A method of manufacturing a mandrel for use in the internal coating of a pipe elbow or bend comprises the steps of: (i) adjustably positioning a bendable elongate member in a hollow template for the pipe elbow or bend, whereby the elongate member is bent so as to extend generally centrally through the template; and (ii) introducing a flexible material into, and allowing the material to cure in a space between the elongate member and an internal surface of the template.