Rudder bushes

[steve]

This is a response to a query Freetasman posted on the Facebook page.

Hi Freetasman,

The following comments apply to my Mark 3. I assume that this is the standard arrangement.

The bottom of the rudder has a stainless disc welded to it. The disc has a hole in it and it rotates about a stainless pin attached to the shoe at the bottom of the keel. Hence there is no bush at this location. If there is any looseness at this location it is likely due to the pin having become loose in the shoe.

There should be a non-metallic washer between the stainless disc and the top of the shoe. The non-metallic washer may have worn away and should be replaced if it is missing.

The bush fitted where the shaft exits the bottom of the tube (which encloses it as it passes through the inside of the boat) does not seem to be necessary and so there seems no need to replace it even if it is worn or missing. Replacing it will make the steering stiff unless the bush is perfectly aligned and the shaft is perfectly straight, so I would not replace it.

The bush where the shaft rises through the cockpit floor is the only one which is necessary to replace. The shaft is 1 inch (25.4mm). The inside of the tube into which the bush fits is 31mm (according to the design drawing).

If you are not taking the rudder off, you will probably find it impossible to remove the old bush. I did not want to remove the rudder so I cut the new bush in half so it was only semi-circular and pushed the half on which the shaft bears (due to gravity) down around the shaft as far as I could, then built up a support for the part which was still above the deck using epoxy and filler. When I took the rudder off many years later I removed the semi-circular bush and the original bush and fitted a whole new one.

There are some drawing in the Mark 3, sub-folder "drawings", in the gallery which you may find useful.

I hope this is helpful.

[freetasman]

Thank you very much for your reply.
I will order the bush or the material from Melbourne

[freetasman]

Thank you very much for your reply.
I will order the Vesconite bush or the material from Vesco in Melbourne
If I cannot get it then the second option can be using Acetal available in Tasmania

[Phillip]

I think you will find that the fit onto the rudder shoe is a vertical one only in that there is play horizontally otherwise we would have all sorts of problems getting the shaft aligned with the rudder shoe. There should be a nylon washer around 10mm thick sitting on the bronze shoe.

The cutless bearings that were originally fitted have to be cleaned up in a lathe to ensure they are centred.
I fitted a 3" long bearing in the top and bottom of the rudder tube and they were glued in-place with industrial strength Araldite.

On my Mk1 the originals lasted almost 40 years. So this something not done on a regular schedule but only when needed.

[freetasman]

Thanks again for the replies.
I assume that the washer have 1" ID, is that correct?
If I cut washer 31mm OD , the same diameter than the bush will be OK
Cheers
Arthur

[steve]

Hi Arthur,
No, the washer needs an ID to suit the pin in the shoe. The drawing says it is 17mm which is about right as far as I can remember. Regarding the OD, 31mm is probably about right although I cannot be sure.
Are you removing your rudder? If not, you should be able to lift the rudder about 10mm and install the washer if you first make a radial cut in it, depending on how flexible the material you are using is. It worked OK for me.

[freetasman]

Thank you.
I am ordering 2 bushes just in case that I ne3d to change the bottom one.
I prefer not to take the rudder out.
I was thinking in get one of the bushes cut lengths way to be able to fit it at the top if I find difficult to put one in one piece.
I would like to have the yacht for only 3 or 4 days on the slip.

[Phillip]

To change the rudder bushes you WILL need to remove the rudder as the bushes are glued in.
You need to cut [with a hacksaw blade] them length wise to be able to pry them out.
You will need to replace two of them, top and bottom.
Glue back in as I stated above.
To remove the rudder you will have to remove the rudder shoe so you may as well replace the four ss bolts that hold it on.
I use threaded ss rod of 8mm dia, 2x 100mm and 2x 110mm. Use two locking nuts per rod.
You will need at least 800mm clear below the keel to remove the rudder.

Trying to cut corners on this job will only see you coming back to fix it properly at a most inconvenient time!

[freetasman]

Thank you, perhaps I would need to remove the rudder when the boat is on the crane.

[steve]

Hi Arthur,

If you are being lifted out by crane (or travel hoist), have a drawing with you to show the crane driver the keel shape so he knows where to place the slings. If a sling is placed under the rudder, the rudder will be permanently damaged when the boat is lifted.

If you decide to remove the rudder, be aware that it may be a lot more difficult than you expect. The difficulties I encountered with my mark 3 were:-
a) Removal of bronze block which connects tiller to rudder shaft. Mine seemed to have been epoxied onto the shaft. I had to use a gear puller and even with that it was a struggle that took hours. You could try removing the bronze block several days before being lifted by the crane, and install it loosely to allow you to manoeuvre to the crane's position..
b) Removal of nuts and bolts from shoe. The nuts should come off (or the bolts break if corroded) easily enough. You will then have to hammer the rods out as they should have been bedded in polyester putty. Have a punch or smaller diameter rod available to drive them through the holes. The bolts on my Mark 3 are 3/8 inch.
c) Removal of shoe. When the bolts were removed, the shoe on my boat was still firmly held in place by polyester putty. A hammer and cold chisel were required to remove it. In contrast, a mate who removed his Mark 3 rudder told me the shoe just fell off once the bolts were removed. Tie a rope under the rudder and up to each gunwale before removing the shoe to prevent the rudder falling suddenly.

I am not sure it is practical to remove the rudder while the boat is being lifted by a crane. You should check that you will be allowed to, as some yards may consider working under a boat while it is lifted unacceptable risky, especially as you may have to hammer the shoe which may cause the slings to slip. (A competent yard will tie the bow sling back to the winches to prevent it slipping.) It may take you hours to remove the shoe.
When reinstating the rudder, you will have an even longer process as you should wait for the putty or sealant to set, then apply a few coats of antifouling, waiting for each coat to dry.

If the yard has a keel pit, you should get the boat positioned over the pit instead of trying to work on the rudder while the boat is lifted.
Alternatively, you could consider whether you really, really, need to remove the rudder.