Bombs restored with zinc, muscle
KADENA AIR BASE, Okinawa — Renovating bombs in the Air Force is a business both little known and narrowly practiced — not because of the danger but because the only bomb renovation plant in the entire Air Force is on Kadena Air Base.
The 18th Munitions Squadron’s bomb renovation site was built in the late 1960s, said Capt. Chad Heyen, the squadron’s maintenance operations officer. Even bombs, he said, need preventive maintenance.
“We have a lot of ‘dumb’ bombs that get corroded over time,” Heyen said. “We used to paint them every five years. Now, we coat them with zinc and that lasts at least 20 years.”
Heyen said testing the zinc coating showed the only time a bomb corroded before the 20-year mark was if the coating was too thin, or if a spot was missed.
Master Sgt. Andrew Morris, maintenance flight superintendent, said using the zinc coating has saved a lot of money. “It used to cost $300 to renovate each bomb,” he said. “Now it costs only $25.”
Morris said they can complete a 2,000-pound MK-84 bomb in just 10 minutes; the smaller, 500-pound MK-82 takes just five.
When bombs arrive at the plant, they’re first put on racks where the fuse wells are cleaned and sealed, said Morris. They then make their way to a conveyor, where they are hung vertically.
Next, the bombs visit a chamber where all the corrosion and old paint is stripped off. Basically, Morris said, they’re sandblasted clean.
The bombs then enter another chamber where the zinc coating is sprayed on. Morris said two solid bars, one of zinc and one of aluminum, are melted by a welding process and the liquid is sprayed onto a bomb’s surface. The bomb spins as the sprayer makes its way from top to bottom, to ensure an even coat.
Morris said after the spraying, workers test to make sure the zinc is thick enough. If it is, the bomb is pulled from the conveyor and returned to storage.
Morris said approximately half of the 18th MUNS MK-84 bombs, and an eighth of the MK-82s, have had the zinc treatment. Once Kadena’s stockpile has been treated, he said, it more than likely will be swapped with another base — and Kadena will have a new crop of untreated bombs to work on.
— Fred Zimmerman