PAINTING, Jock McFadyen tells me, is basically a form of work avoidance. "You know that feeling of not being in school? That's always there,” he tells me as he sips from a pint in the Doric bar in Edinburgh’s Market Street.

"Before I went to art school, I’d feel guilty for being a hippy, getting up late and seeing people going to work. And now I feel pleased about it.”

He recalls with affection the winter nights he’d be painting away “hearing about all the traffic jams on the Hanger Lane Gyratory System. And I'd think: 'Well, I'm not there.'"

The artist lives and works – paints might be the more accurate word – in London, has done since the 1970s. But for the last 30 years McFadyen has also had a flat in Edinburgh and he’s in town today for some business meetings. But he has put aside some time to talk to me.

It’s something he’s good at. He is open and candid about life and work and the ups and downs of both. The wild years, the mistakes made, the choppy sea that is a career in art. The years of money and the years of penury. The going in and out of fashion. Being the new thing and then being usurped by the next new thing. And the investment required in being a painter.

"I'm friends with the poet Hugo Williams. I say to him: 'Hugo, all you need is a pencil and a memo pad. I've got to rent a f****** studio, 2,000 square feet in the most expensive city in the world and find somewhere to live. So, artists are already levered at an early age."

Age certainly is yet to wither him. At 69 he retains an appetite for life. Earlier this year, he tells me, he took one of the 13 motorbikes he owns and rode with his mate, fellow artist Richard Wilson, from Edinburgh to Orkney, riding through the Cairngorms in the freezing cold and then up the tiniest of roads to Scrabster. "Then, fish and chips on the boat."

Like many of his paintings, McFadyen has a bruiser's exterior. All bald head and presence. He projects an alpha male energy (and vocabulary too), but he’s also curious and empathetic. That same duality is on show in his work.

In the 1970s and 1980s, he painted vivid, ugly, pungent, distorted portraits of people, art full of sex and violence, either enacted or implicit. And then in the 1990s people disappeared and he became known for his immaculately rendered paintings of decay; of grubby store fronts and abandoned factories, a contradictory vision of beauty, all rust and water damage.

His work, then, has always been interested in the neglected and the marginalised. There have been times over the last 40 years when he could say as much about himself. But this summer he's been given the accolade of curating the mad excess – some 1,500 works in all – of London's Royal Academy Summer Exhibition. In recent years the job has gone to Grayson Perry, Yinka Shonibare and Michael Craig-Martin, so in a sense it's a reflection of McFadyen's standing that he was asked.

Does this mean you're an establishment figure now, Jock? "I hope so. Well, the Royal Academy is an establishment thing, I think. But artists aren't ever part of the establishment."

"There is this pity that Mick Jagger and Van f****** Morrison have got knighthoods. That's so depressing, isn't it? You've got Sir Richard Long and Sir Antony Gormley and Sir Anish Kapoor. That's establishment. Are they establishment artists?"

This is a typical conversational tic. He will start an answer heading in one direction, quickly tack left or right and then hold up the original question to the light for examination.

Doing the RA show is not "dangerously establishment," he concludes. And the thing about it is, he adds, "it's actually a great show. I have great faith in it. I believe it's one of the most important shows of contemporary art in the world."

What of his own? Over his 40 years as a painter how has McFadyen changed and how has he stayed the same?

"Umm, well, the way of doing it hasn't changed. The preoccupations change, yeah."

He talks about how being commissioned to design the sets for Kenneth MacMillan's last ballet for the Royal Opera House in 1992 marked the shift from painting people to landscape.

"My figures had been getting smaller and Kenneth MacMillan said: 'no figures'. The paintings I did after that changed because I realised, I didn't have to have the figures. It sounds a pretty banal conceptual gear change, but it's quite hard to do if that's your repertory of painting.

"I realised that the empty landscape was psychologically completely different to the figure. You can step into a landscape. But you can't do that with a portrait."

When you're painting a warehouse or a shop front, I ask, what are we to make of it? Are these paintings of desolate places dissections or declarations of love?

"Neither really. Landscape offers itself up to painters because of its textures and colours and all that."

In other words, the attraction of the decrepitude, the weathering, is, he says, first and foremost, painterly.

"It's not really got an intellectual agenda at all. It's a coat hanger for the paint. The paint is the thing."

Given his name and the fact that he spent the first 15 years of his life living in Renfrew and the flat in Edinburgh which he’s owned since the end of the 1980s, and the knowledge that his mum lives up in Carnoustie, the thing I want to know, I tell Jock McFadyen, is how Scottish does he feel?

"Oh God, I don't know. You get to the stage where you wonder about these things."

Buying the flat was an attempt to answer that question, he says. “But I came to the wrong town because I’m from the other side where people are voluble and talkative.”

In fact, he says, he had never visited Edinburgh before he was 28 when he had a film at the film festival. "I came to Edinburgh for the first time when I was 28. I fell in love with Edinburgh as a tourist, effectively.”

McFadyen can’t recall the last time he was in Glasgow. "I don't know anything about the Glasgow art scene at all. I never go there. I've got no relatives there anymore. They all died."

Well, maybe the better question might be, do painters have a nationality? Are you a Scottish painter, Jock? "No, I don't believe in that, really."

That said, the reason he's up in Scotland today is there's a possibility of a few exhibitions here next year. Maybe his homeland is ready to claim him again.

McFadyen started life on a Scottish council estate. His dad was on the factory floor then became a draughtsman in the shipyards and eventually a manager. "That's why we ended up in England. My father's job. I didn't really want to go."

His father could obviously draw and taught McFadyen how to do it, too. But he never encouraged his son’s artistic ambitions.

"In fact, he did say 'you're just a f****** poof.'" McFadyen recalls. "'I'm not actually. I've got three children.' But he thought it was a bit ..."

