The maximum thickness in any one application shall not exceed that recommended by the paint manufacturer.Wet film thickness gauges shall be used to make frequent checks on the applied wet film.The Works Contractor shall maintain at the site of painting operations, a dry film thickness (DFT) tester of an approved type with a valid current calibration.Build-up of each material to required thickness shall be made prior to the application of the subsequent coat; final film build shall be at least the minimum specified.