Replace rubber stern gland/bearing??

[exapp]

Howdy folks,

Have rubber stern gland seal that is essentially a rubber bearing. It was damaged by rope around the prop and part of the carbon fibre stern tube has been worn off. This part of the stern tube held two nylon screws that stopped the stern gland seal/bearing from rotatiing or moving out of the stern tube. Think of an inch and a half of a tin foil cardboard tube extending 1.5 inches out of the keel skeg...now it's only 0.5 inches.

In order to repair the damage i need to file off what is left of the stern tube untill it is has a uniform face that will take the seal. Unfortunately this will leave me with no place to fit new nylon screws (that i would have to have made anyway) so i was planning to bond the rubber stern gland seal into the stern tube to prevent it rotating with the prop. It is a very tight fit anyway.

I plan to use a 2 x pack super epoxy Will this be adequate for the job & is it marine proof. Has anyone ever done the same job? If so any advice?

Regards,

Exapp

 

[Transcur]

I guess you are refering to a cutlass type bearing. I have phenolic resin cutlass bearings bonded to the P bracket using ordinary epoxy. I have not had to remove them yet but I plan to heat up the P bracket to soften the epoxy to make removal easier. They slid into the P bracket with light hand pressure when new. No sign of wear and no movement at all,- so no problem.

 

[TigaWave]

I wouldn't like to pass any comments on the damage and repair, without seeing the boat. Also, as you have a composite stern tube you may not want to use resin to bond a bearing as you will need to heat the bearing to allow its easy removal when it needs replacemnent... but in answer to the epoxy use on bearing question.

Composite bearings are routinely installed with epoxy resin in bronze bearing carriers, they are usually a fit that allows them to be spun by hand (0.2mm clearance) which allows you to ensure that the shaft is alligned.

Make sure you don't use high temp epoxy as you will want to heat it when it needs changing, but as I've suggested bearings need to be removable and epoxy in a composite stern tube may not allow this in the future.

Epoxy fine for securing bearings....but your set up may need more thought or a different solution to allow for future maintenance.

 

[cliff]

Do you really want to be fooling about with a Heath Robinson repair? Replace the stern tube and be confident the seal will not move or leak in the future.

From what you describe you have already lost 1" of the tube projection so I would not be confident in any attampt to "bodge" a repair - stern glands are critical for the boat to stay afloat after all.
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[kengill]

Does the seal have to be external?

The volvo seal is fitted internally onto the stern tube and if you have room to fit it is easily maintainable. Just remember to "burp" the fitting to remove trapped air each launch and squeeze a bit of grease into the seal every year.

 

[exapp]

Thanks for advice all. Just to add the bearing isn't really a seal and is designed to be lubricated by water passing through it. Replacing the stern tube would cost thousands i'm sure as it is glassed into the hull. My only fear was that the bearing would rotate with the prop but it looks like the epoxy would do the trick. I would expect the new bearing to last a good few years and i am prepared to cut it out whenever it needs changing. I won't be able to back out of the tube either as i'm fitting a rope cutter behind it and i will also be getting the engine + shaft professionally alligned.

Regards,

Exapp

 

[Skyva_2]

I would be really careful to check that rubber and epoxy are a suitable combination. If it fails the consequences are not to be contemplated....

This is not a bearing or cutless as I understand it, it's a stern tube.