When he asked for the paintings back or for the cash from their sale, Baikie refused.
Mr Buchanan and Graham Brimble, who had also given the amateur art dealer work to sell, made a complaint to police and in June 2013 Baikie was charged and appeared before the Napier District Court.
At a judge-alone trial last month he denied two charges of theft in a special relationship but Judge Brooke Gibson found him guilty of the offending.
At Auckland District Court this morning, he sentenced Baikie to 150 hours' community work and ordered him to make an emotional harm payment to Mr Buchanan of $5000.
Judge Gibson said the offending involved "a considerable breach of trust" and Crown Prosecutor James Cairney described the defendant as "a conman".
Baikie's lawyer Amber McLean said her client had limited financial means as he was on a sickness benefit and provided medical documents saying he was fit only for "light duties" when it came to community work.
Judge Gibson planned to order repayment of the money at $25 a week but Ms McLean said that would be "crippling" to Baikie.
He adjusted the figure to $20 a week - meaning the full amount would be paid in nearly five years.
During the trial the court heard from several witnesses who had seen him selling paintings around the country.
Barbara Stevens, who knew Mr Buchanan well, told the court via audio-visual link from Perth that she was bewildered to see Baikie passing himself off as the artist at a market in Wanaka eight years ago.
She challenged him about his identity but he brazenly stuck to his story.
There were further sightings in Napier, Karamea and Piha.
Because of the lack of documentation, the Crown could not prove the extent of Baikie's theft but Mr Buchanan said it was at least a couple of dozen.
