Treating rust on steel motor parts

[matt1]

After removing the cover, I’ve found some rust on parts of my bowthruster motor. Typically small “delicate” parts like coil springs etc. Lots of copper in evidence, all of which looks good. It’s the stell parts that have rusted. I’ve cleaned them up and removed most of the rust mechanically and with Kurust - the question is what should I coat the parts with? WD40? Grease? The parts are at the top of the motor and probably get warm as there is a fan blade mounted above them and ventilation holes in the cowling that covers the motor.
I don’t think painting the parts is an option, partly because they obviously flex a fair bit and also because it’s very intricate being basically part of the electric motor

 

[Boater Sam]

A thin smear of high melting point grease but keep it away from the commutator and brushes. Not Copperslip! WD40 is only a water dispersant, useless.

 

[CM74]

ACF-50 maybe? I've had a lot of success with using it on motorbikes - like wd40 it displaces water but it clings and prevents rust well.
It doesn't seem to affect most rubbers or plastics either, and can be used on electrical connectors. (Wouldn't let it near any commutators, brushes or that sort of thing, but can be sprayed into switches and so on no problem)

It's expensive (£15 for a big spray can) but you can use it on things like outboard motors too, or anything else that lives outside and needs protecting

 

[Momac]

My bow thruster motor etc showed slight corrosion . I gave it a smear of Waxoyl. That was in 2014 and it has not required any further attention.
Alternatively I would use petroleum jelly, which I have on the boat anyway and use on battery terminals and the like.
Only a light smear if the product is required.

 

[V1701]

ACF-50 maybe? I've had a lot of success with using it on motorbikes - like wd40 it displaces water but it clings and prevents rust well.
It doesn't seem to affect most rubbers or plastics either, and can be used on electrical connectors. (Wouldn't let it near any commutators, brushes or that sort of thing, but can be sprayed into switches and so on no problem)

It's expensive (£15 for a big spray can) but you can use it on things like outboard motors too, or anything else that lives outside and needs protecting

+1

XCP Rust Blocker is another good one, I use that for areas that get wet regularly, it's thicker and more sticky hence stays put for longer...