Just in time for summer, a scrappy Minnesota inventor and a St. Michael industrial manufacturing pro have teamed to make leather flip-flops with interchangeable messages built right into the sole.

Sand Traxx Footwear and Jet Edge Inc. are daring beachgoers to have fun by littering the sand with a host of personalized messages imprinted simply by walking on the beach.

The sandals, now priced at $45 a pair, feature an empty recessed slot on the bottom of the shoe that can hold up to 10 embossed rubber letters.

The letters, to be made in China and finished by Jet Edge’s powerful water jet machines in Minnesota, can be arranged to form words. When worn on the beach, the soles imprint the user’s message with every step in the sand.

Insert mental picture here of “Marry Me?” “Go Delta!” or “Vikings!” printed in sand and one gets the idea for endless beach fun.

“I got the idea for Sand Traxx after watching an episode of [the TV show] ‘Shark Tank,’ ” said Jeffrey Wagener, who farms sod in Waconia. “A person had flip-flops with a saying embossed on the bottom. I thought that was OK, but wouldn’t it be nice if a person could personalize their message?”

Jet Edge co-owner and President Jude Lague first heard about Wagener’s idea while at a “local watering hole.” Intrigued, he soon had Wagener inside Jet Edge’s factory and meeting with his marketer, industrial-cutting expert and even his patent attorney.

Soon they had a prototype shoe, cut with water jets pumping at 55,000 pounds of pressure per square inch. “The velocity of the water stream travels at the speed of sound. It leaves a really nice edge,” Lague said.

Jet Edge is a 32-year-old design and manufacturing firm that specializes in industrial waterjet systems that precision cut, prepare surfaces for treatments and remove coatings. Customers include airline and auto companies as well as industrial manufacturers, machine and job shops.

Lague said his investment in Sand Traxx is just a few thousand dollars of time, salaries and materials, but it will be worth it if his new friend Wagener eventually buys his own Jet Edge water cutting machine. Prices start at $70,000.

“That’s a lot of shoes,” Lague concedes. “But I think he has come up with a great product. It’s something that can sell. And it’s fun. If his price point is low enough, people will buy a pair just to get some laughs when they are walking around Florida on the beach. He still has a couple of hurdles left, but he has a product that people will want if they are aware of it.”

Wagener’s idea is to give Sand Traxx wearers versatility so they can express themselves without saying a word. Beach walkers customize messages by simply changing out the rubber letters securely Velcroed into the recessed slot on the bottom of the sole.

“It’s kind of a new, interesting concept to be able to change the letters on the bottom of a shoe,” said Nancy Lauseng, Jet Edge spokeswoman. “It’s kind of fun.”

Wagener found a manufacturer in China to make both the shoe and large mats of embossed rubber letters.

Once the materials arrive here, Jet Edge machines are expected to cut apart all the letters, followed by Wagener doing the final assembly in Waconia.

Each pair of sandals sold will automatically come with two sets of alphabet letters, eight spaces and two sets of the characters 1, &, #, $, ? and the heart symbol, so owners can have fun stomping out social media-type messages.

Each rubber letter and character will be nearly a half-inch thick.

Wagener hopes to be in full production soon.

To get there, he’s trying to raise $10,000 through a crowdfunding campaign he launched last month at www.indiegogo.com. The money will help perfect his character molds and begin production, he said.

“I should have product in a couple of months,” he said. Appearances at U.S. trade shows should follow.

“I will push as hard as I can to get the product as big as I can,” Wagener said.

He said he is now talking to Minnesota-based retailers and distributors about getting the product out on shelves.

While competitors make sandals with cute message on the soles, “nobody has anything like this,” he said.