Magnolia Plastics Adhesives
Magnobond 6388-3 and 6388-5

Providing Custom Formulated Epoxy Systems 1957


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Magnobond 6388-3, Parts A & B and 6388-5, Parts A & B

DESCRIPTION

Magnobond 6388-3 is a two part epoxy adhesive/shim system designed to have good bond strength over a wide range of temperatures (-67°F to 300°F). 6388-3 can be cured at room temperature or accelerated with heat. This system meets the requirements of FMS 1048E.

A more fluid, injection grade version called Magnobond 6388-5 is available. It has all the same outstanding properties as 6388-3.

SPECIAL FEATURES
PROPERTIES
Specific Gravity:   A - 1.4         Shelf Life:  A: > 1 year at < 40°F
                    B - 1.0                      B: 1 year at < 60°F
                  Mix - 1.3 

Viscosity: 6388-3 = Paste           ANSI Classification       A: 4 B: 4
           6388-5 = 350 poise

Mix Ratio:  100 parts by weight A   Flash Point: A: >200°F    B: >200°F
             26 parts by weight B

Pot Life:   53 minutes              Cure Schedule:  1 hour @ 260°F or
                                                    7 days @ 75°F

*Shelf Life Note:  6388-3 has improved room temperature storage life
over other highly reactive adhesives.  Tests have shown that 6388-3
will meet all requirements of FMS 1048E after 1 year at <40°F.        .

Rate of Cure

Rate of cure is judged by development of lap shear strength using
precut test specimens.  Small differences in room temperature will
affect cure rate and pot life.  Results at 75°F are as follows:

          Elapsed time after                   Lap Shear
           mixing, hours                          PSI    
          -------------------                  ---------
                     4                            440
                     5                           1350
                     6                           2150
                     7                           2850
                     8                           2950
                     9                           3000

                 Peak Exotherm and Pot Life, 3 oz. Mass
                 Pot Life:               53 minutes
                 Peak Exotherm °F:      440

                    Lap Shear Strength per FMS 1048E
                    Cure Schedule = 1 hour at 260°F 
                                             
Test Temperature       Strength, PSI         1048E Requirement, PSI
----------------       -------------         ----------------------
     -67°F                3,100                      1,800
      73°F                3,200                      2,200
     180°F                2,800                      2,000
     270°F                2,300                      1,500
     300°F                2,000                        -
     350°F                  900                        -
     400°F                  600                        -

Cure Schedule = 7 days at 75°F

Test Temperature       Strength, PSI         1048E Requirement, PSI
----------------       -------------         ----------------------
      73°F                3,000                       2,500
   **180°F                1,400                         600
   **200°F                1,800                         600

 ** Loaded to 600 psi at 75°F and heated to indicated temperature at
 the rate used by General Dynamics.

Water Resistance, Lap Shear Strength
                        After Water Soak at 75°F      

         Days In Water                       PSI
         -------------                     -------
              0                              3300
             30                              3700
             60                              3700
            120                              3700
            488                              4100
            730                              4500
           2300                              3600

Chemical resistance tests were run per FMS 1048E and MS 277.  Coupons
(not panels) were immersed for seven days.

                                                      Average
                           Test Temperature         Stress, PSI
                           ----------------         -----------
 TT-S-735, Type I                -65°F               2,898
                                  75°F               3,522
                                 180°F               3,053
 TT-S-735, Type II               -65°F               4,123
                                  75°F               4,318
                                 180°F               3,776
 TT-S-735, Type III              -65°F               4,381
                                  75°F               3,994
                                 180°F               3,801
 TT-S-735, Type IV               -65°F               3,510
                                  75°F               3,882
                                 180°F               3,330
 TT-S-735, Type V                -65°F               4,156
                                  75°F               4,252
                                 180°F               4,202
 TT-S-735, Type VI               -65°F               3,591
                                  75°F               4,350
                                 180°F               4,161
 TT-S-735, Type VII              -65°F               4,302
                                  75°F               4,079
                                 180°F               4,045
 Water (30 day immersion)        -65°F               3,422
                                  75°F               3,700
                                 180°F               3,686
 Hydraulic Oil                   -65°F               3,963
                                  75°F               3,630
                                 180°F               3,485
 Jet Fuel                        -65°F               4,351
                                  75°F               3,778
                                 180°F               3,713


   DOUBLE LAP SHEAR STRENGTH, ASTM D-3528 PRIMED ALUMINUM PANELS
          TEST TEMPERATURE                 STRESS, PSI
          ----------------                 -----------
              75°F                            3,300
             350°F                            1,450
             400°F                              900
             440°F                              750

Cure schedule:  7 days at 75°F.  The coupons are heated quickly (3
minutes) to the test temperature to avoid additional cure.

        THERMAL CONDUCTIVITY, ASTM D2214
         cal cm/sec cm2 °C                          4.6 x 10-4

        COMPRESSIVE STRENGTH, ASTM D-695
        Room Temperature Cure                       13,800 psi

        Heat Cure, 1 hour at 260°F                  15,500 psi

        FATIGUE STRENGTH, MMM-A-132

            106 cycles                              1,500 psi
            107 cycles                              1,250 psi

        CREEP RUPTURE, MMM-A-132

                STRESS                    DEFORMATION, INCH
           1600 psi at 75°F                    0.0030
            800 psi at 180°F                   0.0015

                        Fiberglass to Fiberglass
        Corrosive Resistant Epoxy Exposure to 2pH Sulfuric Acid

        Exposure (# days)    6388-5A/6B      101-093     101-094
               0               1760            1720        1800
              264              1720            1740        1780
 Note: All specimens were sandblasted prior to bonding.  The specimens
 were then cured 1 hour @ 200°F.
 


            DANGER                            FIRST-AID
--------------------------------     -------------------------
May cause severe irritation.         Eyes - Immediately flush
Do not get in eyes, on skin          eyes with plenty of water
or clothing.                         for at least 15 minutes.
Do not inhale vapors.                Get medical attention.
Wear rubber gloves & aprons.         Skin - Wash immediately
Use with adequate ventilation.       with soap and water.
Wash thoroughly after handling.      Clothing - Remove clothing
For industrial use only.             and wash before reuse.
Keep container closed.
Do not reuse this container.

Spec Sheet Dated: 02/12/2001


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