Sinel appears to have left Auckland on the SS Maheno for Sydney, Australia, in January 1914, where he took to a life of subsistence as a sheep shearer, harvest-hand and rabbitter. Soon after the outbreak of the Great War, he left Australia for Britain, from Sydney employed as a trimmer on the SS Rimutaka on 5 January 1915, to Liverpool on 8 March 1915. Walking through England and Scotland, he worked as a designer of printed tin box forms for Hudson Scott & Sons of Carlisle, and as a commercial artist for the highly regarded London commercial artists and advertising agencies, Carlton Studios and Charles F. Higham Limited. Higham's clients included Goodrich Tires, His Master's Voice and the British government. Though six of his brothers had enlisted in the Samoa Expeditionary Force and New Zealand Expeditionary Force, Wilfred Sinel attaining the rank of Lieutenant Colonel, his own attempt to enlist in Kitchener's Army was unsuccessful. Instead, he served part of the war as an able seaman in the British Mercantile Marine.
