Joan Mondale, the potter, had some expert criticism on her work yesterday afternoon at a reception at the Vice President's Residence.

Mondale, by request, showed a pitcher she had made to Otto Natzler, the dean of American ceramicists. "Wonderful work," Natzler said, caressing the pot, "but this handle is a bit weak. If it had flared right here . . ."

Joan Mondale entertained at the reception for the potters whose works are included in the Renwick Gallery landmark show, "A Century of Ceramics in the United States," which opens to the public today. Also attending the party were representatives of Philip Morris Inc., who with Miller Brewing Co., the New York State Council on the Arts and the National Endowment for the Arts helped pay the cost of the exhibition and the preview dinner.

"Most of our generation of potters have never seen the early works in the show before," said Betty Woodman, one of the ceramicists whose work is displayed. "I'm sure the show will make real changes in the way ceramics are made in the future."

Trying to explain one of Woodman's works, Mondale called for help from Garth Clark, who with Margie Hughto wrote a book about the exhibit. "Betty makes bogus functional objects," said Clark airily. "If you used them for dinner, you'd starve before you could eat. Like her four-foot-long asparagus server than only holds three stalks."

Mondale, who saw the show earlier yesterday, said she wondered how some of the great glazes were made. "The secrets are lost."

Donald Reitz, who makes hughe pots that are among Joan Mondale's favorites, also was at the party. The vice president stopped by to shake a few hands before ducking into the kitchen.

On Tuesday Joan Mondale gave a tea for the woodworkers who lent their furniture pieces to the Vice President's Residence. They included Sam Maloof, Gary Bennett, Wendell Castle and Peter Danko.

It was Castle's birthday and Joan Mondale, with her encyclopedic knowledge of artists, arranged a birthday cake and a chorus of "Happy Birthday."

Last night, after the Mondale party, there was a reception at the Renwick Gallery and a dinner afterward at Decatur House on Lafayette Square for 180 quests, with cermacis as door prizes.

A number of collectors who have lent to the exhibition attended all three events, including Estelle and Martin Shack of Bellman, N.Y. He is an insurance executive, she a student. "We have about 300 pieces of George Ohr's pottery," Shack said. "We've just been collecting it for a few years, but already pots which went for $15 sold in the thousands at the recent Christie's auction in New York."

Natzler told about the collector of his work who saw a pot at an antique dealer's. She asked how much, and the dealer said, "35." Thinking $3500 a fair price for a Natzler bowl, the woman said she'd have to ask her husband. When she came back, she asked the exact price to write the check, and the dealer said, precisely, " $35." When the collector told Natzler about her great bargin, he laughed, looked at the pot and said, "If you'd bought it when I first sold it, it would have cost you $17."