If customers start talking about blood and guts while examining his vast collection of knives, swords and hatchets, Richard Nelson quickly changes the subject. 

“I don’t get into talking with them about the bad end of it,” he said. “I tell them, ‘I don’t want to be a witness to whatever it is that you’re about to do. I run a clean business.’”

For the last three summers, from May through September, Mr. Nelson has set up his itinerant knife stand on B Street, just around the corner from Highway 1 in Point Reyes Station. His poster-sized, hand-painted signs mark the spot: “Damascus knives.” “Knife sharping.” He’s usually there from Thursday through Sunday.

His customers are travelers looking for souvenirs, sportsmen searching for hunting knives and local foodies who ask him to hone their chef’s knives, which Mr. Nelson does with skill and dispatch.

Others are interested in more exotic wares: swords and medieval-style blades popular with fantasy buffs. If things get weird, which they do every now and then, he gently tells them to cool it. “I’m good with people,” Mr. Nelson said. “I’ll take bad conversations and make them good.”

A soft-spoken man, Mr. Nelson attended West Marin School when he was a kid and his dad was working as a ranch hand on the Nunes ranch. The family later moved to Petaluma, and Mr. Nelson now owns property down in Weldon, at the southeast tip of Lake Isabella in Kern County. 

He wears steel-rimmed glasses, a blue button-down shirt and a black felt cowboy hat. At 70, he’s hard of hearing and must stand close when his customers speak.

He calls his business Knives Are Us, and he spends much of his time on the road, traveling to flea markets and gun shows in California, Nevada and Arizona. He’s been at it for 40 years now. He packs his wares in a Wells Cargo trailer attached to the back of an old Chevy camper van and hits the highway.

When the temperatures are broiling down south, he heads up to the cooler climes of his West Marin hometown, where he spreads his collection atop folding tables, most of it displayed in glass cases. There’s a wide array of pocketknives, bowie knives, chef’s knives and the unusual medieval-style blades that might look at home in a video game. He had been selling crossbows but stashed them away after they raised a few eyebrows.

“You’ve got the liberal people, and they will call and complain,” he said.

He does his best to stay in the good graces of the authorities. He counts local firefighters and sheriff’s deputies among his favorite customers.

Mr. Nelson charges a dollar an inch for sharpening. He gets his knives from a supplier in Baltimore. Because he’s been selling for so long, he buys them at a discount, which he can pass on to his customers. He says he can sell a chef’s knife that might typically cost $160 for half that price. 

His biggest sellers are chef’s knives and hunting knives, though he does sell a sword from time to time. Those go for $250. 

Damascus knives, carbon steel slicers distinguished by water-like patterns on the blade, are constructed with layers of steel forged at very high temperatures and pounded together with a hammer. There are some counterfeits on the market, but Mr. Nelson said his are the genuine article. 

When he first started selling them 40 years ago, Damascus knives were produced in the United States. They are now produced on assembly lines in Pakistan, where labor is cheaper. Nevertheless, Mr. Nelson said the quality is still good.

Even after four decades on the job, he has never had a serious injury. “I’ve been lucky, I guess,” he said. “I’ve never really got cut real bad. I don’t have any scars on my hands. I’m really careful. You can’t move fast with these blades. You’d better take your time with them.”

Mo Blumenthal, a home chef whose culinary predilections run from Italian to Indian and beyond, stopped by on a recent afternoon to pick up three knives she left with Mr. Nelson.

“He does a good job, and the price is good,” she said.

Mr. Nelson sometimes bumps into old classmates who barely recognize one another six decades later. Recently, his old elementary school buddy Bruce Stevens stopped by the stand, wearing a ponytail and a cowboy hat. 

“They called me the Rooster,” he said with a toothless grin.

“My nickname was the Gopher,” Mr. Nelson said. “I don’t remember why.” But everyone had a nickname in those days.

They reminisced about teenage antics, including the time a mutual friend took them on a hair-raising car chase along the winding roads of West Marin with sheriff’s deputies in hot pursuit. 

During his first summer back in Point Reyes, Mr. Nelson set up his tables just around the corner on Highway 1. It was Mr. Stevens who advised him to move to the quieter location on B Street, where customers are less likely to block traffic and raise the ire of authorities.

Mr. Stevens gestured at the sanding machine that Mr. Nelson uses to sharpen knives, the mainstay of his Point Reyes business. “You’ve living the dream,” Mr. Stevens said. “Everybody needs their knives sharpened.”

“It’s been keeping me alive,” Mr. Nelson agreed.

He powers the machine with a generator, and it doesn’t take him more than a minute or two to get the knives finely honed. 

“It’s an art,” he said as he gently pressed the blade of a chef’s knife to the spinning belt of sandpaper, angling it to about 20 degrees. “I could do this with my eyes closed.”