Kelynack arrived in Sydney in 1854, with fellow Cornishman and minister William Curnow, and he served in the Bathurst circuit until 1856, whence he transferred to Braidwood and then to Yass in 1860.
After appointments to Chippendale, Parramatta and Wollongong he served in York Street, Sydney (1865–67) and Surry Hills (1868–70).
During the 1860s, Kelynack was a councillor of Newington College, a committee member of Sydney City Mission, and became coeditor of the Christian Advocate and Wesleyan Record with William Curnow.
He returned to Australia via the United States of America where he addressed the students at Drew Theological Seminary and preached in New York City, Baltimore and Chicago.
On his return to Sydney in 1878, Kelynack was appointed to the Bourke Street Church and two years later was elected president of the New South Wales and Queensland Annual Conference.