Bradley Jesness wrote:

"muskrat" wrote in
roups.com:

One of the great lessons about owning a boat is the power of
nature to thwart humans' efforts to build stuff that lasts -
stainless steel stains, plastics of all kinds succumb to solar
radiation, aluminum rusts, etc.

So time has come to polish up my flying bridge, about 100 feet
of two inch aluminum tubing. I don't want to start any fights,
but what do you all recommend?

Stainless steel or any steel or iron rusts. Rust is iron oxide.

Aluminum corrodes (aluminum oxide). Aluminum reacts with air to grow
its own thin oxide coating very fast. This hard, dark gray coating
protects the metal. It's found on all bare aluminum surfaces. If
washed off, it quickly forms again..

If you actually have rust on your aluminum, it must be from iron
because that is the definition of rust.

We have our radar arch powder coated, which is a paint powder that is
baked on thus melting the powder into an even finish.

Anodizing is a coat applied with electricity instead of heat. The
metal can also be lacquered or waxed to protect aluminum against
weathering and corrosion.

Use a white tissue to wipe the aluminum surface in a spot 6 to 10 times then check the tissue and the surface. If the tissue turn to black and that wiped aluminum surface changed color then you will know this is not an anodized aluminum. If the surface has oily look then you will know that is waxed.

Remove stains from aluminum with silver polish, or mild, nonabrasive
cleaner or brighten it (remove the oxide) with a *mild* acid. But it
the protective coating will form right away again. Do not clean
aluminum when it is too hot to touch, or if temperatures go below 50
F.

The Architectural Aluminum Manufacturers Association, recognizing the
need for the aluminum industry to provide information on the care and
maintenance of exterior wall finishes (which are in a lot of buildings
- there are even companies which specialize in cleaning anodized
aluminum finishes in buildings), released a publication entitled
“Voluntary Guide Specification for Cleaning and Maintenance of
Architectural Anodized Aluminum, AAMA 609.1-1977.” This specification
outlines methods, equipment, and materials to clean anodized aluminum

For light soils, the simplest procedure is to flush the surface with water using moderate pressure. If soil is still present after air-drying the surface, scrubbing with a brush or sponge and concurrent spraying with water should be tried. If soils still adhere, than a mild detergent cleaner should be used with brushing or sponging. Washing should be done with uniform pressure, first horizontally then vertically. Following the washing the surfaces must be thoroughly rinsed by spraying with clean water.

Probably it is better to use a plastic pad or sponge because the steel
wool pads can leave behind bits of steel which will rust.

If it is necessary to remove oil, wax, polish, or other similar materials, MEK or an equivalent solvent is recommended for clean up. Extreme care must be exercised when solvents of this type are used since they may damage organic sealants, gaskets and finishes. These solvents should never be used on anodic finishes protected by clear organic coatings unless the organic coating has deteriorated and should be removed.

Aggressive alkaline or acid cleaners must never be used. Cleaning hot, sun-heated surfaces should be avoided since possible chemical reactions will be highly accelerated and cleaning non-uniformity could occur. Strong organic solvents, while not affecting anodized aluminum, may extract stain-producing chemicals from sealants and may affect the function of the sealants. Strong cleaners should not be used on window glass and other components where it is possible for the cleaner to come in contact with the aluminum. Excessive abrasive rubbing should not be used since it could damage the finish.

A wipe-on surface protectant is now available which is estimated to provide protection for 12 to 24 months in the harshest environments. This protectant is applied to a thoroughly cleaned and dried anodized surface with a lint-free cloth or felt pad. The benefits of such an application are two-fold; first, it protects the finish, and second, it makes subsequent maintenance easier. Subsequent maintenance may well be reduced to simply flushing the surface with water, permitting it to dry and wiping on a surface protectant every few years. In applying this protectant it is very important that the manufacturer's recommendations be carefully followed.

Equipment and products needed for cleaning and maintaining anodized aluminum finishes are listed in Section 7 of AAMA 609.1-1977. These include mild soaps, detergents, non-etching cleaners, abrasive cleaning pads and cleaning machines. AAMA, however, has not evaluated these materials nor does its listing constitute an endorsement. This list is included only as an aid to potential users in identifying the materials


grandma Rosalie