One of Mao's men fills the nose cone with kindling. The fire will be used to set off the detonator still inside.
S itting astride a 250-kilogram live bomb dug up in Kampong Thom province, Yib Mao carefully dripped water from a plastic bottle into the cut he was making with a hacksaw.
Mao feared a spark could ignite the several kilograms of TNT he was trying to extract, meaning certain death for him and his fellow bomb salvaging crew.
Smoking cigarettes around the bomb, however, was considered fine by Mao's team.
The high quality components used in bombs, mortars and grenades encourage many Cambodians to forgo the risks in pursuit of income, mostly from the region's thriving scrap metal industry.
"Once we used to run away from the bombs, and now we run to them," said Mao, who recalls the bomb falling near his home village of Prek Kdei in 1972.
The rush to turn old war tools into cash is a key topic in a new report entitled Tampering, written by Richard Moyes, that looks at the deliberate handling and use of live ordnance.
It's also the focus of a documentary currently being shot by filmmaker Skye Fitzgerald and sound engineer Chris Parkhurst.
On a visit to Cambodia in 2001, Fitzgerald met Aki Ra, the proprietor of the Land Mine Museum in Siem Reap, and was taken by the idea of producing a documentary on land mines.
After securing funding from a Fulbright Commission research grant and broadening the film to include recycling of unexploded ordnance - commonly referred to as UXO - as well as the demining of villages, Fitzgerald returned in 2004 to start the project.
In October of 2004, a scrap metal middleman invited Fitzgerald and Parkhurst to Prek Kdei - a rough two-hour moto-taxi ride from Kampong Thom town - to observe a small crew of UXO salvagers taking apart a monster bomb.
A villager had found a detached tail fin using a metal detector and guessed correctly that the rest of the bomb was buried below in the loose soil.
While rust had long since obliterated any identifying markings on the shell, Mao recalls the bomb falling from a US Air Force B-52 in the rainy season of 1972, when the soil was soft.
It failed to explode on impact and remained buried nose-first with its detonator intact about five meters below the surface.
While Cambodia is well known for its landmine problem, it was also pounded with bombs between 1969 and 1973. The US dropped 500,000 tons of ordnance on Cambodia - three times the amount dropped on Japan in the closing stages of World War II, according to historian David Chandler.
More than 30 years later, Fitzgerald filmed the salvagers of Kampong Thom as they dug a pit around the bomb and built a frame from tree branches to help them winch the fat, meter-long missile up to the surface.
"Their chain wasn't long enough to go around the bomb as well, so they cut vines and extended the chain," Fitzgerald said. "Two experienced men went down into the hole and secured vines around the bomb. We filmed that with a lipstick camera on one guy's head."
For three days, Fitzgerald and Parkhurst filmed from an elevated vantage point as far away as the thick jungle would allow them, observing the crew delicately hacksaw into the still live bomb.
"They had a certain knowledge base, which gave us some confidence, but we had to have a clear understanding that if we felt things weren't safe for us, we could call a halt," Fitzgerald said.
The TNT, which had hardened into concrete-like chunks over time, was eventually removed and taken away in three full rice sacks.
Previously, a strong demand for quarrying and mining explosives drove a healthy market in TNT but since the government has cracked down on the transporting of TNT from UXO, the risk of being fined $500 outweighs the profits.
The group took the TNT at night and buried it at a roadside location for retrieval when transportation restrictions might be relaxed, Mao said.
Three pieces of metal casing remained, including the nose cone, which held the detonator.
To disarm the detonator, the team pointed the nose cone into the ground and lit a fire inside it.
"We were still close by, and we called a halt and retreated to a safer distance. We didn't know what might happen, but it would probably be similar to a landmine blast, although directed upward by the shape of the cone," Fitzgerald said.
With uneasy anticipation, they waited as the fire burned.
"Nothing happened," Fitz-gerald explained. "So two guys went up and stoked the fire, turned their backs and began walking away. They made it about 20 feet before the detonator exploded."
The blast was indeed directed upwards and no one was injured.
A metal buyer from Kampong Thom town was called in and offered the villagers 580 riel for each of the 150 kilograms of scrap metal from the bomb casing.
After eight days of life-threatening work, the group spilt their $22 earnings more or less evenly between the five-man team.
"The Thais who buy this stuff in Poipet are making the most money," Fitzgerald said.
Except for a very small amount that travels into Vietnam, Fitz-gerald found that most scrap metal collected in Cambodia, including that from UXO, is funneled through Poipet across the border to Thai smelting factories.
There they are typically turned into construction beams and reinforcing rods.
Trucks do a circuit about every three months and deliver their cargo to eight sorting yards in Poipet, Fitzgerald says.
The yards sort the metal into three piles: safe UXO, unexploded UXO and other metal. Fitzgerald estimates that five to 10 percent of the recycled metal is UXO salvage.
Following a UXO blast in 2001, the Thai factories now levy fines of at least $250 if sorting yards let any unsafe materials cross the border.
Thai-registered trucks cross the border to collect the material, paying the yards between $100 and $250 per load, depending on the quality, and drive it to the smelting factories, sometimes returning that same afternoon for more.
The owner of one Poipet scrap yard walked Fitzgerald past huge piles of rusted metal to an entire ordnance section where hundreds of unexploded rockets, mortar projectiles and bombs lay in varying states of decay.
The chief ordinance cutter, Chay, uses an oxy-acetylene gas torch to cut the bombs and mortars lengthwise, stopping occasionally to pour water when the TNT inside begins to burn.
"Once, he picked up a burning mortar bomb and ran 30 feet to toss it into a small pond to prevent it exploding," Fitzgerald recalled. "Another worker balanced mortars between his feet and methodically pounded them apart using a large hammer."
Every so often, things go awry.
On December 26, an old bomb exploded at a scrap metal shop in Banteay Meanchey's O'Chrou district, not far from Poipet.
Two kilograms of shrapnel ripped through Tong Hout, 39, who was standing 100 meters away at the time, breaking his left hand and injuring his chest, according to media reports.
Police said the bomb was being dismantled but did not mention any casualties among those working on it.
Statistically, Cambodians are now more likely to be killed or injured by old bombs than by landmines.
Recent figures show that in November 2004, UXO were responsible for 40 casualties (including 10 deaths) while 27 people were injured or killed by landmines. This reflects the trend over the past four years.
More than half of those people involved in UXO accidents last November were civilians deliberately handling the ordnance.
In Sra'em village near the northern Thai border in Preah Vihear province, Moyes found an empty mortar bomb being used as a striker for a bell made from a truck wheel.
The village chief would use the "bomb bell" to call people to community meetings - including forums advising locals not to handle ordnance.
"People are surrounded by the remnants of war on a daily basis; they wake up next to them, step over them on their way to school and use them as house building materials," said Skye Fitzgerald.
But it's tampering that causes the bulk of UXO casualties.
"I don't think anyone who is trying to feed a family should have to risk life and dismemberment by taking a hacksaw to a bomb," Fitzgerald says. "But there's an element of hope that they are putting food on the table by salvaging these containers of TNT that were meant to kill and maim them."
(Additional reporting by Liam Cochrane)