Greg Amundson spent about 30 years building custom wood-framed houses near Lutsen on Lake Superior.

That career came to halt a decade ago, during the Great Recession of 2008-2009, when he was caught holding three high-end houses he had built on speculation, just as buyers disappeared.

Amundson, 58, salvaged the housing business by turning into a rental manager.

A longtime garage tinkerer, Amundson decided to start his next business by inventing an alternative to caulking. The process, which can be messy and imprecise using a caulk gun, had always bedeviled him. It often “looked like a monkey installed it,” Amundson recalled.

So one night, while lying in bed and worrying about his housing business, Amundson’s thoughts drifted to caulk. There must be a better way.

“I tried to come up with an easy, professional-looking design that would allow anyone to use it and also look perfect when installed,” he recalled. “The ‘wedge-shaped’ idea surfaced about 4 a.m. … and I started drawing. I did not sleep the remainder of that night because I felt like I came up with something exciting.”

But coming up with an idea is only part of the equation. “Another key part of this was my search for an extruder who would work with an inventor,” Amundson said. “Most are reluctant, since inventors can be expensive and time consuming. Gary Noble at Bio-Plastic Solutions in Blooming Prairie was intrigued. We would not be where we are at if not for his help.”

Amundson began selling the product as EasyCaulk on Amazon in 2013. Sales were slow. He attributed it to having the word “caulk” in the name, stirring up memories of bad caulking experiences for do-it-yourselfers.

Betsy Amundson, the marketing director and Greg’s wife, suggested the name change. In early 2016, Amundson re-branded the product as InstaTrim. Sales escalated.

It took several years and about a half-million dollars from savings and retirement funds over the years, plus two patents and the name change, but Amundson expects to expand (mostly online) sales to $400,000 this year from about $325,000 last year.

“We just went on Walmart.com,” Amundson said. “Every day, we wake up and run to work [from the house to the garage]. It’s a challenge to stay on top of it, but it’s all good.

“We never, ever gave up. This is not like TV, where things just happen. It’s been a long process. The odds are always stacked against you. It’s been tough on the family and finances. But it’s the coolest thing I’ve ever done, without a doubt.”

By changing from EasyCaulk to InstaTrim, Amundson believes he entered a less-competitive niche market for trim in bathrooms and around the house. “Sales increased fivefold the month we changed the name,” Greg Amundson said. “We hit a nerve. There’s a lot of cheap caulk strip made in China that’s out there. We have a better product that works. It’s environmental, and anybody can use it.”

InstaTrim is sold as two 10-foot rolls for $19.95 and comes in six colors. That’s more expensive than typical caulk tubes. “It will save you a lot of time and it always goes on perfectly,” Amundson said. “You’re not buying a caulking gun and wetting a finger … and it’s permanent and won’t get moldy as it solves cracks and gaps. It’s a better value, if you factor in time, quality and longevity. And how many half-filled, partial tubes of caulk does everybody have in the garage — that end up in a landfill?”

Amundson said InstaTrim adhesive trim strips are a healthier alternative to caulk that doesn’t require curing, so there are no toxic and smelly fumes. The product also leaves little waste and the packaging is recyclable.

Amundson’s first wife died three years ago. Betsy was a family friend — and an independent marketer who became interested in the business.

Greg Amundson was driven to make the business work in memory of his first wife, who did not see much return on their initial effort.

“I really needed to make this business something for her,” Greg Amundson recalled. “I think we are in our seventh year with this business. And the last three years have been exhilarating.”

“Particularly when you get a life-changing e-mail from Walmart or a window manufacturer for a made-in-Minnesota product,” Amundson said.

InstaTrim is manufactured at Bio-Plastic and shipped from the Amundsons’ operation in Scandia. “For me, a semi-moron in a garage, this is my idea and now, I kind of get to play with the big boys, along with my wife,” Amundson said. “We’ve been fortunate and we’re trying to be smart.”

Amundson said he tries to pay forward some of his recent good fortune by mentoring a military veteran through Bunker Labs in Minneapolis, a nonprofit organization that provides support to veterans who are inventors and entrepreneurs. He also donates his product to Operation Honor, an organization that makes flag cases to house the flags given to the families of fallen soldiers.