Structural Core Splice Adhesives

AF 3028 • AF 3028 FR

- 3 -

Product Performance

(continued)

6. Tube Shear Strength:

The tube shear strength has been determined on AF 3028 and AF 3028 FR using

the procedure outlined in AdhD Test Method C-280. Tube shear specimens are

prepared by placing 45 ± 0.2 grams of adhesive between the walls of two 9" long

tubes and curing in an oven. After cure, the tubes were cut into 0.5" specimens as

shown below and tested by pushing out the inside tube at a rate of 0.05"/minute.

5. Splice Delamination Strength:

Splice delamination has been determined in accordance with the procedure

outlined in MIL-C-7438F, Paragraph 4.7.9.

Honeycomb Core Used: 5052 alloy-1/4" cell-4.0 mil foil – 1/2" thick non-perf.

Size: 5" x 10" (core ribbon perpendicular to ten inch dimension).

Splice Position: Centered and perpendicular to the 10" dimension running the full width of

the specimen.

Number of Layers: One layer of adhesive.

Cure: 1 hour at 250°F (121°C).

Load Rate: 0.25" per minute.

Test Temperature

AF 3028

AF 3028 FR

75°F (24°C)

110 lbs (490 N)

100 lbs (445 N)

Core Splice Adhesive

Outer Tube – 1" OD, 0.049" thick

5052-0 bare aluminum

Innter Tube – 1/2" OD, 0.049" thick

5052-0 bare aluminum

Test Specimen

Tube Shear =

P (lbs)

P = Force required to push out inner tube.

Cure Cycle A: 250°F (121°C) for 90 minutes, 4-6°F rise rate/minute.

Cure Cycle B: 350°F (176°C) for 60 minutes, 7.5°F rise rate/minute.

Test Results (Typical Averages)

Cure Cycle A

Cure Cycle A

Cure Cycle B

Test Temperature

AF 3028

AF 3028FR

AF 3028

°F

(°C)

psi

(MPa)

psi

(MPa)

psi

(MPa)

-67

(-55)

1100

(7.6)

—

—

—

—

75

(24)

950

(6.5)

1070

(7.4)

1036

(7.1)

180

(82)

950

(6.5)

—

—

—

—

250

(121)

900

(6.2)

—

—

—

—

350

(176)

492

(3.4)

—

—

565

(0.4)