Cyndi Loza

The Museum of Science and Industry is getting a long-awaited facial. The building’s exterior will be cleaned of seven decades of grime and pollution in preparation for its 75th birthday next year.

The north side of the building is in the process of being restored to its once-soft sand color, with the east and west sides scheduled to follow. The project should be completed by October.

“We take a lot of pride into our building — the exterior, the interior and the people that are in it,” museum spokeswoman Lisa Miner said. “So we’re excited to have it cleaned in anticipation to the 75th anniversary launch.”

So, how do you wash off decades worth of buildup?

The process is a delicate one, according to museum capital program manager M. Richard Klarich. They found that cleaning the Indiana limestone that cloaks the building is best done through a long, soft water soak.

Miner said most of the lighter stains on the building’s surface are removed by first pre-wetting the affected area and then brushing on a mild biocide followed by a low-pressure water rinse. Darker stains are exposed to low-pressure water misting for two hours and scrubbed, when necessary, with a soft brush with very low water pressure.

While some may welcome the newly spruced-up museum, others will miss its grimier facade. “I kind of like that dark, dirty look to it,” said Fred Ruiz, 46, who is visiting with his family from Tucson, Ariz. “It kind of makes it look imposing.”