The whole of his long missionary life Fr Wim worked in Sarawak, both in remote and up-river missions as well as in town. He immersed himself in the Iban culture and language. The list of places where he served starts in Kanowit where he arrived in the year of his ordination. A year later he was appointed to Song, and four years later, in 1962, to Binatang, where he stayed for two years. He then returned to work in Song for six years. In 1970 he was appointed to Julau.
Three years later he went back to Kanowit where he worked until 1988. In that year he was appointed to the town of Sibu, where he worked for eleven years. He included in his work looking after the longhouses in the Igan and Oya region. In 1999 he was transferred to the up-river mission of Julau, where he served for three years, after which he returned to Sibu. This was to be the place where he continued to serve until his retirement to ‘Missiehuis Vrijland’, in Oosterbeek, The Netherlands, in August 2011.