The end use design for conventional epoxy formulations is generally aimed at new construction work where the coating will be required to exhibit high build application in few coats, rapid turn and recoat of the substrate, high abrasion, impact resistance and possibly chemical resistance. The end use design for epoxy mastics used in the protective coatings industry is generally aimed at maintenance of older coatings or repair of coatings where they have failed in sections. The longer surface wetting properties of these coatings allows time for the resin to penetrate into and past residual corrosion and older coatings so the requirements for surface preparation can be lessened. While the adhesion of epoxy mastics is superior to residual rust, corrosion product and old coatings, the integrity of the underlying layer cannot be assured and for this reason the highest possible level of surface preparation is recommended for all cases. Author: G. White, Paper 008, 'Corrosion & Prevention 2013'. Reproduced with kind permission from the Australasian Corrosion Association.