A water borne binder composition comprising (a) an aqueous dispersion of an acrylic copolymer comprising carboxylic acid and ethylene-urea functionality, having a weight average molecular weight below 200,000 and a Tg<−15° C., as calculated from the monomer composition using the Fox equation; and (b) a water soluble complex of a transition metal, preferably zinc. A coating composition comprising the water borne binder and a wood substrate coated with the coating composition