Maintenance and Cleaning of Galvanized Steel

The following information provides some guidance for the general maintenance and maintenance of hot-dipped galvanized steel products from galvanized steel pipe suppliers.

Avoid exposing galvanized steel products to environments with pH values below 6 and above 12 for a long time. Outside the range of ph6-12, the galvanized layer may suffer more severe corrosion than normal.

Avoid direct contact of galvanized steel products with different metals, such as brass and copper, especially in corrosive environments. If dissimilar metals are used together, make sure there is an insulator between the dissimilar metals and the galvanized product.

Do not scrub galvanized products frequently, if possible, avoid grinding and cleaning galvanized products. One of the methods for galvanizing to protect steel from corrosion is to form a thin film of insoluble zinc corrosion products (called patina) on the outer surface of galvanized steel by exposure to the atmosphere. Abrasive cleaning will wash away this protective patina, and galvanized parts will have to build this barrier protection again, consuming more zinc. Continuous grinding and cleaning will consume zinc more quickly and therefore may shorten the life of galvanized steel products.

Galvanizing may be cleaned with water-based emulsifiers, alkaline cleaners with a pH of 12 or lower or organic solvents. Then rinse the area with clean water, and then wipe it clean with a soft cloth.

For galvanized products located in highly corrosive environments (such as coastal, heavy industry, etc.), it is recommended to rinse the products with drinking water regularly, especially under sheltered conditions (that is, not exposed to rain or sunlight).

Avoid long-term storage of any galvanized products under humid and poorly ventilated conditions. Ensure that the storage location is dry and well ventilated.

Clean Galvanized Surface

There are many ways to deal with different types of stains or marks. It is recommended that any cleaning treatment for galvanizing should be conservative first, and then if the situation demands, the treatment can become steadily more aggressive. It is also important that if some form of mechanical abrasion or "scrubbing" is required, a hard plastic bristle brush is recommended. Steel brushes must not be used because they can cause discoloration.

It should be noted that cleaning the zinc surface mechanically can cause aesthetic problems. The "clean" area may contrast with the adjacent untreated surface, and it may take a long time to make its color uniform. If aesthetics is a big issue, it is recommended to test the cleaning method in an inconspicuous place first to prevent the aesthetics from being unattractive.

For general cleaning of a large number of contaminants such as dirt, ordinary laundry soap can be used satisfactorily. For more stubborn or larger areas, using low-pressure cleaning (such as a gurney gun), just use pure water or combined with a patented cleaning material (such as a car washer or a truck washer), can be effective. The role of car and truck cleaners is to minimize corrosion to the metal parts of the vehicle, so it is usually suitable for galvanized steel, although it is important to rinse the steel with fresh water after cleaning.

Many mild stains (such as stains caused by standing and running water, or stains on beverages such as beer and wine in public areas) can be removed with ordinary household ammonia cleaners, and then make sure to rinse the galvanized parts thoroughly with fresh water.

Usually, the water discharged from other nearby rusty steel structures will flow onto the galvanized steel and cause obvious brown pollution. It can be treated with commercial oxalic acid or a special solution specially developed for descaling pots and pans. Thorough rinsing with water is also important to remove the corrosive residue of the cleaner.

Sometimes during construction or renovation, cement and mortar may fall on the galvanized steel plate. This can be very difficult to remove once it has hardened. First, remove most of the deposits as close to the surface as possible, then use oxalic acid to remove the remaining residue on the galvanized steel, and then rinse thoroughly. Other acids are more effective for mortar or cement, but these acids are very corrosive to zinc, so they are not recommended.

Paint, such as graffiti, can be removed with thinner. If some form of scraping is required, use plastic or wooden scrapers (not steel/metal objects). If the paint is wet or fresh, then ordinary thinners can be used. Once the paint has hardened, a non-alkaline stripper can be used. Likewise, flushing is very important to remove residues that may cause subsequent discoloration and/or encourage corrosion.