This 59-year-old’s lucrative side hustle: Earning $16,000 a month selling recycled fire pits on Etsy

In March, he moved the side hustle online, opening an Etsy store. He brought in $50,000 over the next five months, according to documents reviewed by CNBC Make It. In June, his highest-earning month to date, he made $16,000 selling fire pits, most which are priced between $600 and $1,700.

"It's tough for everybody right now and I thought, 'I can make some extra income and have fun doing it,'" Riegel tells CNBC Make It. "The fun is the magic of the whole deal. September through December, I pretty much saturated my hometown with fire pits."

Here's how Riegel started his unlikely business, and his plans to make it more financially sustainable:

Riegel, who oversees domestic suppliers for a furniture company during the day, says his full-time gig taught him the art of navigating e-commerce platforms. He'd previously used Etsy to source new designers and inspiration.

"At first, I thought [Etsy] was just a bunch of old women sewing quilts," he says. "Then I realized I could use it to see what's out there, who's being creative. The [small] companies that are just about to break [into industries] usually start off on one of these platforms."

Riegel is also a welder — he used to restore cars as a side hustle and took vocational welding classes in 2006 — and says working creatively is cathartic, even if his side hustle adds 40 extra hours of work to his schedule each week.

The idea came from a friend who made a similar fire pit from a propane tank end. It took trial and error to perfect the bronzed and customized versions Riegel now sells, he says. He wanted his fire pits to last longer than the ones sold in big retailers, which he says are "flimsy" and "meant to last maybe two years."

So, he bought some scrap metal from a nearby seller and started experimenting with different legs and feet for the fire pits. "The first couple were pretty bad, but the good thing about metal is you can just cut it off and redo it," he says.

Riegel says he spends about seven hours per month just sourcing the metal, which is becoming increasingly expensive. His profit margins are typically around 35% to 40%, but he only keeps about half of his proceeds, reinvesting the rest back into his side hustle, he says.

Currently, Riegel only has one employee: He pays his 79-year-old father, Terry, $15 per hour to help recycle the tank ends and coordinate freight schedules. The 250-pound fire pits can't be easily shipped through FedEx or UPS, and Riegel's father helps maintain constant contact with the trucking companies that carry the products throughout the U.S. and Canada.

The size of the products limits Riegel's ability to ship them out: From March through July, he only got 60 fire pits onto the road. The further away a customer is, the more expensive shipping is — Riegel estimates an average shipping cost of $375 per order — so he only sends out a couple fire pits on freight trucks at a time.

Etsy's shipping partners are costly for small-business owners who sling a low volume of product, he says. So, he leans on other sellers, who tell him which carriers are most effective for small businesses like his. He says he works with several private carriers to meet his shipping needs, primarily Estes and Unishippers.

However, Etsy does help Riegel substantially with advertising and search engine optimization, he says. He pays about $200 extra per month to advertise through Etsy — which he says is less than comparable rates on Wayfair and Amazon Seller Central.

He also doesn't mind reinvesting so much of his profits back into the side hustle, he says — at least for now. Currently, that money is going toward figuring out how to add gas lines, shrink production times and experimenting with new products like chimineas, a type of freestanding fireplace.

As for the money Riegel has kept, he's spent some of it on another important endeavor: his daughters' weddings.

"Having [extra money] definitely helps," he says. "But more than anything, it's really just seeing what I can do with this business and drive it forward."

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