TM 1-1500-204-23-6
(3) Checking. The specific gravity should be checked with a high grade storage battery hydrometer at least
every 4 hours when the cement is used continuously and more often when the 4-hour check shows an excessive change
of composition. When cement is not used continuously, test specific gravity before each use.
WARNING
Dichloromethane (methylene chloride) is toxic when its vapors are inhaled over a period
of time. Adequate ventilation shall be provided for personnel working with this cement,
taking into consideration that dichloromethane (methylene chloride) vapor is heavier
than air. Injury to personnel may occur.
(4) Specific gravity adjustment. When, at time of checking, specific gravity of cement is found to be too low, it
should be adjusted by adding dichloromethane (methylene chloride), MIL-D-6998 to bring its specific gravity to the
maximum end of the specified range. This adjustment requires the addition of dichloromethane (methylene chloride) to
the extent of approximately 2.5 percent by volume of cement per 0.01 unit of required correction of specific gravity. The
cement should be thoroughly stirred and the specific gravity should be rechecked.
CAUTION
Do not mix catalyst directly with promotor or accelerator material since a rapid
decomposition reaction will result.
(5) Mixing. Mix catalyst as soon as opened The cement can be used any time up to 6 hours. Apply only by
brush or spatula.
(6) Alternative. In emergencies when acrylic monomer base cement, MIL-A-8576, is not available,
dichloromethane (methylene chloride) may be used. It is a more active solvent than cement and shorter soak periods
should be used it is also more conducive to blushing or whitening of a joint.
(7) Uses. The type of acrylic plastic being bonded determines the type of adhesive to be used. Acrylic
monomer base adhesive, MIL-A-8576, Type I is used when bonding acrylic plastic, MIL-P-886, and heat resistant acrylic
plastic, MIL-P-5425. Under no circumstances should it be used when bonding material conforming to MIL-P-8184.
WARNING
This material contains a volatile liquid which may prove toxic if vapor is inhaled over
extended periods. Use only with adequate ventilation. When accidentally spilled on
hands or skin, remove immediately by dissolving with ethyl alcohol, Federal
Specifications O-E-760, followed by washing with soap and water. Over-exposure
symptoms are drowsiness, dizziness, and nausea. Treat by wrapping patient in blankets,
provide plenty of fresh air, and obtain medical assistance.
CAUTION
Do not mix catalyst directly with promotor or accelerator material since a rapid
decomposition reaction will result.
c.
Acrylic Monomer and Polymer Base Adhesive. MIL-A-8576. Type II. Non-Solvent. This adhesive is used in
bonding acrylic plastics conforming to MIL-P- 8184. The adhesive cures by evaporation of solvent, but a catalyst,
furnished as a separate ingredient, is required to be added. This adhesive has a clear, thick, syrup-like consistency that
is resistant to oil and water. The shelf life of this adhesive is shown in table 6-3. Acrylic monomer and polymer base
adhesive conforming to MIL-A-8576, Type II is used when bonding craze resistant acrylic plastics conforming to MIL-P-
8184.
d.
Chemigum Coating Cement. Goodyear Chemigum coating cement (Part No. 5071C) is a Buna-N rubber coating
used only for coating on Goodyear nylon pliocel fuel cells. In an emergency, adhesive MIL-A-9117 may be substituted.
6-4