He is to meet Ruth Kelly, the Education Secretary, on April 7 and intends talks to be meaningful and constructive.
Unfortunately his charm offensive was only hours old when Hilary Bills, the union's new president, decided to blow a whacking great hole through it.
Ms Kelly was New Labour's worst-ever education secretary, the Sandwell primary head proclaimed to the Press Association, guaranteeing that every newspaper in the land would carry her remarks next day.
It looked as if it was going to go pear-shaped for Mr Sinnott. But, in the event, the most vocal heckling came from outside the conference hall from Newcastle locals, enjoying Bank Holiday cheer. "You get six weeks holiday," they chanted as delegates returned to their hotels along the the Tyne.
Inside the spectacular Sage centre in Gateshead where the 1,100 delegates gathered, it was all sweetness and light (well, almost). The left, whose rabble-rousing normally graces the weekend front pages, were for once not in constant battle with the leadership. The union's robust stand on pensions, its boycott of the workforce agreement and opposition to academies put everyone on the same side. The fact that left-winger Christine Blower - dubbed the "millinery tendency" because of her fine array of headgear on the platform - has been elected deputy general secretary also helped. But the new Sinnott spirit of inclusiveness also meant many potential rows between factions were resolved by executive members beforehand.
Of course there were still numerous strike threats and a few small spats.
Simon Horne accused members who voted to oppose social partnership and modernisation of indulging in empty rhetoric. "You would think we are descending into some kind of sub-Marxist debating chamber," said the Barnet science teacher. "Let's be sensible." That did not prevent Herbert Bukari, from Brent, north London, telling delegates to "kick this Government in the teeth" over pensions.
Mr Sinnott was more subtle in his closing speech, but still gave the Government a going-over. It was "fundamentally mistaken in its romantic fascination with the private sector" and obsessed by parent power and choice, he said.
On a populist note he called for Jamie Oliver to be knighted and more cash for school dinners. But his biggest applause came when he accused the Government of acting like a playground bully by excluding the NUT from talks.
Those on the left of the NUT say the jury is still out on their new leader and that pensions will be his first real test. But there was no denying the "sense of unity" he noted in his speech or the fact that Mr Sinnott had a good first conference.