For a cement wash to go over old cement stucco, place a few handfuls of cement in a bucket, and add water until the cement is of the consistency of thin cream. The wash should be mixed in small quantities as required, and should be kept constantly stirred while being used. The old work must be well cleaned down, and rubbed with a stiff wire or bristle brush to remove all dust. If the cleaning down is properly done, the cement wash should adhere without rubbing off. Try first 1 sq. yd. of surface, and wait until it is dry. If the wash rubs off, a little size may be mixed with it; but this admixture of size is not to be recommended, and should be avoided if possible.