The only surviving Civil War city-class gunboat was hosed down Tuesday with a simple solution that should help the aging boat last for generations.

Dr. Terry Amburgey, owner of Starkville-based Wood Protection Specialists, and his crew used water hoses attached to a large plastic drum to apply a boric solution to the wood of the USS Cairo in Vicksburg National Military Park.

“We feel confident that with the canopy and treatment, this will be here for another hundred years,” Amburgey said.

The solution, which was donated by U.S. Borax, is designed to prevent fungi, insects and humidity from damaging the wood of the 153-year-old boat, said Amburgey, who is a retired forestry and wood preservation professor at Mississippi State University.

“This is the third time we’ve treated this wood in 10 or 15 years. We’re not re-treating it because the former treatments got dissipated. With this treatment when you load up the outside, in time it wants to go all the way through the wood and establish a uniform treatment level,” Amburgey said.

The material is deadly to insects, but nontoxic to humans and other mammals, he said.

“Everyone at some time or another has used Borax in their laundry,” he said. “Contact lens solution also contains Borax.”

USS Cairo Museum curator Elizabeth Joyner said the treatment process was essential for the survival of the Cairo.

“We’re just excited to finally get this treatment for the gunboat,” Joyner said. “It’s so critical for the continued preservation,”

The boat was commissioned Jan. 25, 1862, and it was sunk by an electronically detonated mine Dec. 12, 1862 in the Yazoo River. Ed Bearss, Don Jacks and Warren Grabau discovered the wreckage in 1956, though the site had been speculated to be the resting place of the Cairo for years. The remains were split into sections and raised in 1964.

But after it was raised, the wood of the boat that had been underwater for more than 100 years began to deteriorate.

“It was OK as long as it was under water, but when the raised it out of the Yazoo River they didn’t have a plan in place,” Amburgey. “A lot of deterioration you see happened during that period of time. The detrition was there when we started. There was nothing we could do, but we can stop it where it is.”

Amburgey first saw the Cairo shortly after it was raised and hauled to Pascagoula, but he became involved in its restoration under retired park superintendent Bill Nichols.

“At that time they didn’t have as nice of a canopy as they do now. The wood was getting very wet. They were concerned they were not going to have a boat, and we had to do something about it,” Amburgey said.

The USS Cairo receives an average of 300,000 visitors per year who get first-hand experience of stepping aboard the only surviving ironclad gunboat, Joyner said.

“We get a lot of repeat visitors to the site,” she said. “Occasionally we still get people who saw it being raised and share their stories with us.”

The boat was closed to tourists Tuesday but was expected to reopen Wednesday morning. Admission to Vicksburg National Military Park is $8 per noncommercial vehicle. For more information on the USS Cairo, call 601-636-2199.