Where the world gathers for
plating, anodizing, & finishing Q&As since 1989

"Pre-weathering of galvanized roofing"

-----

2003

What is the best method to use to accelerate the "weathering" of galvanized metal roofing to achieve the attractive, dull zinc- grey look that the metal attains when left to weather naturally outside? I want to use it for an interior ceiling finish. I have been told that a vinegar solution will remove the oil coating of the new metal and speed up the weathering. Anything else that would work faster or better?

Ralph A. Thibodeau
- Spicewood, Texas

---

2003

Vinegar (acetic acid) will not remove oil, but it will etch the zinc which is probably what you want. You need to make sure that there is no oil or other organic coating on it before you etch. Rinse very well after etch or you will get a very mottled finish. Try a few test panels befor you jump right into it. Remember, the test panels are small, so will look better than the large panels.

James Watts
- Navarre, Florida