generally formed of metal or other material such as rigid plastic the member 12 includes a first planar side 14 and a second planar side 16 attached to the second side 16 is a handle 18 which extends parallel to first and second edges 22 and 24 second edge 24 includes a cylinder 26 which has a plurality of evenly spaced uniform grooves 28 each groove will have a width and a depth the width and depth of all the grooves 28 should be the same and constant as can be seen from fig3 generally the distance between grooves is equal to the width of the grooves the grooves 28 in cylinder 26 should extend from below said first side 14 and preferably should extend around and up to or above said second side as shown the grooves 28 in cylinder 26 extend 360 u00b0 which is optimal likewise a cylinder is shown as described later a partially formed cylinder will function for purposes of the present invention any grooved curved surface can be used in place of the grooved cylinder 26 the grooves have a constant depth so that an even amount of mastic or adhesive is applied regardless of the angle of the trowel during application further the grooves.