Epoxy Adhesive EC-3333 B/A

Technical Datasheet

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Product Application

Note: While this information is provided as a general application guideline based upon

typical conditions, it is recognized that no two applications are identical due to, among

other things, differing assemblies, methods of heat and pressure application production

equipment and other limitations. It is therefore suggested that experiments be run,

within the actual constraints imposed to determine optimum conditions for your

specific application and to determine suitability of product for particular intended use.

I. Surface Preparation

A thoroughly cleaned, dry, grease-free surface is essential for maximum

performance. Cleaning methods which will produce a break free water film on

metal surfaces are generally satisfactory.

A. Aluminum: Optimized FPL Etch – 3M Test Method C-2803 or ASTM D2651

Method 8.

oz./gallon of water at 190° ± 10°F for 15 ± 5 minutes. Rinse immediately

in large quantities of cold running distilled, deionized, or tap water

(3M Test Method C-2802).

2. Acid Etch – Immerse panels in the following solution for 10 minutes at

150° ± 5°F:

4.1 - 4.9 oz./gallon

Sulfuric Acid 66° Be

38.5 - 41.5 oz./gallon

2024-T3 aluminum (dissolved)

0.2 oz./gal. minimum

Tap Water as needed to balance

3. Rinse immediately in large quantities of clear running tap water.

4. Air dry approximately 15 minutes followed by a force dry at 150° ± 10°F

for 10 minutes.

5. Current theory suggests that both surface structure and chemistry play a

significant role in determining the strength and performance of bonded

structure. It is therefore advisable to bond or prime freshly cleaned surfaces

as early as possible after preparing to avoid contamination and/or

mechanical damage.

B. Fiber Reinforced Epoxy Laminate Surface and Plastic Surfaces

1. Abrade surfaces to be bonded with 180 grit sandpaper or a 3M™ Scotch-

Brite™ pad (do not cut through resin into reinforcing fibers).

2. Wipe with unsized cheese cloth soaked with Ketone type solvent such as

Methyl Ethyl Ketone (MEK).*

*When using solvents, extinguish all ignition sources in the area, observe

precautionary measures as well as all appropriate government and

industry regulations.

3. Thoroughly dry before application of adhesive.

C. Primer Application

Although 3M™ Scotch-Weld™ Epoxy Adhesive EC-3333 B/A gives

excellent performance on unprimed surfaces, the use of corrosion inhibiting

primers such as 3M™ Scotch-Weld™ Structural Adhesive Primer EC-3960

or EC-3924B are suggested for maximum long-term durability and

environmental resistance. See technical data sheets for application

instructions. In the Typical Product Performance section, the Scotch-Weld

EC-3960 Primer was cured for one hour at 250°F prior to bonding.