A system for liquid composite molding includes a first rigid tool part onto which a semi-finished fiber material is positioned, a first vacuum foil arrangeable on the first rigid tool part to provide a first gastight chamber therebetween having a first port, a second vacuum foil and the first vacuum foil providing a second gastight chamber, and granulated material arranged in the second gastight chamber. The semi-finished fiber material is infusible with a matrix material via the first port. A second port is provided at the second gastight chamber for applying a negative pressure thereto. Therein, the granulated material is adapted for forming a second rigid tool part when negative pressure is applied to the second port. I.e. the first vacuum foil, the second vacuum foil and the granulated material function similarly to a vacuum mattress and may be stiffened and collapsed.