"When you make nails like this, you quickly learn why, when people moved, they burned their house down to get the nails," he notes. "Nails are a lot of work."
Which is probably why they're made by machines now.
Brooks molded the nail head in a curious little tool with a hole at the end. Asked what it's called, he said, with a shrug, "a nail header."
Brooks said he's not a professional blacksmith, although he's been giving demonstrations as a National Park Service volunteer for several years - first at Harpers Ferry National Historical Park and now at Catoctin. But he's "been messing around with it since I was a little kid." He just likes melting metal and making something else out of it.
"We usually use steel now," he said. "Real wrought iron is hard to get."
Brooks is one of a handful of volunteers who demonstrate smithing at the park. He was working on another park project when he discovered the park's blacksmith shop.
One of the first buildings constructed at the park in the 1930s, it was "a working blacksmith shop," used by Works Progress Administration employees to make hinges and latches for park buildings, he said. The shop is on National Register of Historic Places.
Exhibits explaining the art of smithing surround visitors to the shop. A blacksmith, according to one, "is a jack of all trades and is an important member of his community. He makes tools, nails, hinges, rims for wagon wheels, link chains, knitting needles, and ox yokes. He repairs farm machinery, replaces wooden handles on tools, shoes horses and occasionally pulls teeth."
Hagerstown resident Paul Helm watched intently as Brooks worked. An aficionado of 18th-century weapons, he asked whether Brooks has ever made a gun barrel.
"I've made muzzle-loading rifles," Brooks replied, "but I've never made a barrel."
"It's quite an art, really," Helm said.
Eight-year-old Julia O'Connor, who lives near the park and was visiting with her mother, Elizabeth, wanted to know how they put holes in horseshoes.
"They punch 'em," Brooks said - and showed her the notch in the anvil where the punch goes through.
Julia had never seen a blacksmithing demonstration before, but said she would like to learn how to do practice the trade.
"I think it's cool," she concluded.
Especially in January.