Metal-Finish Polishing/Repair
Stainless Steel
Stainless steel is low maintenance, resists corrosion and staining, and makes it an ideal base material for a host of commercial applications. Because of their corrosion-resistant quality, they do not require additional surface protection to preserve their appearance and strength.
In spite of the properties of stainless steel, its surface can be contaminated and may lead to formation of deposits, reducing its life. Surface contaminants include minute particles of iron or rust from other non-stainless steels used in nearby construction areas.
Even naturally occurring atmospheric conditions can result in corrosive deposits. Examples are salt deposits from marine conditions.
Working environments are also susceptible to warm and high humidity above indoor swimming pools. These increase the rate of corrosion, requiring more frequent maintenance.
Stainless steel needs to be cleaned for aesthetic reasons and to preserve their ability to resist corrosion. There are different methods. Steel thrives in frequent cleaning, and unlike some other materials, it is impossible to “wear out” stainless steel by excessive cleaning.
Brass
Brass is an alloy of zinc, copper and, other metals. Brass is used for decorative purposes due to its attractive gold color. Like steel, it accumulates dirt and grease deposits and is subject to tarnishing.
Brass is generally lacquered when new. This prevents tarnish when it is kept indoors. If it is kept outside, it will retain its appearance for a few years.
Most manufacturers recommend that the lacquer be removed (e.g. with paint stripper) and the items regularly polished to maintain a bright finish.
The copper in brass makes brass germicidal, via the oligo-dynamic effect (antimicrobial effect). For example, brass doorknobs disinfect themselves of bacteria within eight hours. While this is important in a hospital setting, it has other uses. Brass doorknobs therefore tend to be more sanitary than stainless or aluminum doorknobs.
Cleaning and polishing tarnished brass objects can be a real chore. Before cleaning, determine if it is solid brass or brass-plated steel. You can do this by placing a small magnet on it. If the magnet slides off, it is solid brass. If the magnet remains, it is brass-plated steel. Brass-plated steel does not tarnish as solid brass does; it rusts.
There are numerous brass polishing/cleaning products in the market. Some compounds (like ammonia based products) will react and actually dissolve the brass. Other compounds (like acidic compounds such as citric acid) will not dissolve the brass. These compounds aggressively attack the compounds on brass. The mild acids soften the compounds, making removal easy. The partially oxidized brass remains. You can polish this with minimal effort.
If brass is tarnished, restoring its original appearance can be a difficult process. It involves a two-step process.
- Remove light tarnish with simple liquids that react quickly with the oxidized brass.
- Once brass regains its natural shine, dust and wipe it regularly.
