Aluminum beam repaint. Sand in epoxy or use zinc chromate first?

[AKA-None]

Originally Posted by s/v Jedi

Since the invention of anodizing, they started using inks to color the aluminium after the electroplating and before sealing. You can make it red, blue, black etc.

Interesting I haven’t heard of that, thanks

[Cheechako]

Originally Posted by AKA-None

Kind of
Anodizing is a chemical application where you strip the metal with an acid or alkaline solution and plate via the application of electricity while the item is submerged in a chemical bath.
I did this as a job after high school and it’s very nasty stuff, not something normally done at home
Also not something you can easily touch up

I guess you are using the word "plate" liberally, but just to be clear, Anodizing is not a plating. It's the intentional creation of protective oxide layer from the aluminum itself.

[Franziska]

Just a little comment, I did use the Metapox product by Nautix as wash primer.
Seems to work, but also dissolves some of the old paint. I had few little spots where that happened, as I decided not to get all old paint off (70% are still good and adhere well, so I prefer to keep that).
So, if you use it, really apply this only to the metal/anodized areas.

I'm not going to redo it now, but I'm applying another coat of epoxy primer now....

[Pete7]

Originally Posted by s/v Jedi

About sanding epoxy in: I never did this with aluminium but did with West System on lead. Not 100% happy with it. Will try this with Interprotect 2000 next time..

Tried it on a bronze prop one year on the very strong recommendation of the local chandler. After it all fell off he gave me my money back for the remains of the 2 pack tins.

Pete