With his brother, took over the business of Alexander Reid & Sons in 1884. During the horse era, they were blacksmiths and coach builders, repairing all types of vehicles and farm machinery, winning prizes at shows for his machinery and coaches. He even built a sulky with gold-plated fittings. David's sons took over the business when David retired in 1916 aged 68. Edgar changed the name to David Reid and Sons, and began to cater to the motor car trade, selling the blacksmith business to Harry Speer, an employee.