Upper part of rudder

[dontpanic]

The upper part of the rudder ( not the blade) on my ComPac 16 (aluminum, I believe) is coated with what appears to be surface corrosion.  I am planning to wire brush this part and paint with black rustoleum primer and finish.  I don't think there are any structural issues, just an appearance issue.

Does this sound like a good plan?

Thanks

[MacGyver]

My opinion, Wire brush or sand, and then wipe down to clear the dust, then use a Etching primer, followed by your choice of color.

Aluminum is a hard metal to adhere paint too and have it stick.
The primer has acid in it that etches the surface and primes it.

Mac

[Banana Cakes]

I sanded it down with sandpaper and worked like a charm! I used 80-grit 120-grit then 320'ish-grit.  When I used the primer spray paint, I made MANY coats as MacGyver said, be patient! It isn't graffiti, but to do it right takes time and once there is a consistent layer of primer you are all set for the finishing coat! Good luck and can't wait to see the final product!

[skip1930]

Salt water or fresh water?

Wire brush the 'white fuzz' off the aluminum casting and sand down to clean white metal. Basically scratch down to 'good aluminum'.
We at Palmer Johnson Yachts grind 104 tons/150 foot of aluminum plate down to clean ground metal.

Side Bar: P.J. Yachts made a 102 foot sailboat hull and that was cancelled because the owner wanted a larger hull, so there it sat outdoors for years.
Now the aluminum is too far gone and will eventually be plasma-ed apart and scrapped BECAUSE "we don't have enough Mexicans to grind her back to white metal."
That's the company joke friends. All of our 'putting a fair line into the hull' is done by our all Mexican crew of about 40 hard working men. Can't build a boat with out them.

Now, wash the oils and soils off of the rudder's substrate so the conversion and etching chemicals can 'see' the metal. These are water based and will float on oils and soils. So cleanliness is a must. Dry.

At Ace Hardware is a product that is an aluminum conversion coat, Navel Jelly for aluminum. Follow the bottle's directions.

Than as MacGyver says an etching primer [I don't think it's an acid, [lower pH but rather an alkaline, higher pH]. Doesn't matter.

Once the layer of etch has dried ... laid down a layer of any paint you like. Nothing wrong with Rustoleum primer and Rustoleum color top coat. Mil build of dried coating is the key to longevity. So plan on several layers of prime and paint. Try to use a paint that is a Poly-Ester for maximum UV protection to limit chalking.

I powder coated and baked mine with a hammer tone grey paint after it went through a 9 stage spray washer.

skip.

Needs to be ground 'clean' to white metal.


Needs to be ground 'clean' so the aluminum conversion yellow etch primer [below] can be applied before the pink ALL GRIP bondo.




The pink All Grip bondo is sanded to the shape of the ship's fair line.


It cost $1.2 million to paint a 150 foot yacht. I think this is Tiger Woods boat. Now up for sale. Typically P.J. LLC, Sturgeon Bay bids the contract for a 150 footer at around $18 million to P.J. World who then sells the boat for around $44 million.

This is a P.J. fiberglass yacht. Amazingly it is all clear span inside the deck house. [Unlike aluminum boats, there is always a vertical in the way of something.] Talk about a ballroom. This boat was made for a fellow who owns a pro basketball team and so all the doors were made 12 inches taller than normal.
It is made up of honeycomb fiberglass squares basically glued together. Heavier then aluminum of similar size.  
See? Wealth does trickle down.

[nies]

FYI.................have old 12 foot Aluminum boat, having layed upside down for a year the bottom had black mold/greenish slim, was cleaning something else with 409 Cleaner and decided to try on boat bottom and use scrub brush..........................worked great and looks like new, told the guy at the marine and he said thats what they  use......................nies

[dontpanic]

Thanks for the great replies.  I'm also glad that I was reminded that I have a 12' aluminum boat that has been sitting upside down for years.  Sounds like I need to paint it as well.