CARROLLTON, Ga.—In a classroom of a technical college an hour from Atlanta, Kimberly Hinely picks up a welding torch and lowers her face shield. Sparks fly around her as she melts the metal, joining iron to iron.

Three months into an evening welding program where she’s the only woman, the 44-year-old former tattoo artist said she feels like “one of the guys.”

“I don’t like working with women—their drama,” she said. “I’ve always gotten along with guys well. I’m a real smartass.”

When she finishes the certificate program at West Georgia Technical College next year, Hinely will be trained in a field the Bureau of Labor Statistics says pays $40,000 a year, money that will help support her four kids, aged 7 to 25.

During the last academic year, U.S. colleges and trade schools awarded nearly a million certificates, almost 60 percent of them to women. Yet just 6 percent of those in welding—the most popular program among men—went to women.

So where are all the female students? They’re in the salon next door, learning about cosmetology, and in the nursing classroom nearby, administering “rag baths” to mannequins. And when they graduate, they’ll earn barely two-thirds of what Hinely stands to make, according to the Bureau of Labor Statistics.

At a time when there is an acute shortage of welders and other tradespeople, hardly any women are being trained for these and other well-paying jobs. This more than 40 years after Congress banned sex discrimination in American education.

Experts offer several reasons for this split, including gender stereotypes and the threat of workplace harassment in male-dominated jobs.

But employers and advocates agree it’s hurting both women and the economy, leaving families stuck in poverty and businesses scrambling for workers in fields, such as IT and advanced manufacturing, where they’re growing troublingly scarce.

So-called middle-skill jobs, such as welding, automotive repair, cosmetology, and medical assisting, account for 53 percent of United States’ labor market, but only 43 percent of workers are trained to the middle-skill level, according to 2015 data from the National Skills Coalition, the most recent available. Middle-skill jobs require more than a high-school diploma but less than a bachelor’s degree.

Getting more women into nontraditional certificate programs could help lift more families into the middle class and ease a labor shortage that is expected to only grow worse as more baby boomers retire. Yet not much is being done to change the enrollment pattern.

“We’re missing something obvious that would help employers and help the economy,” said Barbara Gault, the executive director of the Institute for Women’s Policy Research.

Women make up 55 percent of middle-skill workers, but 83 percent of those in jobs that pay less than $30,000 a year, according to the Institute for Women’s Policy Research. And the median wage for women with a certificate is $27,864, compared to $44,191 for men, the Georgetown University Center on Education and the Workforce reports.

Much of that gap is due to occupational segregation —women clustering in low-paying careers including cosmetology and child care and men in more lucrative professions such as welding and automotive repair.

There’s been some progress. Before the passage of the Title IX gender-equity law, in 1972, there were almost no women or girls in vocational programs leading to careers in fields dominated by men.

Today, women and girls make up about a third of students in so-called nontraditional vocational programs—those in which three-quarters or more of the workforce is male.

But many certificate programs are still dominated by one gender to a surprising extent. Ninety-four percent of welding certificates went to men in the last academic year, and 95 percent of cosmetology certificates went to women, an analysis of data provided by the U.S. Department of Education shows.

In some high-growth, high-paying programs, such as information technology and advanced manufacturing, the share of women and girls is smaller than it was a decade ago, according to the National Alliance for Partnerships in Equity.

Title IX made it illegal for schools to steer students into particular fields based on their gender, and required institutions to ensure that disproportionate enrollment was not the result of discrimination.

In the 40 years since it passed, the nation has spent millions encouraging girls and women to pursue degrees in science, technology, engineering, and math. Fewer resources have gone into persuading them to trade their blow dryers for welding torches, however.

In the 1980s, and 1990s, Congress required states to set aside a share of their federal job-training funds to eliminate sex bias in career and technical education. But policymakers eliminated most of those rules in 1998, replacing them with a requirement that states increase participation and completion rates for both men and women in programs where they’re underrepresented.

