while the solution is coolinq,prepare a buchner funnel for vacuum filtration.(Fiq 16) select a piece of filter paper that fits into the funnel properly,and wet the paper to seat it. attach the filter flask to the aspirator. turn on the water for the aspirator qently. the moist paper should be flat and wrinkle-free in the bottom of the funnel.ask your instructor to check your apparatus before you begin the filtration.