Ron Wellman, 56, Army veteran, diehard Republican and Pennsylvania maintenance worker, stood near the Washington Monument yesterday, getting ready for the Solidarity Day rally, his Western-style string tie flying in the breeze, and a plaid polyester jacket on his back.

Wellman was a long way from home, home being near Erie, Pa., just outside Edinboro State College where he shovels snow in winter and cleans up the school grounds in summer to feed his family.

When America picked a president last year, Wellman voted for Ronald Reagan because he was "l00 percent" for a stronger national defense. Wellman said he wanted to see the Russians put in their place and lazy Americans taken off welfare. But now Wellman says he is perplexed.

All he says he sees coming from the Reagan admininistration is that "the poor people, the little people, are getting ripped off, and this administration is favoring the rich."

Just this complaint brought Wellman and thousands like him to Washington yesterday -- people who work on assembly lines, sew clothes, pick crops, transport food and clean streets and government buildings -- to tell Reagan that the little people still form the backbone of this nation and that they are being hurt.

Even from those who had once enthusiastically supported Reagan, from burly steelworkers and young Latino busboys to elderly ladies who place the union label on thousands of garments each year, the message was clear.

"We got sold out," said Thomas Ramsey, a sugar hauler who had traveled all night Friday by bus from South Bay, Fla., with 46 fellow sugar industry workers to particpate in the Solidarity Day protest.

Ramsey says he remembers vividly the television ads during the presidential campaign last year that highlighted Reagan's years as a union organizer for the Screen Actors' Guild, and now he says he resents the fact that most of the benefits of Reagan's tax package will go to the wealthy.

"He's taking bread out of the mouths of the American people," said Ramsey, who has a wife and two children. " . . . If they want to cut the budget and fix everything up in the economy, why don't they start with the politicians. Some of them are making $80,000, $90,000 a year and they ain't doin' anything. Me, I work seven days a week, l2 hours a day in our busy season from October to March, and I'm makin' $17,000 a year."

Though Ramsey is only 30 and far from retirement age, he wore a red, white and blue sign that said, "Organized Labor is Opposed to Social Security Cuts."

But bricklayer Ernest DiFranco, 61, of Pittsburgh, is close to retirement and doesn't like Reagan's proposal to cut benefits sharply for people retiring in the future at 62 instead of 65.

"I've been picking up bricks every day of my life for 40 years," said the silver-haired DiFranco, son of Italian immigrants. "I don't want to work until I'm 68 or 70. I might not make it. I might be six feet under by the time I get to receive my benefits. My back is broke now," he added as he joined a crowd of miners and state and municpal employes boarding a Metro train at RFK Stadium.

"I paid into Social Security for 40 years; it's mine, not his," said 68-year-old Woodrow Wellington, a retired maintenance man from Newark, Del., as he sat in the shade by the Washington Monument in a ten-gallon hat and cashmere jacket. Wellington, who carries his AFL-CIO lifetime membership card in his pocket and calls himself a "hardline Democrat," said it irks him that Reagan often played up his past as a union organizer during the presidential campaign.

"He made out like he was this big labor person. But I don't think he ever done much work but play with that toy pistol on Death Valley Days," Wellington drawled.

Many other protesters yesterday voiced concern about Reagan's various deregulation proposals, especially those that they say would severely weaken the occupational safety standards.

For evidence, Bill Haynes, a Long Island, N.Y., painter, shows his wrists. They have been burned red and are peeling from constant contact with paint removing chemicals, he says.

"A lot of us In the International Brotherhood of Painters and Tradesmen work in painting where we have to go on scaffolding, in sandblasting and handling toxic materials," said Haynes, who, like other painters, marched along Constitution Avenue wearing a hard hat. "Without OSHA Occupational Safety and Health Administration behind us, our jobs could become even more dangerous."

Many in the crowd, especially young blacks and Latinos, said they had benefited from federal job training and other government-funded programs, such as national defense student loans, and had provided commmunity service in return.

John Richardson, 30, had a Comprehensive Employment and Training Act job cleaning up trash from back yards and vacant lots and exterminating rats in tenements in New York City's Harlem. But this year, several of those jobs, including his, were abolished, he said, even though health problems in Harlem remain as severe as ever.

"You can't imagine how many cases there are of rats crawling into cribs and biting babies . . . . We were really needed," he said of the CETA workers. Many of them had been in the program as long as five years and some even got married thinking they would have a steady income. "But there's no security now," Richardson said.

As the afternoon wore on and the signs and banners were discarded and the crowd began to dwindle, many of those who had arrived in the morning full of enthusiasm, ended the day with mixed feelings about how effective their message had been.

"We should have been here during the week to shut down Washington," said Ron Weissen, president of a st wokers' local in Homestea Pa. "We came to show union support, but it's not going to change a thing, really."

But said John Patterson of Local l842 of the Machinists union in Pittsburgh, "If this march doesn't work, we'll be back again."