Congress added teeth to that law in 2006, threatening states with the loss of federal funds if they failed to meet specific targets. So far, though, no states have been stripped of their funds despite the fact that only six states have consistently met their targets since the law was enacted.

In addition to recruitment methods that favor one sex, career counseling that channels students into stereotypical fields, and fear of sexual harassment, the biggest contributor to the gender divide in certificate programs may be socialization, said Mary Alice McCarthy, the director of the Center on Education and Skills at the New America Foundation.

Even today, “men are much more sensitive to salary signals then women,” McCarthy said. “It goes deep into our understanding of our roles as caregivers or providers.”

Over in the cosmetology classroom, Kaylie Hudson, 31, was giving a bob to a brown-haired mannequin with a mullet while other students practiced their skills by giving discounted haircuts to locals. She said she hadn’t given much thought to how much she might earn as a hairdresser. Her dream is to open a salon that would give cut-rate cuts to low-income women “so they feel better going into job interviews.”

In fact, with her certificate in cosmetology, she’s likely to earn less than the average high-school grad, according to the Georgetown center. That begs the question of why women would pay for certificate programs—even taking on debt to do it—to end up with little to no earnings boost.

For Lorelei Shipp, 44, who is cutting her friend’s hair in the salon next door, it’s about freedom and flexibility. As a hairstylist, she expects to make half what she earned as a customer-service manager in the corporate world, “but the work-life balance will more than make up for it.”

DeeDee Patterson, an instructor in the cosmetology program, can count on one hand the number of men she’s taught in the past eight years. She said male hairdressers are in high demand because “women want to look good for men, and men know what looks good on women”—and often out-earn female colleagues. But just as women are afraid they’ll be perceived negatively by co-workers in male-dominated fields, men considering cosmetology “are afraid they’ll be stereotyped as too feminine.”

The median salary for male cosmetologists is $39,100, according to the Georgetown center; for women, it’s $24,700.

Students who break with gender norms are often following family members into a trade. Brandon Harris, 19, the only man in the nurses’ aide course, has a mother and aunt who are nurses. Channa Cassell, 18, one of three women in the morning welding course, has welding in her blood: Her father, uncle, and grandfather are all welders. Even so, her family was “a little shocked” when she announced that she would follow in their footsteps.

Parents often discourage their daughters from going into welding, seeing it as “dark, dirty, and dangerous,” said Monica Pfarr, the executive director of the American Welding Society Foundation. In an effort to change that image, the foundation has started sending a tractor-trailer truck to state fairs with an exhibit inside promoting the highly technical, well-paying jobs available to welders. The trailer gets 28,000 visitors a year, she says.

In west Georgia, the community college and local employers recently tried another tack, holding an open house for aspiring tradeswomen. Carroll County, where the college is located, will need to produce 4,000 more graduates of all kinds by 2020 to meet employer demand, and it won’t get to that goal without women, said Donna Armstrong-Lackey, the senior vice president of the Carroll County Chamber of Commerce.

“We’re trying to take away the element of fear that they’re not qualified, or don’t have the strength,” to do traditionally male jobs, Armstrong-Lackey said at the open house.

But it can be a tough sell. When Armstrong-Lackey asked one petite young woman if she was considering a career in welding, the woman quickly responded, “I’m too little.”

Armstrong-Lackey told the woman that her own daughter “is your same size and she’s getting a welding certificate.” She urged: “Don’t discount it.”

Across the hall, Nikki Bond, 32, was chatting with the West Georgia Technical alumna Andrea Laminack, 39, about what it’s like to be a woman welder. Bond, a mother of three, had already registered for the certificate program in welding, but was nervous and seeking reassurance.

Laminack, who is pregnant and has a 14-year-old daughter, told her there will be challenges, but to focus on her love of the work.

She said she was picked on by male colleagues when she started her job. They’d leave notes on her welds with insults such as “ugly,” and “due in 2020,” a reference to what they considered her slow pace.

“I had to grow a thicker skin, but I’m providing well for my family,” she said. “The money keeps me from running away.”