Mark and Cathy Welna took a big risk when they built an expanded Welna Hardware at 25th and Bloomington Avenue S. 15 years ago in an inner-city neighborhood that had seen lots of homeowners and businesses head for the suburbs since the 1960s.

They sold the old building across the street that had housed Welna Hardware for two generations.

It was started after World War II under Mark's late grandfather and his dad, who died last year at 89.

Mark's parents, Virgil and Pat, knew something about six-day weeks at the store as they also raised three kids in south Minneapolis. But they worried about their expansion-minded son who had bought the old hardware store from them years before.

"We put everything on the line," recalled Mark Welna, who also pledged his and Cathy's savings, mortgaged their house and businesses to raise the approximately $1 million to finance the new Welna Hardware and repair business.

It worked.

Sales have more than doubled at Welna Hardware, one of the commercial bastions of the working-class Phillips neighborhood, which has seen significant commercial and residential investment in the last 15 years.

"It's a good, profitable business," said Mark Welna, who still works six days a week.

The hardware store's customer mix has changed over 60 years, from mostly whites of German and Scandinavian heritage to a mix of white, black, American Indian, Latino and East African immigrants in the diverse neighborhood.

Mark Welna, who tries to remember every customer's name, said his business has benefited from the neighborhood renewal.

"They are all doing us a favor when they come into our store," he said. "Our approach always has been to kill the customers with kindness."

And now Welna, 59, has taken his winning inner-city model to the suburbs.

In late 2017, Mark and Cathy, who often worked at Welna Hardware when she wasn't at her nursing job or raising their kids, acquired the Robbinsdale Ace hardware from a retiring owner.

It was a tired business in an inner-ring suburb that is seeing rapid change.

Once again, the Welnas have raised something approaching $1 million to buy the business, expand and renovate the store, expand product lines and inventory. They sold their south Minneapolis home to help finance the effort.

The formula seems to be working

"Our business was up by 50 percent in 2018 over 2017," said Mark Welna. "And we really didn't get going until May. Our customer counts and volumes are way up.

"We expanded in almost every area. We bought a forklift. This store used to order salt by the bag. Now we order by the pallet, 100 bags of salt at a time.''

The Welnas are planning to move to a townhouse in Robbinsdale. They like its growing downtown.

A mix of younger, more diverse residents have moved into the area, a few blocks from North Memorial Health Hospital and close to Victory Memorial Drive, the north Minneapolis parkway.

"It's starting to look like [Nicollet Avenue's] Eat Street, around here," quipped Mark Welna, ticking off a list of Robbinsdale eateries.

Welna Hardware sells a lot of small-ticket electrical, plumbing and other goods as well as high-end cooking grills that can run $1,000.

"The Welnas brought another family-owned business that fits perfectly in our small-town flavor," said Marcia Glick, Robbinsdale's city manager. "If they don't have it in their store, you don't need it.

"They can help you with anything and they've expanded into the old paint store [next door]. They fix windows in the basement."

Rolando Diaz, 36, an immigrant who owns Marna's Cafe next door to Welna Hardware, worked his way from dishwasher to chef at several Twin Cities eateries over a decade before opening his own business.

Diaz and Mark Welna, who drank Costa Rican coffee at Marna's during my visit to downtown Robbinsdale last week, share a lot of the same customers. Marna's, which caters 120 events annually, has expanded its restaurant menu and hours recently.

Downtown Robbinsdale boasts several locally owned eateries and pubs, as well as a Wuollet Bakery. A Hy-Vee grocery just opened several blocks from downtown.

"Robbinsdale is a good place for our business," Mark Welna said over coffee.

Welna doesn't plan to work six-day weeks forever. The long-term family aspiration is for two of his three kids who work in the business, Sam and Molly, to buy out their parents and carry on Welna Hardware into the fourth-generation ownership.

Mark's brother Jim, a retired police chief, owns and runs a third Welna Hardware, in Minneapolis' Seward neighborhood.

Neal St. Anthony has been a Star Tribune business columnist and reporter since 1984. He can be contacted at nstanthony@startribune.com.