Etching stainless steel is done for a variety of reasons including the creation of prints, decorations and personalization. The etching process is the result of a chemical reaction that removes a layer of steel in the exposed area of a chemically coated steel plate.
What It Is
Metal is etched through the use of a mordant, or acid solution, which eats the metal away in places where it is not protected by a chemical resistant to the mordant's chemical reaction. The traditional steel etching process has been too toxic to perform outside of a very controlled environment.
Early Etching Methods
Early methods of etching steel involved a recipe of various high strength acids. Other formulas involved mixing nitric acid and muriatic acid together. The steel to be etched was covered in asphaltum that resisted the chemical process. The places where the asphaltum was scraped away or not present were the areas the mordant would eat away. These early methods often put off a lot of vapor and were highly toxic.
New Etching Methods
In recent years, a new method evolved out of the necessity to create non-toxic printmaking methods that would not cause an artist severe health problems. These methods are also much better for the environment and are executed in a way that does not require a lot of specialized equipment for its disposal.
Saline Sulfate Etching
Saline sulfate etching involves the use of two readily available compounds, copper sulfate and table salt. Mix equal parts of each compound together in hot water to yield a mordant that works well on stainless steel without any hazardous byproducts or harmful vapors. The etching quality from the use of the saline etch is very crisp and fine. This method can be used to etch aluminum and zinc as well. When stainless steel is etched with the saline sulfate, there is orange-colored residual material which will easily break free from the metal. This material is corroded metal and can be carefully cleaned away if a deeper etch is needed. Stainless steel is rust-resistant but not rust-proof, so dry the etched steel immediately after etching to prevent rusting. Etching steel is no longer a toxic process. The advent of a non-toxic method ensures inexperienced artists an easy method of etching stainless steel.
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