Manual laser weld repair is a process where a pulsed Nd:YAG laser is used to melt the surface of a metal, with or without added filler wire, to repair or build-up the surface. The process is totally manual with the operator typically watching the operation through a binocular microscope. The laser on/off can be controlled with a foot pedal. Filler wire can be applied by hand. The part being repaired can be manipulated by hand or using by a joystick to control the table motion below the laser.
One of the earliest uses of manual laser weld repair was to repair surface defects of injection molds. The defect can be ground out. The resulting groove can then be filled-up by applying multiple layers of proper filler wire. This repair would then be ground smooth. The link below shows a video of manual laser weld repair where titanium filler wire is deposited onto titanium plate. An advantage of manual laser repair is low heat input. A shown in the video, the weld puddle freezes and captures the filler wire in between pulses.
These images show a groove ground onto the surface of titanium and then repaired using manual laser weld repair similar to the video along with a typical metallographic cross section of a multi-layer deposit.