In NLRB v. Herman Sausage Co., 275 F.2d 229 (5th Cir. 1960), our circuit held that "generally speaking, the freedom to grant a unilateral wage increase "is limited to cases where there has been a bona fide but unsuccessful attempt to reach an agreement with the union, or where the union bears the guilt for having broken off relations.' NLRB v. Andrew Jergens Co., 9 Cir., 1949, 175 F.2d 130, 136, cert. denied, 338 U.S. 827, 70 S.Ct. 76, 94 L.Ed. 503.