A device (100) for manufacturing ready-to-use knifing filler for spackling surfaces, in particular of motor vehicle bodies, by mixing a binder component and a hardener component to a pasty or fluid mixing material using a mixing device (1) consisting of a hollow cylindrical stator section and a rotor section rotatably accommodated, and an annular gap forming the mixing chamber formed between the rotor section and stator section. The device has a fixed base (101) with a supporting plate (104′) that forms a filler head (104) for holding a supply tank (90) for the binder component and for three supply tanks (91, 92, 92′) for the hardener component, and a first drive unit (102) to actuate the hydraulic cylinder for the supply tank (90) for the binder component and for two supply tanks (91, 92) for the hardener component, a second drive unit (250) for the mixing device (1) and a third drive unit (270) to actuate the plunger rod designed as a toothed rack, wherein all three drive units are combined in a control device (280), which is used to control a first running of hardener component for 1 second and a last running for 1 second, as well as the supply of binder component and other hardener components in the mixing device (1).