The roof of the 15th-century monastery had to be fully replaced. image: Broughton Coburn for the American Himalayan Foundation

You’ve heard of "high-technology" and even "low-technology," but how about "mud-technology"?

"Mud-technology" is just one tool being used in restoring valuable and ancient pieces of art.

Something old, something new, and even some blue

Deep in rural Nepal, in a place rarely seen by outsiders, a 15th century Buddhist monastery was restored using both ancient technology and modern technology.

"We're repairing a building which is built of impermanent materials,” architect John Sanday of the American Himalayan Foundation told PBS's NOVA. “And we're faced with the problem of repairing and conserving that."

Before he could get started, Sanday had to win over the residents of Mustang, home to the monastery. They were reluctant to turn over one of their sacred treasures to Westerners. Recalling his first warning, Sanday told NOVA, "We were told be careful of the locals. You'll find them particularly difficult and bad-tempered." It was then he realized that "one of the most important things is to gain people's confidence."

As shown on "NOVA", he gained their trust, and the structure was repaired with timber carried over the border from China, plus mud and clay found in the area. Clay is Mustang's unique technology. Local residents are masters in mud laying and their expertise was invaluable to Sanday.

But for the carpentry work, Sanday knew he needed some outside help. "I realized that I needed to bring up a group of carpenters to teach the local carpenters the whole process of how to repair and conserve timber structures," he told NOVA.

Paintings of the gods

20-foot painting of Thubchen, the Buddha of the present. image: Broughton Coburn for the American Himalayan Foundation

Art conservator Rodolfo Lujan was brought in to save the monastery's giant wall paintings of Buddhist gods. Using what he called the "mud technology" of the region and a special adhesive, the conservationists re-attached the paintings that had separated from the walls after decades of water damage.

To clean the paintings the team used the same method that was used to restore the Sistine Chapel.

"The Sistine Chapel was covered with soot, dust, smoke—coatings of various nature. And what do we have here? Exactly the same thing," Lujan told NOVA.

Two everyday chemicals, ethyl alcohol (ethanol) and powdered ammonium bicarbonate (an early form of baking powder), were mixed together to make a solution that dissolves grease and surface dirt without removing the paint. The mix was tested many times to find just the right blend. Any mistake could be permanent.

"There are some areas and some pigments that need special care," Lujan told NOVA. “And so there we go very carefully. Accidents can always happen... You can take away a little bit of paint.”

After years of work the final touches were put on. The consensus: a job well done.

Nova airs on PBS. For more information, visit pbs.org/nova.