One of the world's largest Princeton, NJ-based pharmaceutical companies was disgusted by an unsightly black substance leeching down off the parapets of their 1.5 million square foot limestone office complex. This substance left behind a permanent black stain all along the upper portions of the building façade, and had been accumulating over the past decade. Since these buildings comprised the World Headquarters for this company, it was important for them to "sparkle" once again. This complex hosted VIP's from all over the world, and this company was no longer willing to let this "dirty" image become the first (and last) impression for visitors and employees alike.
As the project team set out to figure out the solution, they quickly realized this was no small task, as the company sits on a nature preserve and the Environmental Health and Safety (EH&S) dept. would ultimately be the ones who would have final approval over the chosen cleaning method.
Chemicals were tried first, however, the cleaning results were inconsistent and more importantly, the wastewater was very difficult and costly to contain. Using chemical cleaners would have involved trapping, storing and then disposing 100% of the water and chemical waste generated. It was decided this method was not feasible due to the risk it presented to the surrounding environment in case something went wrong, and also the enormous costs associated with meeting the project's strict environmental requirements.
Next there was a demonstration done by the Farrow System. This system uses a slurry mixture of a hard abrasive called Olivine, which contains Nickel and Chromium toxic metal compounds. Again, the results were very inconsistent and would have required an excessive amount of containment. On top of that, because the Olivine is hard (similar to traditional sandblasting media), it created surface damage to the Limestone façade, even though a low blast pressure was used. It was decided this method would not work and another non-traditional abrasive blasting solution was tried.
Sponge Jet is a system that embeds a hard abrasive (usually aluminum oxide) into tiny sponge pieces. The sponge abrasive is delivered using a high pressure vessel. This method had the same outcome as the Farrow System: surface damage, inconsistencies, and environmental risk.
The project team was forced to go back to the drawing board, and started to seriously question whether or not it would be possible to find a method that would work. At this point, ESCA (Environmentally Sensible Chemical Alternatives) was contacted and given a chance to demonstrate 2 options: ARMEX Baking Soda and another mineral called MaxxStrip.
ARMEX is a very eco-friendly, SOFT, water-soluble abrasive, and is used extensively today for large scale building restoration projects. ARMEX has been around for over 20 years, and was originally used for the Statue of Liberty restoration. In this case, the baking soda was too soft to remove the black residue from the Limestone.
ESCA Blast then tried another soft abrasive called MaxxStrip (aka Kieserite). MaxxStrip is another eco-friendly, water soluble mineral that has a neutral ph of 7.0 and is slightly harder than baking soda. It turns out MaxxStrip was just hard enough to effectively and efficiently perform the cleaning without causing any damage to the Limestone. The MaxxStrip was wet-blasted at 100 psi, resulting in a dust-free, consistent, and quick cleaning method.
The EH & S staff was very accepting and impressed with the MaxxStrip product. They determined it could be rinsed away into the ground and also go into the lake that surrounded one of their main buildings without risking harm to wildlife, landscaping, workers, or other persons nearby.
The MaxxStrip media, delivery system, PAPR PPE technology, and training were all supplied by ESCA Blast. ESCA has a very simple approach to solving problems for our clients. We listen to their concerns and objectives, and come up with solutions based on our real-world experiences. ESCA Blast prides itself on its commitment to improving both our natural and workplace environment, and welcomes inquiries of all kinds. To learn more, contact ESCA at (800) 699-3722 or visit www.escablast.com.