The protest, organised by the Campaign Against The Arms Trade, began early yesterday with blockades of entrances to the race course and continued through the day, disrpting traffic in the area.
More than 100 police were deployed and at one point around 30 protesters broke through to block access to the exhibition centre.
Olive Cassirer, a poppy-wearing retired headmistress, was one of many local people there. She had never been to a demonstration before. "This country should not be selling these kinds of armaments," she said.
Kay Lippold, a retired health visitor from Walton-on-Thames, was "ashamed" of the fair. "We used to be proud of what England made and exported," she said. "I don't see how anyone can be proud of this."
Organisers of the Copex 96 exhibition attempted to ward off demonstrators last month. One letter to the campaign warned that its demonstration could divert "precious Metropolitan Police manpower and resources" needed against "impending terrorist attacks".
A spokesman for Sandownsaid that United Race Courses, which owns the ground, was aware of the strength of feeling against the fair. "As far as we're concerned they are just like any other company who applies to have an exhibition here." But the owners were likely to "consider carefully" whether the fair would be held there next year.
The organisers had their own heavy security presence. Some guards were stationed on watch towers, videoing the protest. The guards said only "vetted" members of the press were allowed into the exhibition.
More than 100 companies were listed as exhibitors, including Birmingham Gun Makers, Autauga Arms and the Arab Defence Journal.
Many visitors chose not to discuss their reasons for attending, some shielding their faces. But Lior Caspi, visiting the Israeli delegation, said the protest was based upon a "misunderstanding".
"I think [people would understand better] if they could see that some of these things are legitimate for keeping the peace," he said while videoing the protesters.
The purpose of the fair was revealed last year by a Channel 4 documentary. After it was shown, Copex launched a libel action against the Campaign Against the Arms Trade. The case did not proceed, and the campaign is still trying to recover its costs.Reuse content