Will we ever think of wobble boards the same way again after a London court found Rolf Harris guilty of 12 charges of indecent assault on Monday? What will the Queen do with her 80th birthday portrait, now tainted by association with the entertainer? According to public relations experts, the tunes of Jake the Peg and Tie Me Kangaroo Down, Sport will forever make us cringe instead of smile.

Sue Cato, head of PR firm Cato Counsel and an expert in crisis management, says the betrayal of trust is so great because of the persona Harris portrayed to the public. “He was everyone’s best mate, a joker. He built a character you can trust and rely on.”

Harris will be sentenced on Friday and has been told to expect a custodial sentence, with each charge carrying a maximum of two years’ jail time. Cato says 84-year-old Harris won’t have the chance to redeem his public image. He has also continuously denied any wrongdoing, which will make any apology more difficult. “It’s a different kind of betrayal. Where it’s political or alcohol-related where you can say sorry — this is a different class.”

Toby Ralph, PR strategist told Crikey: “Can anyone look at one of Hitler’s watercolours without thinking of the atrocities he was responsible for? The greatest hits of Rolf Harris will simply be an aide-memoire to his predatory sex crimes. He’s tied his last kangaroo down and hung up his wobble board for all eternity.”

Throughout the trial the Australian entertainer enlisted the public relations services of Bell Pottinger , a huge international PR firm that Cato describes as “one of the best”.

Harris was in his prime in the 1950s and 1960s, but Cato says the age of his fans won’t make a difference to how they perceive him and his crimes. “I think that it doesn’t matter if someone is 90, 80, 70, 40 or 20, it’s the thought that young people are put in that kind of danger that matters.”

Ralph agrees: “Rolf will be abandoned by his older fans. Nobody wants to be reminded of the indecencies lurking under his artificial avuncularity. Nobody wants to be associated with it.”

Lauren Rosewarne argued this week on The Drum art should not be tarnished by the artist’s misdeeds, but it seems unlikely that we will ever view Harris’ body of work the same way again.

Cato points towards the image of Jake the Peg, with Harris in his overcoat and third prop leg as having a particularly dark aspect in hindsight. “What we’ll think about when we think about his music and art will be uncomfortable and dark memories.”

Art is being stripped from the walls of Edith Cowan University in Harris’ home state of Western Australia, and his honourary titles are also being removed. It unknown what will happen to Harris’ portrait of Queen Elizabeth, as the portrait’s whereabouts are unclear.

Many of the pop culture favourites of Harris’ era are now tainted with convictions of child sex abuse, from Jimmy Savile’s Jim’ll Fix it to Robert Hughes’ appearance in Hey Dad!.

According to Ralph, these crimes will never be forgotten by the public. “Some crimes are excusable by the public. For example, Jordan Belfort, the Wolf of Wall Street, has made a roadshow out of his exploits. Even O.J. Simpson, who many still assume was guilty, is an A-lister at Hollywood parties. But sexual assault on underage girls is at far end of the taboo scale; Harris will not be forgiven.”

The viewing public has a strange relationship with celebrities and artists who are convicted or accused criminals, with the likes of Roman Polanski continuing to make films from abroad after being found guilty of child sex charges in 1977. Although Woody Allen has been cleared of sexual abuse allegations against his daughter Dylan Farrow, a spectre of unease still hangs around his work. The allegations resurfaced this year, coinciding with the release of Blue Jasmine, yet viewers and awards still came. Director Lars von Trier was banned from the Cannes Film Festival in 2011 after joking that he sympathised with Nazis, but his film Nymphomaniac continued to draw audiences this year.

But some stars are unable to redeem their reputations. Mel Gibson’s career has never recovered from an anti-Semitic rant at a police officer in 2006, as well as homophobic and racist outbursts and accusations of domestic violence.

As Cato says, “redemption will be impossible on this one”.