Born in Penzance, the son of Cornish boxer Tommy Barrett, he was himself an amateur boxer for a period before taking up sculpture in 1972. His occupations as a steeplejack and steel erector influenced him strongly in relation to structures, and he believed in the spirit of the materials with which he worked. He worked not only in wood and stone but also in steel and other metals; he usually worked stone in winter and wood in summer.

Something of a gypsy character, and from living many years in caravans and makeshift structures, he was independent of most other artists, and joined no organisations or committees related to the bureaucratic systems of art.  Living in a caravan in the woods near Hayle he was unpredictable in his responses, but also deeply spiritual about the work he produced. His friend, Roger White, took his career in hand in later years and sold sculptures for him from his decorative arts and oriental carpet emporium in Chapel Street, Penzance.  In 1982 Max was commissioned to construct Gentle Wave at Land's End; and large works by him, both in stone and steel, are located at Truro (Sainsbury's Supermarket) and at Hayle: he presented a sculpture to the town, a lithe figure of a young girl holding a fish aloft, and this has been installed on the harbour front.

When he knew he was terminally ill he held a large one man exhibition and sale of his work at the Acorn Theatre, Penzance in 1996, and in the town's Royal Geological Museum, accepting any reasonable offers from the public.