A truck-rental garage in Prunedale morphs into Jim Dandy's at night.

Photo by Stuart Thorton: Just-Dandy: Jim Dandy (with hat and sunglasses) poses in front of Jim Dandy''s.

It''s a Wednesday night in Prunedale and trucks make a deafening roar while passing by a small, brightly colored building located just 15 or so feet away from busy Highway 101. Inside, oblivious to the passing traffic, bands from all over the West are creating their own deafening roar.

Welcome to Jim Dandy''s, a truck rental shop by day and Monterey County''s only full-time, all-ages, alcohol-free venue for punk rock and heavy metal.

"I want the most outstanding and outlandish venue in the country," says Larry Hemphill, a.k.a. Jim Dandy. By the looks of the place, Hemphill is getting dangerously close to his goal.

Hemphill, a former musician and Vietnam veteran with graying, shoulder-length hair, believes that the United States would be a hell of a lot better if everyone joined him in the mosh pit. He started putting on punk and heavy metal shows at his place 13 months ago, and he tries to get the kids to join him in the pit by offering a cash reward to anyone who slamdances with the most style. The result is a contest that looks like a punk rock version of Saturday Night Fever where tattooed and pierced youth twirl like spastic figure skaters and occasionally throw in a cartwheel for effect.

The young punkers not proving their mettle in the pit or recording the action with digital or video cameras sit on a long wooden bar and swing their legs like innocent kindergartners. Behind the bar, the "bartender," a young man wearing a Tupac T-shirt who looks about 12 years old, serves energy drinks, sodas or candy to the mostly underage crowd.

For Hemphill, making sure that all the kids are alcohol-free is one of his main objectives.

"I''m trying to show the kids that they can have fun without getting loaded," he says.

Tonight, the kids are dancing to the sounds of Breakneck, Hemlock, Maida, The Sky Is a Wall and A Fall Forward. Other bands that have performed at Jim Dandy''s include Bury Your Dead, Scars of Tomorrow and Bleeding Through.

Maida, a hardcore band from San Jose, made the 45-minute drive down to Prunedale tonight to perform at Jim Dandy''s for a second time. "We love it here, man," says vocalist Rob Monroe. "It feels comfortable here."

Monroe is not the only one who enjoys Jim Dandy''s eclectic atmosphere. Rodney King, 20, figures that he has been to 30 or 40 shows at Jim Dandy''s, including the inaugural night when The Sky Is a Wall performed.

On an average Wednesday night, Jim Dandy''s draws more than 100 young punkers, mostly through word of mouth. It is hard to find the venue''s schedule, because Jim Dandy''s is not listed in the phone book, and it does not have a Web site.

Photo: Dreaded: Chad Smith of Hemlock

While some of the kids stand outside socializing in a small parking lot covered with woodchips, Hemlock, a band from Las Vegas, puts on a frightening performance. Bassist/singer Chad Smith swings his dreads around like a possessed rag doll while singing songs like "My Eyes Itch."

When Maida performs, Monroe dedicates a song to The Sky Is a Wall and adds, "There is no scene, just bands like us and them." For Maida''s last song, Monroe sings the lyrics while lying face down on the floor. By the time he is finished, Maida''s drummer has already quietly taken down most of his drum kit.

Hemphill announces The Sky Is a Wall as his house band, and then, during the band''s set, he leads a group of young punks in a slow-moving whirlpool around the mosh pit. After the set, singer Jerry Wayne ignores the crowd''s request for him to continue performing, because he says that the last band, Los Angeles'' A Fall Forward, deserves the dwindling crowd''s attention. Then, a few members of the crowd react by tackling Wayne and then joking with him like he is their older brother.

It may seem like a strange place to go to have fun. But to a lot of young local punk rock and metal fans, it feels like home.

Jim Dandy''s is located at 1031 El Camino Real, just south of the 156 overpass on Highway 101. Call 663-4047 for more information.