An improved method of coating the welded seam of a metal tube comprising heating the weld area only of the metal tube to a first temperature which is less than the melting temperature of the protective metal coating, applying the protective metal coating over the seam and heating the entire tube preferably with a full body induction coil to a second temperature which is at least equal to the difference between the first temperature and the melting temperature of the metal coating, such that the temperature of the seam area is heated to a temperature equal to or greater than the melting temperature of the metal coating, whereby the metal coating firmly adheres to the welded seam. Where the method of this invention is utilized to apply a protective metal coating over the exterior surface of the welded seam, the protective metal coating is preferably applied by thermally spraying molten metal coating material over the seam and the coating material metallurgically bonds with the seam during the final heating step. In the preferred method, a flux is applied to the exterior surface of the seam prior to applying the coating material. In the method of applying a protective metal coating to the interior surface of the seam, the protective metal coating material is preferably applied by spraying the interior surface with metal coating material in the form of a fine metal powder and liquid flux and the entire tube is heated with the seam located in a lower portion of the tube.