Experts Try to Age-Proof Old Mission : Preservation: The trick is to render the San Juan Capistrano landmark impervious to further deterioration without diluting its historic flavor.

While electricians dug delicately around the artifact-rich Mission San Juan Capistrano grounds last week, preservation architect John C. Loomis studied the crumbling brick and sandstone archway that frames the mission’s peaceful courtyard.

“These guys are basically flapping in the breeze,” Loomis said, pointing to the free-standing arches that were built in the late 1700s by local Indians and Spanish settlers. “There’s nothing to hold them up.”

In order to strengthen the wobbly brick columns, workers will soon install a network of steel straps that will be virtually invisible to the thousands of tourists and schoolchildren who come to the mission for a taste of early California history.

For more than a year, a team of historians, architects, structural engineers, archeologists and other scientists has studied the touchy question of how to save the aging mission without destroying the historical monument they are trying to preserve.

“We’re in danger of losing our California heritage if we don’t take corrective steps to preserve the mission,” said Loomis, who is director of the mission’s ongoing Third Century Stabilization Project. The project is sponsored by the Diocese of Orange County.

Much of what the team of researchers has studied will lead to new techniques for preserving California’s 22 Spanish missions, the state’s earliest architectural treasures.

“I’ve done a lot of remodeling in my day,” said Robert B. Marusich, an electrical engineer who is working on the project. “But nothing I’ve ever done has prepared me for this.”

Often going without any blueprint to guide them, researchers have had to walk through the mission cataloguing almost every detail of the 214-year-old structure, the oldest and one of the most picturesque historical monuments in the county.

What they learn will be bound in a “Preservation and General Master Plan” that, when implemented, will guarantee that the mission will remain intact through the middle of the 21st Century.

“There has been nothing to go by,” Marusich said. “It’s like playing detective.”

The ongoing study of how to preserve the mission has been so successful, Loomis said, that he and other mission specialists from Orange County were invited to be featured speakers at a first-of-its-kind conference on the future of the Spanish missions. The conference began Sunday in El Paso, Tex.

Mission representatives from five Southwestern states are meeting to discuss formation of an umbrella organization that will study new preservation technologies as well as fund-raising, tourism and marketing strategies.

The dozens of missions in California, Texas, Arizona, Nevada and New Mexico are considered the cornerstones of Southwestern history. And although they were built about the time of the Revolutionary War, they are in far more danger of falling prey to destruction than are even older historical buildings in the East because of the fragile materials used in their construction, Loomis said in an interview last week.

When the Mission San Juan Capistrano group returns from the conference, it will begin implementing the preservation techniques that the team has worked out, mission officials said.

Mission museum director Nicholas Magalousis said the preservation project is not geared to turn the mission into a replica of what it used to look like when it was first built, but rather to prevent the mission from further deterioration.

“We’re not trying to restore the mission,” Magalousis said. “It’s an attempt to freeze the existing structures as they are.”

Some of the preservation techniques are simple, tried-and-true methods, such as strapping shaky columns and replacing rotting wood. But some of the other preservation methods, such as those for keeping 200-year-old adobe from reverting to dirt, are yet to be formulated.

“We have more questions than answers, to be quite frank,” Loomis said. “But we are learning more and more.”

To be sure, Mission San Juan Capistrano, known as the “Jewel of the California Missions” because of the yearly return of the swallows, is more than just a little rough around the edges.

Many parts of the ancient adobe walls are crumbling or melting from rain and moisture from the nearby ocean.

What is left of the Great Stone Church, devastated in an 1812 earthquake, is suffering further damage from pollution and weathering. Many of the sandstone blocks that were carted to the site from quarries in Mission Viejo and Ortega Highway canyons are splitting prematurely.

Magalousis said the project does not come a day too soon, especially in view of the ever-present threat of a major earthquake.

His fear that an earthquake would finish the mission he has studied for more than a decade is so great that when the Upland quake shook a wide area of Southern California on Feb. 28, he spent hours checking over the mission walls.

“I was driving home (when the earthquake hit),” Magalousis said. “I made an immediate U-turn back to the mission.”

Structural engineer Robert Lawson said it is his job to make the mission’s buildings earthquake-proof by developing techniques that will not detract from the historic quality of the mission.

“When we get done, if we do it right,” Lawson said, “nobody will notice it.”

The most problematic issue facing scientists at Mission San Juan Capistrano and other missions is how to preserve the adobe bricks that were formed from dried earth.

Each time it rains, Loomis said, a portion of adobe is washed away. In fact, some California missions are in such a bad state of deterioration that some walls are nothing more than piles of dried mud.

Certain missions, such as the San Gabriel Mission in Los Angeles County, are now closed to the public because of deterioration and earthquake damage.

Loomis said San Juan Capistrano mission officials are looking to the Getty Conservation Institute for answers on how to preserve the adobe.

The institute has been working on the problem for several years in a laboratory in Las Cruces, N.M., said Loomis. Among possible solutions is coating the adobe or injecting it with hardening chemicals.

Mission officials have also submitted a request for a grant from the institute to help raise money to pay for the stabilization project, which is expected to cost more than $25 million, and the Getty Conservation Institute is considering establishing a field-test site at the mission.

But mission representatives are not waiting for the next grant to begin implementing what they have already learned. A large, hidden electrical transformer was recently installed in a corner of the mission, next to the low-slung soldiers’ barracks. A second transformer will be installed next year. The new wiring will replace an electrical system that was installed in the 1920s.

Beginning next month, scaffolding will be erected around the Great Stone Church and will remain wrapped around the ruin for the next five years, Loomis said.

Workers will then begin the slow, tedious job of re-facing the crumbling sandstone blocks and drilling deep holes into the three-foot-thick stone walls to install earthquake retrofitting bars.

Some of the stone is so badly deteriorated that workers will have to try two or three different preservation techniques to save it. Older preservation methods which, in the past, made the erosion worse will also have to be discarded or corrected, said Loomis.

“It’s going to be a stone-by-stone process,” he said. “It’s going to be very expensive and very time-consuming. But we want to do this right.”

Times correspondent Len Hall contributed to this report.