Mackinac Bridge Painters Use New Methods
Crews painting the north span of the Mackinac Bridge this year are using a combination of scaffolding and the safe-span system as a work platform, a work method never seen before on the five-mile suspension bridge.
With equipment decked out in red, Abhe and Svoboda, Inc., from Prior Lake, Minnesota, with a Michigan office in Gaines, has been sandblasting and painting the bridge since May, although workers started setting up rigging to work from last August.
To form the containment area where workers sandblast and paint the metal, scaffolding runs down the side of the bridge to sheets of roofing steel held up by a series of wires suspended over the water. From this platform, workers use high-pressure sandblasting and painting equipment to strip down the old coat and repaint every inch of the bridge.
Owing to environmental restrictions, crews are required to remove the sand and paint reside from this containment area using a huge vacuum system. The sandblasting, paint spraying, and vacuuming equipment sits atop the bridge surfaces on the anchor piers, pumping clean sand and paint hundreds of feet to workers below and then vacuuming any residue back to towering storage tanks.
From the work platform, workers shoot blast sand, called Black Beauty and brought up from Gary, Indiana, stripping down the surface before painters arrive. Three coats of paint are then used in repainting the bridge: A zinc primer coat, epoxy intermediate coat, and urethane final coat, the deep green color motorists have come to associate with the northern Michigan landmark.
The safe-span deck system, combined with the scaffolding, is a safer and better platform to work from than harness-based systems, said project supervisor Leon Wagner, who has been painting bridges for 30 years.
"It gives us better access and allows us to do more of a quality job," Mr. Wagner said. "It's safer all around."
Each morning, about 35 workers arrive at the job headquarters across from the golf course on US-2 and are ferried onto the bridge aboard a bright-red school bus. At the end of the day, they head back on the bus, shower in the decontamination trailer, and change into clean clothes before punching out for the day.
The bus isn't the only thing on the bridge sticking out like a red thumb. All of the equipment owned by Abhe and Svoboda sports the color, something Mr. Wagner said was just a simple choice.
"Our equipment was looking kind of drab," he said. "We just wanted to paint it, and red was the color."
He had seen a semi-truck painted the same color while working on a job in Oregon, Mr. Wagner said, and decided it would look nice covering all of the bridge painting equipment.
The bus being used to transport workers was originally a more traditional yellow, but Michigan State Police from the St. Ignace post informed the company that state law dictates that only school buses be painted yellow. A few cans of red paint later, the crew had a new red ride.
Most of the workers are staying either in St. Ignace or in Sault Ste. Marie, Mr. Wagner said. There is a mixed group of workers on the project, hailing from Sault Ste. Marie, Port Huron, St. Ignace, and a few from farther away.
The crew is behind schedule, and part of this may be because the enclosure the company is using may not be the most efficient way to go, said Bob Sweeney, executive secretary for the Mackinac Bridge Authority.
"The jury is still out on whether or not it's the best method," Mr. Sweeney said. "We're extremely happy with the quality of the work, just the speed of the work is slower than what we contracted for."
"The bridge is actually in pretty tough shape," Mr. Wagner said. "It takes more time to blast."
He attributes much of this deterioration to the salt used to melt snow and ice on Michigan roads. Long winters in the region mean road salting starts early and ends late, he said, which gets picked up by cars, carried out onto the bridge, and can be dropped through the grating in the center lanes. Salt is not used on the bridge itself, although it can be brought by cars from other roadways.
The salt, combined with the moisture that comes from a structure being suspended over water, eats away at the paint and metal and causes problems sooner than would occur elsewhere, Mr. Wagner said.
The project was planned to be finished in October, although Mr. Wagner said he doesn't expect them to meet that deadline. Paint can only be applied if temperatures are steadily above 50, he said, and the crew will likely need to return next year to finish the painting contract.
"This year, the temperatures have been a real challenge," he said.
Tuesday, August 11, crews had to wait until 10 a.m. to start work because of low morning temperatures.
To help move things along, the workers plan to switch to a threecontainment area system where one area will used to set up rigging for future work, one area will be for sandblasting, and the final area will be used by the painters.
"It should help us get things done a little more quickly," Mr. Wagner said.
The lifespan of the paint being used on this project is estimated at 25 years, although with continual maintenance, Mr. Sweeney said they expect it to last closer to 35 years. In two years, Abhe and Svoboda is required, under warranty, to return, inspect the bridge, and touch up any spots that have deteriorated or that weren't adequately covered in the first place.
Crews from the Mackinac Bridge Authority will then do their own touch-ups to the painting about every five years.
This sort of touch-up work is currently being done on the south span by Bridge Authority workers, since the company that painted the span defaulted on its warranty. A lawsuit is currently pending with All-State Painting to recoup losses incurred by the bridge authority by doing the warranty work with its own crews.
American Painting, which completed painting of the center span in a joint venture with All-State, has agreed to complete the warranty work on the center span itself.