Contractors at Fort Mackinac Testing Repair Techniques
By Sean Ely

Eddie Murray (left), Doug Armstrong, and Bill West at Fort Mackinac Monday, June 25, while putting the finishing touches on one of the walls near the North Sally Port. "The company is doing repairs and testing new products to see what will work the best for Fort Mackinac in the long run," said Phil Porter, director of Mackinac State Historic Parks. "They have done standard restorations and basic masonry restorations. They took the old stones off, and put new ones on. They took the lead out and remasoned it, and remortared it into place. When they put the joints in, they use a limestone caulk, which will be more weatherproof."

About five years ago, Christman Company, a general contractor from the Lansing area, and its sublet contractor, Schiffer Mason Contractors, Inc. of Holt, repaired the crumbling walls of Fort Mackinac, but since then, those walls have shown serious signs of deterioration.

The Michigan legislature appropriated $4.2 million to the repair and restoration project, which was conducted from 1999 to 2002.

Now, Schiffer Mason Contractors are back to fix three major walls near the North Sally Port because they have not withstood weather damage. The companies have agreed to fix the problem, free of charge.

"The company is doing repairs and testing new products to see what will work the best for Fort Mackinac in the long run," said Phil Porter, director of Mackinac State Historic Parks. "They have done standard restorations and basic masonry restorations," he said of the recent work. "They took the old stones off and put new ones on. They took the lead out and re-masoned it and remortared it into place. When they put the joints in, they use a limestone caulk, which will be more weatherproof."

Moisture seems to be the most significant problem with the walls at Fort Mackinac, which were built 226 years ago by British soldiers when they moved the fort from the mainland during the Revolutionary War.

"Were looking for a way to seal the walls up better," Mr. Porter said. "Moisture disintegrates the mortar and it sometimes leaches in and begins to disintegrate the lead. Whatever way it is happening, we know that water is getting into these walls, so that's what were really trying to deal with."

The company is using a new limestone caulk, specifically designed for masonry applications. Their purpose for using the limestone caulk rather than masonry caulk is because of the limestone's flexibility. The joints will not crack, and it is more waterproof.

They will also be using a product called Acromax, which is a combination of thin fabric and fluid coating that is wrapped around the top of the wall to keep moisture from getting in. Tuck-pointing the weak mortar joints will also incorporate Acromax.

"Its great because well have it over the lead removed area, where we still have lead, where we have completely rebuilt them, and where we have just repointed them," said Mr. Porter. "It gives us a lot of different comparisons so that we can see how we can move forward from here."

There are three sections that are being worked on by the contractors over a 10 day period, all of them on the north end of the Fort. The various repairs will be monitored over the next five years, and whichever tactic works best will be used in future wall restoration projects.

Doug Armstrong, Bill West, and Eddie Murray were three of the masons from Schiffer Mason Contractors, Inc., that were working on the final wall Monday, June 25.

"Everything's been great so far," Mr. Armstrong said. "Well be done here this week."

Once the contractors leave the Island, its a waiting game. Monitoring the progress of these applications is crucial.

"This is really interesting for us because we can experiment and watch the walls over the years and see what works in the best way and apply that as we work on the rest of the walls as they deteriorate over time, which they will do, because they've been doing it since they were built," Mr. Porter said.