He studied at the vocational school in Basel from 1923 to 1927, where his graphics teacher was the painter Fritz Baumann, the founder of the Expressionist art group Das neue Leben (The new life).

Accordingly, Wiemken's illustrations from this time show a clear Expressionist influence, and he associated with the Gruppe Rot-Blau [de], which had been founded by students of Ernst Ludwig Kirchner.

In 1927, he spent the summer semester at the State University of Applied Arts in Munich, where he was taught by Fritz Helmuth Ehmcke and Richard Klein.

In 1928 and 1929, he travelled to the artists' colony of Collioure in Roussillon and to Ticino with lifelong friends Abt and Walter Bodmer [de].

In 1936 he took part in the exhibition "Zeitprobleme in der Schweizer Malerei und Plastik" ("Time-dependent problems in Swiss painting and sculpture") at the Kunsthaus Zürich.