How to Build a Name : RICHARD KARN MAKES HIS MINUTES AS MR. FIX-IT COUNT ON ‘HOME IMPROVEMENT’

Richard Karn seems like a regular Joe munching a hamburger with all the works at the patio commissary at Disney Studios during a rehearsal break from ABC’s “Home Improvement.”

In fact, he’s not too far removed from Al Borland, the character he plays on the enormously popular Tim Allen sitcom. Borland is the stoic, bearded, flannel-shirted assistant of fumbling Tim Taylor (Allen) on “Tool Time,” the show-within-a-show on “Home Improvement.” After watching him for two seasons on the Top Five series, fans are beginning to take notice. Karn confesses, though, that he’s usually oblivious to their recognition.

“It’s not something that’s on the front of my mind yet,” explains Karn, who toiled for 11 years on and Off Broadway as well as in regional theater before he landed the role of Al. “I still feel like no one knows who I am. I still feel anonymous.”

But the gregarious actor knows he can’t remain anonymous for long. Recently, the Seattle native got a taste of fame while at a Florida airport. “My plane got canceled, so I had to change to another plane. The lady at the counter was beaming as I was walking up because she knew who I was immediately. She said, ‘Could you sign this? My husband loves your show.’ ”

Suddenly, Karn found himself surrounded by 40 cheerleaders, also waiting for a flight, who spotted him. “It was the weirdest feeling. I felt like birdseed. They were all around me.”

Though Karn’s screen time is less than 10 minutes a week, he makes the most of his scenes with Allen. Karn believes Al’s appeal lies in his being an underdog.

“His ethics are in the right place,” Karn says. “He’s an innocent, which you don’t get a lot on TV. I’m trying to make him as real as possible so he comes to things with a lot of naivete.”

And Al is good at his job. “I think people appreciate that too,” Karn says. “He’s someone who does his job well but is not prideful about it. He’s not egotistical about it. He does his job. That’s how he was brought up. People like to say he should be the star of the show because he knows what he’s doing.”

Next season, Karn says, Al’s role will be expanded. “I think they are going to bring in things that arc--things about my character, about Al’s relationship with Tim and Pat and maybe even Wilson or the kids or his girlfriend,” Karn says.

“This year, we brought up things like I am building a log cabin,” Karn says. “We mentioned it once and we never went back. We have had Al with a couple of different girlfriends we have never gone back to. We have gone on to the next show. So we are going to have things that people will keep going back and seeing, which I think will be really nice.”

Originally, Karn was hired to fill in for the actor cast as Tim’s assistant on the pilot of “Home Improvement.” “They had cast another actor who was older,” Karn says. “He was a little taller and gangly, more physically different, balding, older and more irascible. A kind of guy who every time Tim screwed up, his ulcer flared.”

That actor, though, got a movie part and couldn’t do the pilot. The producers, whom Karn met at a writers’ conference in New Harmony, Ind., asked him to play Al for the pilot. Fate stepped in when the other actor bowed out of the series.

“I found out later because that other actor got a movie, they called me in because they knew I was a nice guy,” Karn says. “They knew I wouldn’t put up a big stink about doing the pilot and having someone come in and do the series.”

“I don’t think so” has become Al’s anthem. “The ‘I don’t think so’ line was a throwaway line the writers wrote to follow Tim’s joke,” Karn says. “I took it and made it more important than it was. I unknowingly took a one-dimensional thing off the page and made it into a three-year relationship behind the one line.”

Perhaps Karn’s so believable as Al because his father happens to be a successful builder. “My dad’s like a local celebrity now,” Karn says with a warm smile. “All of the lumberyards and hardware stores that he’s worked with his whole life in Seattle know that he’s Al’s dad.”

The downside of achieving popular success after years of struggle is the fact his mother, who died in 1983, never got a chance to witness it. “She saw me in a lot of plays in Seattle and summer stock,” Karn says softly. “But I wasn’t able to have her be proud I finally got something really good.”

Karn’s father has finally stopped fretting over his son’s welfare. “He wouldn’t let me know it, but there was a really heavy worry--’What if as an actor you don’t make it?’ I think every father is going to feel that. When I told him about this job, he was like ‘Great. That’s nice.’ It wasn’t until he actually saw it on television that reality kicked in. Then as the show got more and more popular, I saw this great relief come over him.”

“Home Improvement” airs Wednesday at 9 p.m. on ABC.