"I told him, 'You better work your butt off to take care of her,' " Barlow said.
Merck did, often finding side jobs for extra money, even if it meant working all day, then taking on a second shift at night. It was more than just providing for his family. It was a promise.
Commitment was a theme that ran through the Merck's life -- to family and friends, to his love of anything automotive, and to his country.
His love for the military would lead him to rejoin in 2003, fully aware he might be heading to war. He would die two years later in Iraq, killed by an accidental weapons discharge.
MERCK NEVER MISSED a chance to combine two of his loves: fixing cars and helping people.
On countless occasions he would roll out of bed at 2 a.m. to help a friend stranded on the side of the road. Once he drove more than three hours to fix his mother-in-law's car, then drove back home to make it on time for work.
His generous spirit was a natural part of him, family members say. Learning to fix cars was a lifelong pursuit, but he got an early start helping his dad, a mechanic for Georgia Power. He grew up under the hood, getting his hands dirty with the cars under repair behind his house.
His sharp, detail-oriented mind made him a whiz at auto repairs -- even when he wasn't under the hood. A friend called him once from the side of the road with a broke-down vehicle. Merck diagnosed the problem over the phone, then talked the friend through the repairs.
He made it through two years of college before dropping out; he preferred the garage over the classroom. So he found the ultimate outlet for his passion, joining the Army in 1990. He worked on diesel vehicles for 12 years, rising to the rank of staff sergeant.
Along the way, he used his skills to help his comrades. A brief stint working on refrigerated trucks earned him a lot of friends during a relief mission to Haiti in 1995. He rigged two refrigerated trucks to run on a generator so the troops could have relief from the tropical heat.
He retired from the Army in 2002 to allow his family to settle down, but his patriotism never took a break. One of the first things he ordered for his front yard when he moved into his last home -- in Evans -- was a flagpole for the front yard.
"It was very important to him," said his father-in-law, a Vietnam veteran. "We both felt that it was by the grace of God that we were born American."
FAMILY WAS IMPORTANT to Merck. Weekends were always reserved as family time for him, said his wife, Tanya.
Every weekend he was at the grill trying something new, she said. Some of his efforts surprised her, like the time he successfully grilled a pot roast. There were also some spectacular failures, including a London broil drizzled with molasses.
"It was disgusting," Tanya said, smiling at the memory. "It hurt his feelings, but I told the kids they didn't have to eat it because I wasn't going to."
Sunday afternoons were dedicated to stock car racing. Friends and families cracked open beers and spread out over couches and floors to watch a race. Kids raced through the house playing.
By the end of the day, "my house was a total disaster," Tanya said.
The two of them got to know each other when they were teenagers, dating at Stone Mountain High School in 1984. He would tell people she was attracted to him because of his sports car. But Tanya said it was her future husband's respect and polite manners that drew her to him.
His parents are "definitely down-home Southern people," she said.
When Tanya got pregnant before they got married, she left it up to him to break the news to her father. He did so from under the hood of a car.
The three children she had with Merck share character traits that remind her of him. Nick, the oldest, is an engineering major at Georgia Tech. He's meticulous, always ironing his clothes and paying attention to detail. He shares his father's love for cooking.
Her daughter, Mackenzi, is quirky and always cutting up. Her humor is in line with her father's, and she looks the most like him.
The youngest, Jake, is the quiet, somber type and as nonconfrontational as his father. If his mom gets on to him about something, he'll take the grief and simply reply: "OK, I'm sorry. I won't do it again."
His father also didn't like to argue, Tanya said.
"He would let me say what I wanted, then go on with life," she said.
THE LAST TIME Merck saw her husband was before he deployed from Fort Drum in New York in 2005. He had enlisted in the Georgia National Guard two years earlier, a year after he retired from the Army. He yearned for the structure, the work ethics drilled into him and the leadership roles he had absorbed with his duties.
"He had a really hard time getting adjusted" to civilian life, Tanya said.
She had been able to scrape up just enough money to go see him off, but her children couldn't make it. Just before they said goodbye, a tremendous sadness came over her that she couldn't shake.
"I feel like this is going to be the last time I see you," she told her husband.
He dismissed the idea but, still sensitive to his wife's tears, told her, "Well, then don't let the last time I see you be with tears on your face."
Merck wiped her eyes, looked at her husband and gave him a little smile.