Two of the chief contenders for the D.C. Democratic mayoral nomination, City Council Chairman Sterling Tucker and council member Marion Barry, took their campaigns to the opulent Homestead resort here this weekend, but found the problems of rent control in Washington had followed them.

Both Tucker and Barry came to this Allegheny Mountain spa looking for votes and campaign contributions at the annual convention of the Washington Board of Realtors and the Mortgage Bankers Association of Metropolitan Washington.

What they largely encountered was uniform hostility toward the District's rent control law limiting landlords' profits to an 8 percent return on their investment.

Barry called the law a "BandAid" solution to the problem of rising rents in the city and Tucker described it as a "short-range disincentive." But both said in speeches yesterday to the two groups that the law was necessary and that they would continue to support it until more rental housing is built in the city. But neigher suggested how soon that might be.

The third major candidate in the Sept. 12 primary, Mayor Walter E. Washington, who did not appear here, has also said that rent control "is needed for the time being."

The realtors and mortgage bankers voiced skepticism at Tucker's and Barry's suggestion about a potential end to rent control and reserved their loudest cheers and applause for R. Robert Linowes, a zoning attorney and president of the Metropolitan Washington Board of Trade.

Seated between Tucker and Barry on the dais, Linowes told the two politicians: "You've got a credibility problem. You can't get any lender to come into the District when there is no certainty what's going to happen" with rent control.

Linowes suggested that the housing industry and the D.C. government set a timetable for building a specific number of new housing units, at which time rent control would end. Although Linowes mentioned no number of units or the time for completing them, both Tucker and Barry said they agreed with the concept.

Tucker and Barry depicted Mayor Washington, their chief rival in the race, as a "good man," but one who had been an ineffective mayor and largely to blame for the bureaucratic snarls in the District government that many of the business executives here complained about. Barry also said Tucker shared in that responsibility as part of what he regularly calls the "Washington-Tucker administration." The two ran together four years ago.

"It's unfortunate that the mayor, for whatever reasons, decided not to come" to the convention, Barry said. "It shows once again his indecisiveness and vacillation."

The mayor was invited but his campaign manager Lacy Streeter said there was no need to travel the 200 miles to Hot Springs. "The election is being conducted in the city," Streeter said. "The voters are here in Washington."

Despite the time away from the campaign in the District, both Tucker and Barry said their trips had been worthwhile politically. They were flown here with their wives for the 19-hour stay and the $175 air fares and $140-a-night hotel tabs were picked up by the realtors' group.

The realtors and mortgage bankers have been holding morning meetings here since Thursday. But the afternoons and evenings have largely been devoted to the play-time activities this resort is famous for - tennis on 15 courts, golf on three mountainous courses, swimming in spring-fed pools, concerts by a trio dressed in tuxedos at the afternoon tea in the hotel's grand foyer and dining at dimly-lit tables in the evening.

Although some executives said they will find the business contacts they meet here useful when they get back to Washington, the convention, as much as anything, seemed an excuse to have a good time away from the office. One realtor and Barry supporter, Jeffrey N. Cohen, relaxed beside the tennis courts Friday afternoon sporting a red baseball cap with a Donald Duck figure and wind-blown propeller on top.

The liquor for 450 business executives and their spouses was largely supplied by several corporate members of the two groups, which convened daily at morning and evening cocktail parties. In addition, 140 businesses belonging to the two organizations contributed $11,000 worth of prizes - cash, liquor, Redskins tickets, mopeds and assorted other items - that were given away in regular drawings.

Both Barry and Tucker concentrated on politicking in their brief stay. They chatted amiably with conventioneers at a predinner cocktail party Friday night, later that night at a boisterous "liqueur reception" and again at a late-morning "whisky sour party" after the speeches yesterday.

Tucker already has received substantial contributions from realty interests in Washington, although Board of Realtors President James R. Ingham Jr. and others said the housing industry in the city is split fairly evenly among the three major candidates. Ingham said the group is creating a political action committee to dole out more money and hopes to raise between $5,000 and $10,000.

Tucker was fairly reserved in asking for money here, saying he would leave the fund-raising pitches to real estate executive Raymond J. Howar, one of his biggest financial boosters, after Tucker left the convention. Tucker said no one contributed any money to his campaign while he was here.

Barry, however, missed few opportunities to encourage convention-goers to give money for his mayoral bid, handing out envelopes with his campaign address stamped on them at the slightest hint that someone might be a potential contributor.

At the end of his speech yesterday, he told the crowd, "I have some cards over there with my wife. Send me some money. I'm not bashful about these things."

He said later that he had been given "several hundred" dollars for his campaign while in Hot Springs.