A lesson on granite protection from the Gettysburg Memorial
There may not be more hallowed American soil than that of the 4,000 acre Gettysburg National Military Park. Millions come every year to see for themselves the ground on which 51,000 Confederate and Union soldiers gave their lives just over 150 years ago.
Today’s observers will note, however, that the park offers not just a historical lesson, but a lesson on surface cleaning and protection.
The Gettysburg Monuments
An event of such scale and significance as the battle of Gettysburg requires a fittingly grand memorial. This was, after all, not only one of the bloodiest battles of the Civil War, but also one of its turning points.
As a result, today there stands a total of 1,328 monuments, according to the National Trust for Historic Presentation, ranging from equestrian bronzes and regimental monuments to smaller markers – along with the more than 400 cannons and other objects scattered throughout the park.
The monuments are a testament to the hardiness of granite. Made from the now-near-impossible-to-get-hold-of fine-flecked Westerly Rhode Island granite, the material was originally chosen over surfaces like marble, limestone and sandstone, which were considered too vulnerable, despite their beauty. Sure enough, many of these monuments have since stood the test of time, reminding millions of Americans about their forebears’ sacrifices.
Keeping the memorial clean and spotless
Nonetheless, even granite is not impermeable to the effects of time and weather. That’s why the park has a dedicated preservation team which works to keep the monuments as spotless as possible, comprised of three full-time staff and three seasonal workers.
Some of the damage the team has to contend with is your run-of-the-mill vandalism, which has toppled statues over. There’s little that can be done to prevent such damage, unfortunately.
Other types of damage are less calculated, and require careful surface cleaning on the granite. Many of the statutes have corrosion, which needs to be cleaned off. There was also the frequent problem of acid rain.
Acid rain – the menace of stone
Acid rain has been one of the most damaging phenomena for the park’s granite monuments. As of 1989, Pennsylvania,where the park was located, received more acid rain than almost any other state.
This was owing to the large amount of coal-powered plants in the regions in and around Pennsylvania – coal-burning creates smoke that contains sulfur dioxide, a key ingredient in acid rain.
According to the Environmental Protection Agency: “Acid rain occurs when these gases react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds.” Winds can blow these compounds across state lines.
Unfortunately, the combination of large amounts of acid rain and large amounts of statues, coupled with a lack of maintenance of the memorials, took its toll on the works. It wasn’t unusual to see headlines declaring that the statues were “melting”, or being “washed away” and conquered by the effects of acid rain.
The effect is known as acid etching – when acidic substances eat away at a particular surface, slowly corroding it over time. It can do anything from simply tarnishing the appearance of a stone material to weakening its entire structure.
This is what made the choice of granite, a non-acid-sensitive stone, as a material so important. Late in the 19th century, the Gettysburg Battlefield Monument Association established building guidelines for all future monuments, one being that they be made from granite from then on, rather than the more acid-sensitive limestone or marble.
Owing to this decision, it is the granite monuments which have fared the best over time.
Combating damage through granite protection
The preservation team worked to offset all of the various forms of damage to the Gettysburg memorial. This involved both cleaning the monuments and, when necessary, replacing whole parts of the statutes. Today, the team aims to preserve them on an approximate three year basis.
You don’t have to have a budget of hundreds of thousands of dollars to keep your own granite looking pristine, however. It can be as simple as making use of Dry-Treat’s surface protection and cleaning products.
Whether water or other liquids, META CRÈME™ can seal stone against penetration by these substances. Meanwhile, if it’s stains you’re hoping to get out of your granite surface, the heavy-duty cleaner HANAFINN Oxy-Klenza™ can make quick work of it.
With the right effort, perhaps your granite will be able to reach its own 150th anniversary somewhere down the line!
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