PROVINCETOWN — As Alex Hanelt closes up shop for the evening, he carefully removes the precious jewelry from each display case. Then he retreats to a little workshop in the back to catch up on repairs, engravings, and polishing.

Last week, as he sat fixing a watch, he talked about learning his craft from his father, Günter, who opened Exuma in Provincetown three years after he arrived from Germany in 1971.

Alex and his two sisters grew up spending their after-school hours at the shop while their parents worked. “I can’t remember a time when I wasn’t here,” Alex says of his father’s Commercial Street jewelry store. “I’m told I was running along the counters not long after I learned to walk.”

He remembers being most curious about the repair shop — “and all its machines and noises” — when he was a little kid. “My father would be soldering jewelry with the torch and saw that was something I was drawn to.” Early on, Günter taught Alex how polish rings and then to do engraving.

“But for me, it was hard to engage with strangers like he would,” Alex says. “When I was younger, I was a little bit more in my shell.” He remembers his father encouraging him to go out on the sales floor.

“ ‘Look at those people over there,’ ” Alex recalls his father saying. “ ‘Just go say “Hi” and that’s all you need to do.’ ” Alex says, “He was right, it was easy. You just say ‘Hi’ and people say ‘Hi’ back. The conversation starts from there.”

Alex started working full-time at the shop the summer after he graduated from Nauset High School. “I started when I was 18, and I’m about to turn 35 now, so it’s been 17 years,” he says. “Learning for me has been about watching my father at work.”

The son says his father was a patient teacher when it came to gaining technical knowledge about fine jewelry making and gemstones.

Günter says he doesn’t remember doing much formal teaching. Alex “learned by osmosis,” his father says.

His father is a learner, too, Alex says. “He’s one of those guys who likes to figure out how things work.”

Being in one place for so long is especially rewarding, Alex says. “I clean wedding rings for people who bought them 25 or 30 years ago.” Some of the people who come in talk about how long they’ve been coming to town. “They’ll pop in, and say, ‘Hey, does that German guy still own this place?’ And I’ll tell them, ‘That’s my father — he’s still here most days,’ and then they’ll launch into some story that they have about that one summer they worked here and had so much fun.

“I think it’s done a lot of good for our relationship, working together for all these years,” Alex continues. “I think that goes both ways.” Not that they don’t butt heads sometimes, he adds, which is only natural when you’re working together 40 to 60 hours a week.

What’s best about their work together, Alex says, is that “I’ve gotten to see the father I grew up with — and to know him more completely.”