method of example 1 of u s pat no 5 637 663 it is 43 mole hfp and 57 mole tfe polymer b is used as a 5 solution in fc 40 this example shows how a length of nylon string is coated in a small scale batch process a length of nylon string sufficient for the complete stringing for one tennis racquet is coiled to a 5 inch 127 mm diameter this coil is totally immersed in a 3 wt acetone solution of polymer a to achieve complete wetting of the surface of the string by the solution upon removal excess solution is allowed to flow back into the container of polymer a the wet string is placed in an air oven at 80 u00b0 c 176 u00b0 f for five to ten minutes the polymer coated string is removed and cooled to room temperature a sample of the string is cut to provide a cross section which is subjected to sem to determine coating thickness measurements at magnifications of 20 000 to 30 000 times show the thickness of the first coating to be 0 1 u03bcm then the coiled and coated string is totally immersed in a 5 wt fc 40 solution of polymer b to achieve complete wetting a similar drying step at 80 u00b0 c 176 u00b0 f is conducted after removal from the oven and cooling to room temperature the coated string is ready to be placed into a tennis racquet a sample of the string is cut to provide a cross section which is subjected to sem to determine coating thickness measurements at magnifications of 20 000 to 30 000 times show the thickness of the first coating plus the second coating to be 0.