Comparative tests were made of protective coatings developed in the Tatar Scientific Research and Design Institute for the Petroleum Industry, the State Scientific-Research Institute for Glass, and Ural Polytechnic Institute in 3% sodium chloride solution by the infrared reflection spectroscopy method. The results are compared with data on water resistance and visual evaluation of failure. Erosion from the surface layers of the alkaline borate constituent is shown. This process occurs more actively in less water resistant enamels.