Happy hundredth birthday, Grand Central Terminal.
You might not remember us from here in the nation’s heartland. But in 1980, when you were a mere 67 years old, our crew here at PROSOCO in Kansas helped to give you your first-ever exterior cleaning. You needed it too. Sixty seven years in the industrial Northeast, amid the coal-burning factories, and later, the automotive traffic, did a job on your beautiful cream-colored limestone.
Horn Waterproofing Corporation, Long Island, was set to do the actual cleaning. But nothing’s ever that simple. You see, after 67 years, all that black carbon soiling hadn’t just piled up on your walls — up to three-quarters of an inch thick in places, according to PROSOCO Vice President John Bourne who was there and remembers you well — it had sunk into your stone fabric.
That’s the difference between soiling and staining. Soiling stays on the stone. Staining comes from contaminants that have soaked in over the decades.
Horn Waterproofing could’ve blasted it off with high-pressure water and harsh chemicals. Unfortunately, that would’ve damaged your limestone walls, and all the beautiful carved ornamentation on your upper reaches. So the architect, Hardy-Holtzman and Pfeiffer asked PROSOCO for input on cleaning methods and materials.
After several months and 28 field tests, PROSOCO developed the way to get you clean.
It wasn’t easy. John remembers how they did a handful of cleaning tests, all of which turned out beautifully — until 24 hours later, when brown stains developed in the middle of the cleaned test panels.
Gerry Boyer, the son of PROSOCO’s founder Al Boyer, and father of PROSOCO’s current President David Boyer, came out to have a look. Gerry is one of the nation’s pioneers of restoration cleaning.
The diagnosis was an inadequate rinsing of cleaning residues from the stone. In addition, alkalinity from the non-acidic cleaner required better neutralization.
To fix it, Gerry worked with the company’s laboratory crew to retool PROSOCO’s limestone cleaner. They made it thinner, so it could rinse off more easily, as well as go in after the staining more effectively. They made it less alkaline so it could stay on the stone longer, and use a less aggressive acidic neutralizing agent.
Sure Klean T-556, made just for you, Grand Central, worked so well that it became the starting point for creating the most advanced system ever for cleaning limestone buildings — Sure Klean 766 Limestone PreWash and Sure Klean Limestone & Masonry Afterwash.
Many an historic building has profited, Grand Central, thanks to what you taught PROSOCO about cleaning limestone.
Getting all the different groups involved to agree on exactly how clean you should be was almost as hard as figuring how to clean you, John recalls. Some believed a light patina of atmospheric staining belonged on you as part of your history.
There was the architect, the NYC Landmarks Commission, the Municipal Art Society, the Historical Society, the railroad — even Donald Trump was involved. It’s not commonly known, John says, but Donald donated the money to do the cleaning.
John and Gerry met Donald during the project, but only briefly. Jacqueline Kennedy Onassis, who was actively involved with the Municipal Art Society also visited you, Grand Central. But the paths of John, Gerry and Jackie never crossed.
All the groups eventually agreed you should be cleaned to reflect the vision of your original 1913 design team, headed by Alfred T. Fellheimer, which is to say — as clean as they could get you.
Restoration cleaning takes a lot of water. You have to soak the surface down before applying the cleaner. After the cleaner has done its job of breaking the bond between soiling, staining and stone, you rinse it all away with more water.
So it didn’t help that the city had a water-shortage that year, and the water to pre-wet and rinse you had to be trucked in.
Along with the cleaner developed specially for you, Grand Central, Gerry and John also came up with a special way to pre-wet and rinse you to ensure no harm to your historic limestone exterior and ornaments. Soaker hoses wetted your stone for three to four hours at a time for a thorough but gentler pre-wetting than the usual pressure-wash.
They found specialized high-pressure steam jennies generating a relatively gentle 350 psi, but putting out 3-4 gallons of water per minute in steam, compared to the standard one-gallon. It’s the amount of water that dictates the effectiveness of the rinse, not the psi — another fact that’s not commonly known.
In the end, all the time, trouble and tests paid off. Using PROSOCO’s product and procedures, Horn Waterproofing safely stripped away the clinging black mantle. The work restored you to the beautiful and iconic Beaux Arts palace you were always meant to be.
With an end to coal-burning factories, and cleaner auto-emissions, that awful black coating hasn’t recurred.
Since then PROSOCO has returned for occasional exterior spot cleanings and work on your splendid interior marble walls, though nothing as dramatic as that original 1980 project.
Happy birthday, Grand Central Terminal — 100 years old tomorrow. What could be grander than that? And should you ever need us again during your next hundred years, PROSOCO will be there.
In honor of Grand Central Terminal’s 100th birthday, the Metro Transit Authority/Metro North Railway shares these terrific glimpses of the iconic building.
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