An aqueous composition comprising: (a) an aromatic-acrylic polymer comprising from 3 to 11 wt % polymerized units of C3-C6 carboxylic acid monomers and from 0.2 to 3 wt % polymerized units of anti-agglomerating monomers; (b) a reactive polyfunctional thermosetting resin; (c) a polyvalent metal ion; and (d) a polyfunctional curing agent, wherein the curing agent is stored separately from the thermosetting resin.