this invention provides methods for preparing mixtures of styrene and maleic anhydride co - monomer , applying that mixture to the surface of a solid porous substance like wood , allowing the mixture to penetrate the surface zone of the material such as wood and causing it to quickly cure in the surface zone of the material . the keys are the low viscosity of the mixture that causes it to penetrate quickly and well , and its reactivity that causes it to cure before it either evaporates or becomes too dispersed within the material . the polymer reinforcement and hardening is therefore effectively restricted to the surface zone or shell . this produces a reinforced , hardened , protective shell around the porous material .