of fresh water around the stuffing box and let them leak through to the outside in order to wash out the salt that may have accumulated along the leakage path.

…to be continued in part 2

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Sunday, December the 28th 2017

Rudder removal and repair – part 1

It is done. Matilda’s rudder is removed. I must admit that although I had read almost everything I could find on the web about accomplishing this task, it has not been a straight forward operation.  There is also a description from Hallberg Rassy which gives confidence but some people managed to bend the thread at the rudder shaft end or needed an electric file to remove the locking key step by step as the shaft was coming out of the upper bearing together with the locking key. Since it does not fit into the rudder shaft tube it has to be removed somehow.

Here is Matilda’s rudder removal and repair story:

The task starts with removing the putty all around the bearings in order to free them and get access to the screws and the nut at the shaft end. This has been described many times but it is a different thing reading about it or doing it.  You normally don’t “treat” your boat with a hammer and a chisel and it took me some time to get started. Once started, this task is quite easy. You only have to be careful not to damage too much of the gelcoat (although repairing it later is not an issue).

The nut at the end of the rudder shaft comes free as the polyester putty goes.

Some people reported that there was a washer under the nut. There isn’t any on mine.

Not sure what putty was used here… epoxy?

The area underneath the upper hinge at the port and starboard side of the rudder were also wet and I decided to remove the putty wherever it wasn’t too difficult.

The next thing you have to do is to push the shaft out of the upper bearing. What is needed here is a custom made special gear puller that fits around the upper bearing.  I used a pair of wedges for this as described in Hallberg Rassy’s instructions.  After I had positioned them carefully perpendicular to the rudder shaft axis, the shaft came loose easier than I had expected. Unfortunately, the locking key was stuck to the shaft and was coming out together with it. I have used the locking key from the steering quadrant which I placed between the rudder shaft key and the rudder tube in order to hold it in place whilst the shaft was forced upwards. This was the most painful part of the operation. I used some heavy duty wedges (which were at least 5 times the size of the ones I had prepared for the job and I also used some posts which I had to put into the bearing as its end with the nut was disappearing into it. I was reluctant when I started hammering on the wedges because there is quite some force applied to the rudder shaft tube which pushes it up into the boat’s hull but since I had to repair a little leakage there anyway, I became more courageous with every stroke of the hammer, especially when I saw that the rudder shaft was moving but the locking key was hold back against the tube and the tube itself was steady as a rock. I took a while but finally the rudder shaft, the locking key and the upper bearing were separated and the rudder could be removed.

The smaller wedges were carefully positioned perpendicular to the axis of the shaft.

The rudder quadrant and the autopilot gear had to be removed prior to the operation of course.

The rudder shaft with the stuffing box packing gland at the left side of the picture and the nut on the right side

Good news is that with the exception of some gelcoat scratches here and there, nothing was damaged.

The part of the lower bearing that was mounted to the skeg was not very easy to remove because it was bent around the skeg and needed to be opened to get it out. It won’t be easy to put it back on place again as it will need careful adjustment in order to be in line with the ruder shaft tube axis.

Four 3mm thick bronze plates (approx. 15 mm X 20 mm) were placed under the lower hinge (arrow shows location) on both sides at the skeg most likely for adjustment and fixation. (correction June 27th 2018: the alignment plates were mounted only on the side shown on the above picture. More pictures and information on the post from June the 27th) 

The lower bearing can now be removed completely.

The parts comprising the lower bearing look better than I expected and would probably have done their job for at least another 35 years.

The play in the lower bearing was about 5 mm (compare two pictures above).

The bores are still round but don’t have the same diameter all the way though anymore.

The pin showing some abrasion especially in the middle section where the hinge parts meet.

I will rework the parts back in Germany where I have the luck to have access to a nice little machine shop and can count on the help of my very experienced colleague and friend Robert who had also joined me on the 3rd leg from Lisbon to Gibraltar on my trip around Europe.