Painting Anodized Aluminum

[chrysanthemum]

Dear Cruising Community. We have gold colored anodized mast and booms on our 1974 ketch that are tired and need painting. The general surface is pretty good but there are some areas where the anodizing has disappeared and the aluminum is visible. Does anybody have any ideas of the best paint system to use and in particular the best primer? I would love to do the job by hand if I can and avoid using spray guns. Also we had our hull painted about six years ago using Awlgrip and a spray gun system with a big tank. The result was very good but it is time to paint it again. I would love to be able to do this by hand as well. Does anybody have advice on the best way to go about this and get a half decent result? The present surface is really pretty good there is just some discoloration and staining. The six year old surface is intact. Is there some modern system that will allow us to get a decent enough result by hand? - with so much thanks

[leboyd]

This isn't painting a boat, but does a great (and funny) job of explaining how to paint aluminum.

https://www.youtube.com/watch?v=gIhgyNaKKiQ&t=4s

[roverhi]

The last thing I'd do is paint an anodized mast. The prep. work is extensive and unforgiving to marginal job if you want it to last any time at all. Once painted you are condemned to keeping up the paint which is not all that easy to do.

The paint video above leaves a lot of things out of successfully painting aluminum if you expect it to last any time at all in a marine environment. Aluminum paint sytems require an etching wash after doing all the pre paint prep work that he outlines. Then you need an aluminum specific primer like zinc chromate or whatever your paint system reccomends. Last is the top coat which should be a two part Polyurethane paint for longevity. The aluminum should be primed as soon as the etching wash step allows. Aluminum begins to oxidize when exposed to air. That oxide coating prevents proper primer/paint adhesion. Get the primer on asap or you risk the paint coming off in sheets.

[model 10]

I would touch up the anodizing with Alodine. Not as good of course, but necessary even if you were to paint so maybe it would look OK to you. It can have a golden color or clear.
A brush or roller paint job is tough to pull off well, but people do it all the time.

[Pete7]

I have never really managed to get paint to stick to my Ali dive cylinders despite lots of effort. Can't see a mst being much different. How about vinyl wrapping it in plastic just as they do cars and boat hulls?

Pete