GRAVES LEDGE, BOSTON HARBOR — Dave Waller and Bobby Sager are used to taking on daunting projects. A decade ago, they bid against each other at the government auction for Graves Light, a historic lighthouse that rises from a rocky ledge in Boston Harbor, more than 4 miles out at sea.
Waller won with a $933,888 bid, but the kindred spirits later teamed up to restore the weathered beacon and recently installed a classic Fresnel lens that Waller built piece by piece in his Malden living room over many years.
When Graves Light was first lit in 1905, it was illuminated by a first-order Fresnel lens — an elegant structure of glass prisms that reflects and refracts light into a beam that can be seen at a distance on dark and foggy nights.
When the Coast Guard automated the lighthouse in 1975, it removed the Fresnel lens. But Waller, 60, who co-owns a neon sign shop in Somerville and has long been fascinated by Graves Light, always hoped to bring it back.
Earlier this month, in an intricate operation that required two helicopters, many boat rides, and countless hours of work, a handcrafted version of the original lens was brought to the lighthouse at the outer reaches of the harbor.
It took about nine years to track down and craft all the pieces necessary to assemble the massive lens in Waller’s spacious Malden home, which was once a firehouse.
It all started with “a jumble of parts,” Waller said. “We built the whole lens in our living room.”
Named after French physicist Augustin-Jean Fresnel, Fresnel lenses came in different sizes, known as “orders,” and were used in lighthouses for many years.
But today, they are “crazy rare,” Waller said.
When the original Fresnel lens was removed from Graves Light, the Coast Guard sent it to Washington, D.C., to be displayed as part of a bicentennial exhibit. It was then placed in storage at the Smithsonian Institution, where it has remained, Waller said.
Waller asked around, but people told him it would be impossible to convince the Smithsonian to hand over such a rare artifact. So he set out to make one himself.
It wasn’t easy. While there are first-order lenses on display in some museums, Waller couldn’t locate any that were privately owned. So he began to collect the parts, piece by piece.
“They’re really hard to find,” he said.
He eventually acquired two pieces of a first-order lens from a dealer in Michigan who sells lighthouse-related artifacts. Then he got some more pieces from Tim Nguyen, a lighthouse lens engineer in Australia who Waller came across online.
Nguyen ended up playing a key role in the project, because he was able to fabricate the missing lens panels by using original prisms and old blueprints as a template.
With the help of his sons, Emmett and Wyatt, Waller assembled the lens in his living room.
This month, Waller and his team began the arduous process of transporting and installing the lens. They used stretchers to carry pieces of the lens out of his home, loaded them onto a flatbed truck, drove them to a warehouse in East Boston, and put them on a boat bound for Graves Light.
The two largest pieces had to be flown in by helicopter. The trimming stage (the platform where the lightkeeper would stand to light the wick every night) and the spider gear (which turns the lens at two revolutions per minute) each weigh about 1,100 pounds, Waller said, so the Coast Guard flew them out on separate trips.
Watching the helicopter tow the two largest pieces through the air was majestic, if stressful, Waller said.
“My heart was in my throat,” Waller said. All he could think was “please, please, please” don’t let anything go wrong.
The helicopter had to maneuver carefully around the tower while carrying each piece, and in one harrowing moment, a piece came close to hitting the top of the lighthouse.
“It came within a foot of hitting the glass,” Waller said. “It would have been an absolute disaster.”
The Coast Guard helicopter placed each piece on the bridge that connects the lighthouse to a converted oil house. A smaller private helicopter then brought the pieces to the lantern room at the top of the lighthouse.
Restoring the beacon has been a labor of love for Waller, who has known about Graves Light since he was a kid. A few years after he and his wife, Lynn, bought the lighthouse at auction in 2013, they partnered with Sager, a philanthropist, artist, and photographer who wanted to help restore the lighthouse and was willing to provide additional financial resources to do so.
Earlier this month, Sager went out to the lighthouse to watch the Fresnel lens arrive.
“There’s powerful symbolism there,” he said. “It’s literally a beacon, guiding people at sea and guiding people on their journey.”
While Graves Light is privately owned, the Coast Guard continues to operate and maintain its beacon and fog signal as navigational aids. Many lighthouses remain active and continue to serve as useful landmarks to guide seafarers home, although modern navigational methods such as GPS, nautical charts, and radar beacons play the dominant role.
For Sager, the lighthouse is a source of inspiration.
“My motivation in doing this is really simple,” Sager said. “It’s this idea that it’s going to be a light projecting out into the world, and it should be an authentic light.”
Waller likens the lens to a sculpture that’s not only beautiful to look at but also practical and functional.
“It’s an absolute work of art that does its job,” Waller said.
And now the lens is where it belongs.
“It’s one thing to see this in a museum,” Waller said. “But it’s something else to see it working in a lighthouse.”
Emily Sweeney can be reached at emily.sweeney@globe.com. Follow her @emilysweeney and on Instagram @emilysweeney22.