The Liberty Bell has received a coating of protective wax from conservators. It’s applied once or twice a year to the inside of the 2,080-pound iconic bell.
The outside of the bell has been given a variety of coatings over the decades. The inside of the bell is a different matter.
Years ago, the National Park Service discovered there was a buildup of ammonium sulfate powder in the bell’s interior. The theory is that airborne pollution causes the buildup when it gets trapped in the stagnant air inside.
On Thursday, experts removed the previous protective coating and applied a new one. Park Service curator Bob Giannini says the process takes a half hour or so.