He was educated at the Christian Brothers' College in Gympie and after leaving school was a tea merchant in 1932, a traveler for the Castlemaine Perkins and from 1947 until 1975 a men's Mercer at Beaudesert.
On 24 April 1934 he married Muriel Eileen Burke (died 1978) and together had two sons.
Later changing his middle name to Gabriel, Barnes died at Southport in June 1983 and was buried in the Southport Lawn Cemetery.