Aluminum corrosion

[capta]

I have been looking for something that will clean and stop corrosion on my Lewmar 65 winch bases, but have had no luck. They are corroding at the base where the winch mounts to the teak and on the sides where the black sides protrude (apparently not structural?) above the internal base.
Anybody have any idea of a product or chemical which will clean these areas well enough to prime, glue and repaint? There is no way to sand or clean these areas w/o removing the winches, and that is a huge job.
I am in the Caribbean, so I need a product that is readily available almost anywhere down here.
Thanks.

 

[centerline]

that looks like an aluminum mounting pedestal... not part of the winch itself.... if you plan to repair it, stop the corrosion and continue using it, you will need to remove it completely and give it an acid bath to remove the corrosion from every part, nook and cranny of it, then treat it with a corrosion inhibitor for aluminum, paint, then reinstall.

this is not a permanent repair, as it will happen again in a few years or sooner...

or you can build new pedestals for the winches out of delrin that will outlast the boat without any maintenance..... as you can see here

 

[Bill Roosa]

Nothing will stop this kind of corrosion. You have SS in the winch and aluminum in the base. It WILL corrode due to the aluminum acting like a zinc. If you electrically isolate the two that will stop the corrosion but that will introduce a mechanical problem since the winch base has to handle high lateral loads.
I'd recommend going with a wood or plastic.

 

[Cayennita]

On a Lewmar 65 the aluminum base is not just for looks. It houses most of the gears besides the mounting screws, etc. you do need clean it completely down to the base metal and reseal before painting or leave it in it's natural state. Polish as needed.