Читать книгу Welding For Dummies - Steven Robert Farnsworth - Страница 35

Chemical cleaning is, as you can probably guess, a way to clean steel by using harsh chemicals. I’m talking about some pretty rough chemicals here, so if you go the chemical cleaning route, please be sure to treat the materials with the utmost respect.

FIGURE 2-3: Cleaning steel with an angle grinder.

The chemicals used to clean steel before welding are caustic and extremely dangerous. They can do serious damage to your eyes and skin. Before using any of these chemicals, be sure you’ve read and understand the Material Safety Data Sheets (MSDS) that lay out their risks. Pay special attention to the ways in which you combine these chemicals because many of them react violently if you mix them up.

You can clean steel with several different chemicals, and here are a few that you may want to consider.

Almost all the solvents used to clean steel and other metals before welding are extremely flammable, so be sure that no spark or flame ever comes in contact with the solvent or its fumes. If you clean steel with one of these solvents, make sure the metal is completely dry and the solvent has evaporated or dissipated before you begin welding. Also, be sure to keep your solvent containers in a safe place away from your welding area, as I note in Chapter 3.

 Acetone: This harsh chemical removes rust and oxidation from steel. Welders usually use acetone by spraying it on and rubbing or wiping it off with a clean rag. Compared to some of the other solvents sometimes used to clean metal, acetone is relatively mild, but it’s still a toxic material, so proceed with caution.

 Alcohol: You can use alcohol for light cleaning and for degreasing. I recommend spraying it on and wiping it off with a clean rag or cloth.

 Acid: You can use sulfuric or hydrochloric acids to remove rust scales and oxidation from steel before welding it. These substances are dangerous, so use extreme caution if you go this route — in fact, I recommend cleaning with acid only as a last resort. After applying the acid, make sure you rinse the area thoroughly with hot water and dry it as soon as possible.