Unmanly?

"Very unmanly ... Which made it much more attractive."

His father eventually worked for Michelin and when McFadyen was 15, got a transfer to Newcastle-under-Lyme. A few years later he was moved to Dundee. But McFadyen stayed in the Midlands. "I didn't go with them because I'd got my girlfriend pregnant."

It's fair to say that McFadyen's late teens were a little messy. He got expelled from art school with a terrible report, was badly injured in a motorbike crash and suddenly had a new family to support. To do so, he took a variety of manual jobs; as a hospital porter and a binman.

"My lowest point was probably emptying the bins at the art school I used to be a student at. I thought: 'This is it. They're rubbing my nose in it. I used to be at this place, riding up in my motorbike and Cuban-heeled boots.'"

In his early twenties McFadyen got a job in a warehouse. "By that time my little boy Jamie, who's 47 now, was born. I worked in a cash-and-carry, wines and spirits, and it was horrible. Awful. Stacking boxes of Blue Nun. Hated it. 'Oh God, is this it?'

"And the guy I was working with, he liked me. He said: 'You can be a manager and I'll leave this business to you. It's a good business.

“I told him I didn't want to do it. He was so hurt. He said: 'Well, what do you want to do?' And I said: 'I want to go to art school.' He said: ‘It's only the sons of rich people who do that sort of thing, not a guy like you.'"

But McFadyen was committed. He organised an exhibition at a theatre in Stoke. In the foyer.

Still, it was seen, he says, by "the bloke whose job it was to chuck me out of art school. Mr Holt.

“He said: 'I saw your exhibition. I am so proud of you carrying on creating.' He tore up the report and said: 'What do you want me to write?'

Quite a result. "It was also a strange capitulation,” McFadyen says. “Because I was rebelling and then went back cap in hand, because I'd got real. I didn't want to work in a cash-and-carry my whole life."

He got a place at Chelsea art school. He and his wife Carol and son and dog drove down from Stoke in a Hillman Imp van, money from the payoff for the accident in their pocket. The first flat they saw was in Lewisham. The former occupants had just done a moonlight flit. They were clearly junkies. "There were needles all over the floor."

Carol and Jamie went back to Stoke. McFadyen started sofa surfing. Eventually, they all started squatting.

This was the early 1970s and the sixties were still bleeding into the new decade. In Chelsea, McFadyen would see Mick Jagger and Keith Richard. The Mamas and Papas lived across the road and his son played with Christine Keeler's son. It was glamorous but also impenetrable.

"I wasn't part of it. I didn't have any money. You saw this life you couldn't be part of."

Life was complicated. After a year or two in the capital, he and his wife split up. "We got married too young. It was our first relationship. It was a funny time. There was drugs and sex. We started being unfaithful to each other because it was permissible.

"It was my idea,” he adds. “Because it wasn't cool to be married. It was stupid and we were all mixed up."

When they split up, he felt like a failure, he says. But it also galvanised him as a painter.

"I thought: 'I've got to make a fist of this now.’ I was halfway through my course. It hardened me up."

There's a temptation, I suggest, to see all this emotional conflict playing out in the violence of his paintings. Then again, this was also punk's moment. He had his first show in 1978. So, were his paintings a reflection of the time or of his own life?

He ponders this for a moment. "The job of an artist is to make an arresting image,” he says. “It's an advertisement, really."

He points at the pictures on the wall of the Doric. "Look at all those pictures there. Which one is going to jump out and grab you around the throat? If one of them is covered in blood or is a woman's p****, you'd go and look at it.

"That's all there is. Sex and violence."

Of course, he was also still finding his voice. He remembers Jacob Rees-Mogg’s aunt was one of his tutors. She said: 'Oh, Jock' - she was posh but not as posh-sounding as Jacob - your paintings want to deconstruct painting or make fun of painting. But they're still paintings.'

"And she was right. I was in a conundrum about it. A conundrum I gave up later on. I just decided to believe in painting."

He had a good 1980s. Paintings were in, thanks to the success of the likes of Julian Schnabel. There was had a trickle-down effect. He had a one-man show at the Imperial War Museum, exhibited in Berlin and won the ballet commission. He’d also met the musician Susie Honeyman, who was to become his second wife. Things were going well.

"In 1992, I remember, I made £64,000. What's that in today's money? £200,000? It was a good year. I was doing okay.

Then, Susie got pregnant and the recession hit. “In 1993 I earned £8,000 and I had this baby and a mortgage, and I had a flat in Edinburgh and I had to pay the tax on the previous year's income. I had this brand-new car and I couldn't afford to put any petrol in it."

To rub salt in the wounds, the Sensation exhibition in 1997 introduced the new kids on the block. Suddenly, it was all about Damien Hirst and Tracey Emin and the Chapman Brothers. The YBAs had arrived. Being a middle-aged BA, McFadyen discovered, wasn't the thing to be.

"That's difficult. It's like getting dumped by your girlfriend a bit,” he says.

"I didn't sell a big picture until 1995. Susie was doing music lessons. I was teaching one day a week at the Slade. We were really quite poor for about 18 months. I thought it was all finished."

By the turn of the century, though, things began to come back. "Damien had started doing his spot paintings and butterfly paintings. They'd had their kind of punk moment.

"I remember my friend [the art historian] Mary Rose Beaumont once said when Damien started his spot paintings: 'Oh darling, with all that fame he's got to have something to sell. You can't sell dead fish to everyone."

So here he is at 69, still painting, still happy not to have a real job.

"I go to the studio every day. I cycle up there on my bicycle. I'm just painting all the time. I would never not paint. There's nothing else to do."

Even after all these years, for Jock McFadyen, the paint is still the thing.

The Summer Exhibition 2019 continues at the Royal Academy in London until August 12.