From their perch high above downtown Minneapolis, the clocks of City Hall have kept residents punctual for 117 years. But the passage of time has taken its toll.

The iron skeletons holding together the faces of the 22-foot-diameter timepieces, one of the city's most iconic and enduring landmarks, have rusted and deteriorated. The white panes themselves are streaked with brown rust visible from the street below.

It's why the Municipal Building Commission, a joint agency of the city and Hennepin County that runs the building, is embarking on a $1.5 million to $2 million project that will also restore the clocks' pre-1950s nighttime glow.

The county has set aside about $848,600 for the job, and the mayor allocated about $839,000 for it in his 2013 budget. That’s subject to council approval.

"We're about 330 feet off the sidewalk right now," said José Cervantes, the commission's director, during a tour Tuesday of the cavernous room that houses the clocks. "So when you get some really good winds -- 20-, 30-mile-an-hour winds -- there's a lot of [clock] face with not a lot of structural integrity."

The ride to the clock tower starts in a back room of the city clerk's office, where a cramped elevator takes passengers past six floors crammed to the brim with boxes of records up to the 12th floor. The room itself is largely empty except for a watchtower-like structure that until 2007 controlled the clocks with a gearbox that turned four long rods projecting from its walls.

Cervantes explained that along with replacing the skeleton, or "frames," workers will replace the metal panels of the face with translucent ones that can be illuminated from the inside, creating a circular backlight. That's a return to the original design, which featured glass panels. Those panels were replaced by metal ones in 1949, when the city started illuminating the hands with red neon.

Minus the rust, the daytime look will stay largely the same. "But at night, that's the beauty of it," Cervantes said. "You'll see this big, beautiful white glow with the hands on it."

The neon remains as a backup in current plans. Cervantes isn't sure whether both would be illuminated simultaneously.

The future of the neon hands, a somewhat jarring contrast to the Romanesque Revival building, is likely to spark conversation. It did during a budget hearing Wednesday, when Council Member Betsy Hodges noted that neon would have been quite foreign in the late 19th century. Plus, she added, "Does it have to be red?"

"I ... really think that there'd be a public outcry if the lighting that outlines the hands and the numbers was removed," replied Council Member Sandy Colvin Roy. "Because in many places in downtown Minneapolis, that's your clock. And it would be very difficult with just backlighting to know what time it is."

Cervantes said the cost is driven partly by the complicated logistics of moving materials in and out of the historic building, as well as the price of crafting new steel frames to hold the plates together.

The last major change to the clocks came five years ago, when each one got a GPS device to help it keep time independently as part of a $100,000 project.

Cervantes expects that if all goes according to plan, the latest project could be complete by June 2014. Given that parts of the clock faces are still held up by 19th-century pig iron, he figures it's about time.

"They did their service," he said. "They've done their work."

Eric Roper • 612-673-1732 Twitter: @StribRoper