. Sean put 60 flyers through the doors with the simplest but most effective marketing strategy - "Work Wanted". Around 45 people took him up on the offer and he was in business - fixing things, painting and decorating and gardening. He even painted shed doors for the rector, Steve Dempsey.
Mr Dempsey's regime at Brechin High can't claim all the credit for turning out this natural entrepreneur with the admirable work ethic. But the Construction Crafts course Sean did last year appears to have pointed him in the right direction.
Along with 16 other S3 pupils, Sean spent one afternoon a week "going to work" on a unique placement at Forster Roofing in Brechin. The pupils used staff canteen and training facilities for three months, while learning roofing skills from Angus College lecturers who came trained them on indoor model rigs.
The course and experience has been inspirational for Sean, who used what he learned on the Skills for Work Intermediate 1 Construction course to set up in business himself. "I took the flyers when I was doing my paper round. They said "Work Wanted" and I advertised the things that I was doing in Construction - painting and decorating, brick work, that kind of thing. It was anything they didn't want to do or couldn't do," Sean explains.
That was earlier this summer and the work is still coming in, though Sean can only tackle the jobs at weekends, now he's in fourth year.
He's coy about how much he's trousered over the summer when all his pals were playing computer games and bleeding their parents dry. "A mini- millionaire," he jokes.
Mr Dempsey is proud of his pupil's initiative, delighted the school has won an award for its business partnership with Forster Roofing and Angus College, and extremely pleased he got his sheds painted. "I wrote him a reference so, if he was going to do a job, he could show people," says the head.
Angus Council made The Partnership Excellence Award to Brechin High for its collaboration with Forster Roofing and Angus College. The school has about 10 similar partnerships in the community. "The Construction Crafts class is doing one of the Skills for Work courses, an SQA Intermediate 1 course which is becoming more and more popular in Scotland, with a fair number of schools offering it, usually done through the college where the college could do the delivery," says Mr Dempsey.
"The difference with this particular development was that the kids went to Forster Roofing. Instead of doing it at the college or doing it at the school, they actually did the delivery in the workplace in the training room," says the rector.
"We won an award because of the quality and impact of the partnership agreement we've got with Forster and Angus Council. It was recognised as something quite innovative, because of the risk associated from Forster's point of view, taking kids into their workplace."
The company's links with the school are vital to help them recruit staff for a range of posts, as the company's human resources manager, Maureen Douglas, explains. "There's been a dearth of professional and trades skills in construction, so we've worked closely with the school for a number of years and if we ever had a vacancy, we advertised it there first."
As we're shown around Forster's headquarters and the model roof rigs like the tops of Wendy houses, Sean describes what it was like to join the workforce.
"It was great, it was easy - you came in, got your stuff on and you felt good. You got on the rigs and started battering away with the hammers and working together as a team. It was fun," he says. "I would consider it as a job - it's a good thing to know."
Colin Johnson, curriculum manager for construction at Angus College, said the pupils' experience of a real-life working environment had been critical to the venture's success. "It was the whole experience of being in an employer's premises, rather than being at school or college," he said.
Sean's friend Shaun Stewart, 14, agrees: "It was a good experience. It felt real, if you know what I mean. Just a really good experience." (At this point we become distracted by a discussion of Shaun's eyebrow piercings, which look like diamonds and apparently glow in the dark.)
Back next door in the staff cafeteria, the boys get a chance to catch up with company chairman John Forster, who launched the firm in 1990 and is committed to this relationship with the school. He is delighted to hear how Sean Cannon spent his summer.
"I can relate to that, because probably my first business venture started back at the age of 13, when I used to buy Mars Bars from the local shop and then sell them at breaktimes at school. I used to buy them for about 12p and sell them for 20p and made a very good profit," says Mr Forster, whose business now operates all over Scotland and employs more than 120 people.
For Sean and his pals, the second year of their Intermediate 1 course is getting under way. "They are doing plumbing, which I think they are quite looking forward to," says Mr Johnson.
The allure of blocked drains is simple: "Because it's good money. When you get your plumber's licence and get Corgi-registered, you can go anywhere," says Sean, already planning his updated CV for next summer.