Steam cleaner, West Bay Paint crew, upper deck,
San Francisco-Oakland Bay Bridge ©1971

About the Bridge Series      Inquiry

The steel sidewalls along the upper deck are steam-cleaned to remove road grime that’s been splashed on them by traffic through the years, before being given a fresh coat of paint. If the old paint itself has been damaged by vehicle contact or the elements, it will be smoothed out or removed entirely by hydroblasting with extremely high-pressure water that will remove paint without damaging the underlying steel.

Only in the most extreme circumstances, where there has possibly already been corrosion damage to the steel itself, will the decision be made to use sandblasting, which will almost certainly remove small amounts of good metal along with any rust, incrementally changing the thickness and ultimate strength of the affected steel.