MIL-DTL-3688D
4.3.3 Sampling for conformance tests. From each inspection lot (see 4.3.1), containers shall be
selected at random, in accordance with ASQC-Z1.4. From each of the containers, 1 quart
samples shall be used in the following tests.
4.4 Test methods.
4.4.1 pH value. Add 10 ml of distilled water to 10 ml of the wax emulsion and determine the
pH with a meter using state of the art electrodes. Check for compliance with 3.3.
4.4.2 Volatile matter. About 100 ml of the wax emulsion shall be distilled and the distillate
tested for specific gravity. Check for compliance with 3.4.
4.4.3 Nonvolatile matter (total solids). Accurately weigh 2 to 3 gm of the sample in a tared
aluminum weighing dish about 8 cm in diameter. Spread the material over the bottom. Heat the
material in an oven at 221° to 230°F (105° to 110°C) for about 4 hours and then cool. Weigh the
dish and contents. Repeat the heating until the last two weightings do not differ by more than 0.5
mg. Usually a second heating of 2 hours will be sufficient. Calculate the percentage of
nonvolatile matter as follows and check for compliance with 3.5.
Percent nonvolatile = B x 100
A
where A = weight (gm) before drying
B = weight (gm) after drying
4.4.4 Wax and resin content. Weigh from 2 to 5 gm of the emulsion into a 250 ml Erlenmeyer
or round-bottom flask. Add several anti-bumping stones or Berl saddles and 75 ml of methyl
amyl ketone (MAK). Attach a Dean-Stark trap and condenser. Reflux on a hot plate or mantle
until the trap is filled with the mixed water and MAK, then continue for an additional hour. Cool
and filter the contents of the flask through paper of medium porosity into a weighed 250 ml
beaker. Wash the filter contents with additional MAK and evaporate the MAK in a hot water
bath with the aid of a current of air, then dry in a 140°F (60°C) oven for several hours. Cool in a
desiccator and weigh. Calculate the percent of wax and resin combined and check for
compliance with 3.6. Retain for softening point test (see 4.4.7).
4.4.5 Ash content. Determine the ash content of the emulsion using a sample of about 10 gm
according to ASTM D5347. Check for compliance with 3.7.
4.4.6 Free alkali. Twenty ml of distilled water shall be added to a 10 ml sample of the wax
emulsion and the mixture boiled, keeping the volume constant by the addition of water, until any
ammonia vapor has been driven off. After all ammonia has been removed as determined by
testing periodically by wet indicator paper held over the sample, the sample shall be cooled, 100
ml of neutral ethyl alcohol (94% or higher) added and the mixture agitated. It shall then be
allowed to settle and the liquid decanted through filter paper. A few drops of phenolphthalein
indicator shall be added. If any pink color appears, the emulsion contains free alkali and fails to
meet the requirements for free alkali in compliance with 3.8.
4.4.7 Softening point. A small amount of the material isolated in paragraph 4.4.4 shall be tested
for softening point by sandwiching between two micro cover glasses and placing on the stage of
5
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business