'3-D Painting' Sprays Metal To Repair Or Rebuild Machines [Video] �GE is showing off a new machine that sprays high-velocity metal powders at broken machines repairing damage in a few minutes without having to weld replacement pieces. The technique which they're calling cold spraying or 3-D painting �(you know like printing) could also be used to make entirely new parts. Got a machine that's deteriorating from wear and tear? Then great maybe you could use this to keep it functioning longer. �Probably not as potentially revolutionary as regular ol' 3-D printing but a neat trick nonetheless.