Apr 7, 2015 11:19 AM

David Slater’s Sag Harbor studio overflows with stacks of huge oil paintings, mosaics, collages and mixed media assemblages—evidence enough of his lifelong devotion to his art.The subjects range from nautical scenes and his own backyard to self-portraits and erotic nudes, though a similarity of bold colors, intense energy and endless action pervades them all.

In celebration of his 60th anniversary as an artist and a career spanning hundreds of exhibits around the world, Mr. Slater will exhibit a solo show opening Saturday at Peter Marcelle Project in Southampton.

Although Mr. Slater is finally at the top of his game, it didn’t come without some major obstacles, among them his father—a World War I veteran and fellow artist whose creativity blossomed during the Great Depression.

“He said if he ever saw me picking up a paintbrush, he’d slap my hand,” Mr. Slater recalled, sitting in his Sag Harbor studio, surrounded by his vibrant, abstract paintings. “He wanted me to be an athlete. He was obsessed with golf and tennis, which I tried but had little interest.”

A sensitive, intuitive Scorpio, Mr. Slater said he knew he wanted to communicate, in some way, his own unique perception of the world. With his Einstein-like wild, long gray hair and black-rimmed glasses, he is still the quintessential hippie. He said he has always been fascinated by the occult world, by ghosts, spirits and his dreams, and has wanted to share them.

Born in Hempstead, it wasn’t until a young Mr. Slater was 15 and moved to Massapequa that he took a basic art course in high school. “I knew from that time on that I wanted to be an artist,” he said. “I flunked all my other courses, but I did great in art.”

So great, in fact, that, 60 years later, Mr. Slater is surrounded by a lifelong body of work that fills his small studio and most of his duplex apartment, as well as the houses of his friends and family.

He formally began his art career at Buffalo State, where he earned a bachelor’s degree in art education. He taught art in the Glen Cove School District before marrying at age 23 and traveling Europe with his now ex-wife, Virginia.

He moved to Sag Harbor in 1982, after his adventures took him to Wounded Knee, South Dakota, during the anti-Vietnam War movement, to help Native Americans in their 72-day armed siege, protesting their corrupt tribal president.

These autobiographical narratives are infused in each of his paintings. “I’m constantly telling stories about myself on a visual level,” he said. “I feel a need to share my life experiences.

“People ask me, ‘Why do you have to fill in every little space in your paintings?’” he continued. “I tell them I have ‘horror vacui,’ which is ‘fear of vacant spaces.’”

This carries over into Mr. Slater’s art studio and adjoining living room, which are like museums unto themselves. One whole wall of shelves houses numerous sentimental collections from his travels, at different stages of his life.

There are hand-painted wine and liquor bottles, including one he found in Germany while hitchhiking through Europe with his wife after college. There are little green folk-art trees that he found at a yard sale with his former girlfriend, artist Elisca Jeansonne, and bright-colored, antique Christmas ornaments he’s collected and hung in rows. There are African woodcarvings and Indian relics, and even a golf trophy his father won the year he was born. He collects broomsticks, table legs and canes. There is even a collection of miniature wooden chairs.

In between Mr. Slater’s souvenirs are his 6-foot paintings, propped against couches, stacked against walls and hung wherever space is available. Several of them are tapped from his dreams, including the largest one, “Ghost Ship,” which will be on view during his upcoming show.

“In my dream, I looked up and saw this derelict sailing ship, all covered with salt and the sails in tatters, and it slowly came up to Long Wharf in Sag Harbor,” he said. “The only living thing was a cat, and I tried to save the cat, which ran into a crowd on the dock. And then I woke up.”

Another painting in his upcoming show, “The Ghost in My Back Yard,” is an intricate scene of his back patio, with tables and chairs, flowers, trees, a hummingbird and an eagle, all set against a blue latticework fence. But there is also a “ghost boy,” as Mr. Slater calls him.

“My backyard is a magical place,” he said. “It’s a place where I leave the physical world and encounter the spiritual world, and there is a ghost in and around my apartment, which was built in the 18th century to house the workers from the Bulova Watch Factory.”

This vivid imagination and unique style is what inspired Southampton art dealer Peter Marcelle to represent Mr. Slater over the past seven years, and the new show is a retrospective, of sorts, incorporating both his early and more recent paintings.

“David is incredibly expressive. I like his creative process—it’s an extension of his whole being,” Mr. Marcelle said. “It’s like a journey of his mind and his whole life. Whether you like him or not, he’s the true definition of a painter. History is going to be good to David Slater.”

“Something Old, Something New,” a solo show by David Slater, will open with a reception on Saturday, April 11, from 6 to 8 p.m. at Peter Marcelle Project in Southampton and will remain on view through Sunday, April 26. A percentage of proceeds will benefit the Sag Harbor Whaling & Historical Museum. For more information, call (631) 613-6170, or visit petermarcelleproject.com.