7. Preparation of Apparatus
7.1 Chemically clean flasks, glass stoppers, bottles and PFTE screw plugs with solvents to remove oil, then wash the flasks with sulfur-free cleaning powder or liquid. Rinse with tap water, then with distilled water, and dry in an oven.
7.2 Cut a strip of copper 6 by 25 mm (1/4 by 1 in.) (Note 2) and remove blemishes from surfaces with the 240-grit silicon carbide paper. Strips may be stored in sulfur-free acetone at this point for future use. Do the final polishing of the strip by removing it from the acetone, holding it in the fingers protected with ashless filter paper or nitrile gloves, and rubbing with 230-mesh silicon carbide grains picked up from a glass plate with a pad of absorbent cotton moistened with a drop of acetone. Wipe the strip with fresh pads of cotton and subsequently handle only with stainless steel forceps (do not touch with the fingers). Rub in the direction of the long axis of the strip. Clean all metal dust and abrasive from the strip, using successive clean cotton pads until a fresh pad remains unsoiled. Bend the clean strip in a V-shape at approximately a 60° angle and wash successively in acetone, distilled water, and acetone. Dry in an oven for 3 to 5 min at 80 to 100°C and immediately immerse the copper strip in the prepared test specimen of oil (Note 3). Do not use compressed air or an inert gas to dry the copper strip.
NOTE 2 - It has been found convenient to polish a larger piece of copper from which, after the final polishing, several strips of the proper size may be cut.
NOTE 3 - This method of cleaning has been adapted from Test Method D130.
