A UV curable gel composition adapted to be applied to a nail with a brush to build and extend the nail comprising one or more acrylate/carbamate copolymer resins, one or more urethane methacrylate oligomers of di-functionality, one or more methacrylate resins, one or more Isophorone Diisocyanate end-capped with Hydroxyethyl Methacrylate resins, one or more ethylenically unsaturated mono functional monomers, a photoinitiator and at least one acid-based adhesion promotor wherein the composition having a viscosity of about 11,000 centipoise to about 14,000 centipoise and a specific gravity of less than about 1.2. The invention includes an applicator kit for the composition and methods of its use.