Abstract: An in situ generation of a biocide, such as monochlorodimethylhydantoin (“MCDMH”) and/or dichlorodimethylhydantoin (“DCDMH”), suitable as a preservative for paints is provided along with a dried surface coating having a biocidal surface comprising MCDMH and/or DCDMH. Also, the present invention provides for a dried coating have a surface comprising an inert compound, such as dimethylhydantoin (“DMH”), whose biocidal capabilities may be activated by applying a chlorine treatment to the dried surface. Further, this invention provides for liquids that can be used to create the above-described coatings.