I am a new owner and I just had my vessel waxed (73 aluminum 60') and I have a couple of places that look like rust is coming through the paint. One is on the deck in front of the windlass (see attached JPG file named "Rust_Pic.jpg) and the other is the upper deck salon roof area. How is this possible?
Sherlock Holmes Watson - What facts do we know about the oxymoronic case of "The Mysteriously Rusting Aluminum"?: 1. Aluminum simply doesnt "rust" - its surface layer oxides and quickly forms a self-protecting patina (pink) whereas steel/iron forms an oxide which flakes off exposing more metal to attack (red). 2. Now, we know corrosion often results from salts and contaminants which may have leached into the aluminum (oxide) surface - possibly during paint prep. 3. Similarly, iron, copper or steel contaminants (steel wool filings or somebody's idea of non-skid perhaps?) may have gotten into the paint only to be exposed later (much to boat owner's chagrin). 4. Finally, and most unlikely - red mercury is at work: The Amazing Rusting Aluminum | Popular Science *WARNING: Keep this a secret.** BOTTOMLINE: Try re-coating those areas (thick enuff to prevent contact with oxygen) and see if that solves the problem.
It looks like steel fragments have gotten on, into the paint. Do you have galvanized anchor chain and was the windless used recently? Has it been around a boatyard where they've been grinding on steel? It could've fallen into the fairing material prior to painting, but it looks like it's from fallout. Carefully put a little whink on it and see if it dissolves it.....
This looks like classic case of steel shavings from cutting or drilling into stainless steel and not cleaning it up thoroughly. The dust will rust very quickly and stain the surface Spraying rust stain remover will take care of it
Galvanized chain may rust and leave a stain but the little grains are signs of either cutting, grinding or drilling
(Bad) Genie Does it contain Hydrofluoric acid? Just a bit (Hydrogen Fluoride -1.50 – 3.5%), and some Denatonium Benzoate (0.01 – 0.10%), SO? http://www.wardrobesupplies.com/ass...ts/Whink Rust Remover 10062008.pdf?1323898750 "Very toxic by inhalation, in contact with skin and if swallowed. Causes severe burns. Inhalation of vapors in high concentration may cause shortness of breath (lung edema). Ingestion causes burns of the upper digestive and respiratory tracts. Will penetrate skin and attack underlying tissues and bone." Oh dear. Careful! -E