Muir Thor winch rebuild

[pdbms]

I have a Muir Thor windlass on my 45' Hartley Tahitian. I have stripped it down to replace the bearings in the motor. Whilst pulling the covers off, I have found that there is surface corrosion under the finish (2pack paint) on the external housing and also on the side plates of the gearbox. Some questions:

1) Is the corrosion due to the steel bolts in the alloy housing? If so, how do I best prevent this from recurring?

2) Should I just bead blast the external housing and repaint with 2pack paint or should I get the external housing powder coated?

3) I think that the side plates of the gear box may, similarly, be corroding due to the steel bolts that fix them in place. If the gearbox housing is steel and the side plates are cast alloy (not yet proven - anybody know the answer?), will I ever be able to stop these from corroding?

Regards,

Kevin

[pdbms]

bump.

Does anybody have any advice on this?

[Bluetoro]

We have a Muir Thor here on the bench with a melted field winding and a cosmetically shot casing like yours. We anticipate using an LP paint since we can control the process ourselves, and warrant the finish.

[Bluetoro]

Photo of the Muir 4000

[noelex 77]

If it was me I would remove the paint on the external housing and leave it as bare aluminium. It does not need paint to stop corrosion. With the amount of disimilar metal around getting any paint to stick is going to challenge.

If you do paint it you need to follow the guidelines to the letter.
International would recommend 5 coats of epoxy interprotect then 2 coats of undercoat then 3 coats of perfection.
Other pain system require a different procedure often with an etch primer.

Power coating does not work well.
Anodising is another option with a small part like this. You can even do this youself with smallish pieces.

Wherever you have SS bolts going through aluminium you need to protect the aluminium with a product like Duralac.

The main weapon against the disimilar metal corrosion with the internal parts is to keep the components dry. Easier said than done, but at least try.
Spraying the internal components with one of the car cavity wax corrosion protectors is worth doing.

[Bluetoro]

...Painted after sandblasting and awlgrip awlfair hi build primer and offwhite IMRON LP.

[Bluetoro]

pic should be attached this time...

[TonyQld100]

Back again.
Hi ,would you have any idea of the cost of a replacement motor for a Muir Thor,Jusy wondering if it is worth renewing.