spraying alternator

[Gunfleet]

If any water gets into my 26 ft sailboat it usually collects in a sort of false bilge under the engine, from whence it is capable of rusting the alternator at amazing speed (!). I think a light spray of oil on the alternator would stop it. Should I do that or is there another product?
Thanks
John

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[Alex_Blackwood]

If your alternator is being sprayed with water. Is it salt? I would be worried about the effect of this on the windings and internal components and connections of the alternator. Nothing worse than salt water for destroying the insulation and leaving you with a burned out alternator. I would be looking at some means of protecting the alternator with some sort of mechanical shielding to prevent the ingress of water. I would be looking at this in conjunction with whatever else you do to stop the rust problem. I don't think spraying with oil is a good idea as this in itself will cause problems if it gets into the windings. Whilst oil is an insulator it has a habit of going sticky and you will end up with all sorts of gunge stuck to the windings. Even if this is not corrosive it can be detrimental to the air flow through the windings.
You could try a good coat of something like Hammerite on the externals.


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[LadyInBed]

Do you actually get ingress of water here - you start your post with If.
Does the false bilge drain or do you have to pump it out?
If you have to pump it out, you could float some oil onto the water to act as a barrier.
Sprayed water around the engine area is probably caused by a leak somewhere in the cooling system getting onto the fan belt. The belt sprays it around.
As for the alternator, I would rub high temperature grease over the body and spray 3 in 1 on any aluminium.


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[Gunfleet]

Thanks to you and Alex both. My boat is a very traditional shape, with a big cutaway on the stern. So the tray under the engine is about as deep as it can be = not very. This means that any water ingress (when someone - moi? - forgets to turn the greaser every hour) ends up in the tray. The small amount of salt water is spread around by small scale turbulence around the engine and alternator and leads to rust on any bare surface. Yeah, I'm getting the stern gland fixed to accommodate a forgetful owner, but I know very well I'll still end up with a litre of salt water in there now and then.. and that's enough. What do you reckon of that waxoyl stuff they sell for car underbodies?

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[LadyInBed]

Waxoyl will do a job, but as it sort of goes hard, any salt trapped under will just eat away, on the other hand, when you rub a handfull of grease on you will feel any blemishes.

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