A solvent free (aqueous) system was tested in anticipation of solvent-free environmental standards. The goal of this project is to test the adhesion strength of various topcoats to plastics such as thermoplastic olefin (TPO) and polypropylene (PP), both with and without a waterborne adhesion promoters (CPO) using a quantitative tensile test. A strip of cloth is painted with the topcoat and then left to dry on a piece of plastic. The cloth is then pulled from the plastic using a Instron and the required force is plotted on a chart recorder. The force required for samples with the CPO is compared to the force required for samples with no CPO. Polypropylene and thermoplastic olefin experience substantial increases in topcoat adhesion, twelve-fold and twenty-three fold, respectively, when given a surface treatment with a waterborne chlorinated polyolefin (CPO). A good portion of this strength increase, 40 - 60%, was retained following a twenty four hour submergence in 22°C water. This strength retention suggests the possibility of exterior applications for waterborne CPO's as adhesion promoters.