a small amount of zinc oxide generally 1 to 10 by weight with the lecithin before heating the following examples are illustrative of the present invention and while they cover specific embodiments of the present invention it will be readily apparent to one skilled in the art that these are given by way of explanation not as limitation and that numerous changes in the details may be made without departing from the spirit and scope of the invention as hereinafter claimed comparative exposure tests were conducted by placing 3 inch by 3 inch test panels of automotive steel r 36 q panels in a humidity condensation tester in an inclined position for periods of 40 to 60 days a control panel coated only with unmodified mineral oil ursa p 150 made by texaco developed increased corrosion areas over 50 of the exposed surface area after 14 days over 70 of the exposed surface area after 21 days and 80 of the exposed surface area after 42 days a second control test demonstrates the protective benefits of lecithin without heat darkening in this test lecithin was added to the same mineral oil to form a 5 to 20 by weight lecithin solution this composition was applied to test panels which were then placed in the humidity condensation tester after 42 days corrosion occurred over 10 to 40 of the surface area of the test panels as illustrated below ______________________________________concentration of surface areasalcolec s in corroded aftermineral oil 42 days of exposure______________________________________ 5 40 10 20 20 10 ______________________________________ lecithin alcolec s soybean lecithin as sold by american lecithin company danbury conn was heated for two hours to produce darkening at a temperature of 160 u00b0 centigrade.