Molenaar was asked by publisher Rob van Bavel to take over the popular Dutch comic series 'Storm', following the death of the original artist Don Lawrence in 2003. Molenaar gave up his dayjob at the reproduction department of a technical office and has done the artwork for new stories in cooperation with colorist Jorg De Vos since 2006. The stories, written by Martin Lodewijk and later by De Vos, are first published in Eppo magazine and then in albums by Van Bavel's Don Lawrence Collection. In 2013, Molenaar also started a spin-off series starring the female character 'Roodhaar', for which the scripts are provided by none other than 'Conan the Barbarian' writer Roy Thomas.
In 2014, his talents were also recognized by Standaard in Belgium, who hired him to draw 'J. Rom - Force of Gold', the second more adult spin-off of their 'Suske en Wiske' franchise. In 2016, he was one of the six Dutch artists to draw a comic book starring Willy Vandersteen's 'Suske en Wiske' for S.O.S. Children's Villages, based on a story by a Dutch celebrity. Molenaar made the story 'De irritante imitator' with TV personality Carlo Boszhard.
Since 2016, he is part of "The Wolfpack", a creative team of Standaard Uitgeverij assigned to come up with new ideas for spin-offs.