Acid cleaning is a process used to remove various types of discoloration and tarnish from metals or masonry. This type of cleaning method is commonly employed to keep brick walls, concrete sidewalks, and metal storage buildings clean and looking new. Some forms of this type of cleaning also take place in the home as a means of removing tarnish or hard water stains from various surfaces. Depending on the material to be cleaned, and the type of stains that are present, the cleaning acid employed may be strong or mild.
The exact methods of acid cleaning will vary, depending on the situation. Objects such as metal pans can be soaked in a combination of water and some type of acid cleaner to remove food stains. When cleaning walls or walkways, the approach usually involves utilizing a constant stream of water as part of the washing process. It is also possible to coat the surface with a cleaning agent, allow it to set for a short time, then scrub the surface in order to remove the tarnish or stain.
Mild acid cleaners are often used to handle household cleaning tasks. Acetic acid and citric acid are found in many of the common cleaning agents designed to dissolve hard water spots on shower walls and doors, as well as to remove rust stains from porcelain. Similar products that contain cream of tartar can be used to clean brass and copper pots, candlesticks, and other accessories with relative ease.
Strong acid cleaners are used when the tarnish or stain is more resistant. These compounds usually contain muriatic acid, sulfuric acid, sodium bisulfate, or some combination of the three. Acid cleaning products of this type are effective when washing down concrete, acid cleaning aluminum or brick, or dealing with tough stains in a toilet bowl. Depending on the amount of dilution that takes place with the acid, it may be necessary to apply the product more than once to completely clean the area.
With any type of acid cleaning project, it is important to protect the body from contact with the acid product itself. This can mean wearing protective gloves, and possibly taking the time to use protective goggles over the eyes. Because some products can bleach out fabrics, it is generally a good idea to wear old clothes while handling the cleaning task. If working with the acid in an enclosed area, it is often a good idea to make use of a face mask as well, to prevent the inhalation of fumes. While most acids are safe to use with proper precautions, failure to use adequate protection can cause physical discomfort for the eyes and skin.