Castor oil (C) was reacted with commercial epoxy resin (E) (diglycidylether of bisphenol-A, DGEBA) at various mole ratios. The resultant products were designated as CEs. Unsaturated polyester resins were prepared by reacting DGEBA with maleated / tetrahydrophthalated cyclohexanone formaldehyde resins based on cyclohexanone formaldehyde (CHF) resins and designated as (Ma,bUPE and Pa,b UPE) respectively. A commercial alkyd resin was blended with various proportions of CEs and Ma,bUPE and Pa,bUPE. A unique solvent system, which shows a one - phase clear solution and a clear coat of binder system, was used. All the blends were applied on mild steel panels and characterized for drying time, adhesion, flexibility, hardness, impact resistance and chemical resistance properties.