It's time for Billy Penn's once-a-decade makeover

Workmen install scaffolding around the statue of William Penn atop City Hall on Tuesday May 10, 2017, in preparation for restoration of the 125-year-old statue. The 37-foot-tall statue's last conservation treatment was in 2007.

William Penn is getting a makeover.

It is time for the 37-foot tall bronze statue of the founder of Pennsylvania sitting high atop City Hall to get the sculpture version of a spa day treatment with a bath, a laser treatment, wax and buff.

But this treatment will take more than a day. Think four weeks to six weeks, weather permitting.

It has been 10 years since the sculpture's last conservation treatment. Prior to that, it underwent makeovers in 1987 and 1996, according to the Office of Arts, Culture and the Creative Economy.

The statue, created in 1892 by the sculptor Alexander Milne Calder, is fitted together in 47 sections with 1,402 bolts, located 500 feet above the street, and weighs more than 53,000 pounds. It is the largest sculpture atop any building in the world.

The conservation project had been scheduled for the fall but encountered some administrative delays. It also was postponed until after the NFL Draft so scaffolding would not interfere with video and photos of the City Hall, said Margot Berg, the city's public art director.

And there were weather issues.

"It is really weather dependent," Berg said. "You can't do it when it is too cold or too hot." 

The installation of the scaffolding needed for the project should be completed on Wednesday, Berg said. After that, crews from Moorland Studios of Stockton, N.J., will begin the process.

A low-pressure water treatment and specialized soap and brushes will be used to remove the dirt and corrosion and address damage caused by atmospheric pollutants, winds, and — of course —  bird poop, Berg said.

The surface of the statue has tiny pits that were caused by the casting at the foundry, Tacony Iron Works, Berg said. 

"We use a laser to remove the corrosion from those pitted areas," she said.

A protective layer of wax will be applied and buffed to make sure there is an even coating, she said.

The statue is one of the city's most recognizable and cherished assets and its conservation treatment is always historic, said Berg.

Her office is responsible for the care of more than 1000 sculptures, reliefs, mosaics, stained glass pieces, kinetic works, paintings, and murals.

Funding for this project is provided by private funds, city capital dollars and a $25,000 grant from the National Endowment for the Arts, according to the office.