Galvanized steel is often used in plumbing because of the extra durability the galvanizing process provides. Pipes are galvanized when they are dipped into a zinc coating heated to more than 800 degrees Fahrenheit. The zinc coats the metal of the pipe and provides extra protection against impact damage or corrosion. Welding a galvanized pipe is sometimes dangerous because the zinc fumes resulting from heating the pipe are toxic when inhaled. Therefore, it is often safer to remove the galvanized coating prior to welding the pipe.
Things You'll Need
- Acid-based cleaning solution
- Protective gloves, goggles and clothing
- Steel brush
Dip the pipe into an acid-based cleaning solution. Follow all instructions on the cleaning solution package regarding dilution to ensure safe handling and to prevent injury. Wear protective gloves, goggles and clothing when working with acid cleaners because they are highly corrosive. Wait at least 10 minutes to give the cleaner a chance to eat away at the zinc coating.
Scrub at the pipe with a steel brush to scrape the galvanized coating off of the pipe. The acid helps soften it, but you'll still need a lot of friction to remove the coating from the pipe exterior.
Repeat the process of dipping the pipe in the acid-based cleaner and scraping at the coating with the brush until all the coating is removed. The acid-cleaner may need occasional replenishment because it dilutes somewhat as the zinc coating bleeds into it.
Rinse the pipe thoroughly in water to rinse away any remaining traces of both the galvanized coating and the acid-cleaner so the pipe is safe to handle afterward.