Abstract: The present invention generally relates to a turbine coating apparatus and a spray gun assembly therefor. More specifically, the present invention relates to a spray gun assembly comprising a gun support mountable to the turbine coating apparatus and at least one spray gun mounted to the gun support. The spray gun is adapted for providing a spray of a coating substance onto a cluster of solid forms to be coated in the apparatus, where the spray defines a spray angle of less than 90 degrees relative to the coating plane defined by the cluster of solid forms in movement.