Saildrive Leg Painting

[emandvee44]

I was re-fitting the shiny polished propeller when I noticed the paint/anti-fouling coating had broken down in several areas and in fact the aluminium was visible.
Therefore some treatment is required!
I did a search on the Forum and read all the threads on the subject, of which there are many, but could not reach a conclusion as to the correct procedure.

This is what I am planning to do.
Scrape off all the anti-fouling and original paint.
Rub down the bare aluminium with Aluminium oxide paper.
Apply 2 or 3 coats of epoxy primer*
Then apply an enamel top coat
When dry, lightly key the enamel and apply the usual spray on anti-fouling, something like mille drive (or whatever is available out here)

*The epoxy primer (Titan) is claimed to adhere strongly to aluminium and other surfaces, and therefore I do not think etch primer is necessary, and it is not mentioned in the surface preparation advice on the tin.

Any comments?

Thank you,

Michael.

 

[Twister_Ken]

No need to go back to bare ali, just sand back to a smooth finish - some might be bare, some might be previous coatings. Spray the result with International's Primocon primer, 3 coats or so, quick drying so doesn't take long, then overcoat with International's Trilux Prop-o-Dev antifoul, also quick drying. Both available in aerosols. Damn fine stuff, at least in the Solent. I also use the system on my prop, far more effective than shiny bare metal.

 

[Laurie]

+1 The primocon route has worked well for me in the past too.......

 

[aluijten]

I had a similar situation for a Volvo saildrive leg. Putting epoxy over the original paint is a bad idea. It won't stick. So I had to remove the leg the next year again and sanded it back to bare aluminum. Then I did use an etching primer followed by several coats of 2-component epoxy paint that had zinc added to the party. That seems the to the trick as I've noticed last winter. The leg looked perfectly fine last winter.

The annoying thing about the Volvo saildrives is that they use stainless bolts to bolt the upper and the lower half together. The bolt-heads are ant the underside inducing corrosion right next to the bolt-heads. They should have put some kind of insulating rings in-between, but they did not, maybe because the torque values on the bolts are too high to put plastic/fiber rings inbetween.
Because of this problem a new saildrive-leg will show corrosion at the base after a while.