Unsaturated polyester-based repair resins, such as Bondo™, are widely used for automotive repair, marine repair, sporting equipment repair, and household repair of metal, composites, plastics, and wood. Commercial repair resins usually contain 10-40 wt% styrene, which is a hazardous air pollutant (HAP). The reduction of HAP usage in the Army has become a high materials need in the Army because of EPA regulations, including the Defense Land Systems for Miscellaneous Equipment (DLSME) National Emissions Standard for Hazardous Air Pollutants (NESHAP) and the Reinforced Plastic Composites NESHAP. Fortunately, non-volatile fatty acid monomers can be used to replace the styrene in these repair resins. Fatty acid monomers were formulated with vinyl ester or unsaturated polyester monomers to match the glass transition temperature of commercial repair resins. Various inorganic fillers were incorporated to match the rheological and mechanical properties of commercial repair resins. Besides having no HAP content, and therefore exceeding emissions regulations, these fatty acid-based repair resins reduce toxicity effects on workers, reduce the smell, increase resin shelf-life, and improve the paint-ability of the repaired area.