His initial works were connected to painting, but his interest in representing volume led him towards sculpture.

[3] Between 1964 and 1968, he served as the Executive Secretary of the Museum of Contemporary Art at the University of Chile, later assuming the role of Director.

[2] In his early pieces, Assler created cut-out templates on particleboard, which, when repeated with gradual enlargements and glued together, formed volumes with a stepped texture and various shapes.

However, his desire for sculptures to relate to humans and nature in outdoor settings led him to use concrete in his works.

To achieve this, he creates molds from expanded polystyrene, commonly referred to as "plumavit" or "aislapol" in Chile, into which he later pours the concrete mixture.