3M™ Scotch-Weld™ Epoxy Adhesive 2158 B/A

Handling/Application Information (continued)

Surface Preparation

For high strength structural bonds, paint, oxide lms, oils, dust, mold release agents and all other surface

contaminants must be completely removed. The amount of surface preparation depends on the required bond

strength and the environmental aging resistance desired by user.

The following cleaning methods are suggested for these common surfaces:

Steel:

1. Wipe free of dust with oil-free solvent such as acetone, isopropyl or alcohol solvents.*

2. Sandblast or abrade using clean ne grit abrasives.

3. Wipe again with solvent to remove loose particles.

4. If a primer is used, it should be applied within 4 hours after surface preparation.

Aluminum:

1. Vapor Degrease: Perchloroethylene condensing vapors for 5-10 minutes.*

2. Alkaline Degrease: Oakite 164 solution (9-11 oz./gallon water) at 190°F ± 10°F (88°C ± 5°C) for 10-20 minutes.

Rinse immediately in large quantities of cold running water.

3. Acid Etch: Place panels in the following solution for 10 minutes at 150°F ± 5°F (66°C ± 2°C).

Sodium Dichromate 4.1-4.9 oz./gallon

Sulfuric Acid, 66°Be 38.5-41.5 oz./gallon

2024-T3 aluminum (dissolved) 0.2 oz./gallon minimum

Tap Water as needed to balance

Note: Read and follow component supplier’s environmental health and safety recommendations prior to preparation

of this etch solution.

4. Rinse: Rinse panels in clear running tap water.

5. Dry: Air dry 15 minutes; force dry 10 minutes at 150°F ± 10°F (66°C ± 5°C).

6. If primer is to be used, it should be applied within 4 hours after surface preparation.

Plastics/Rubbers:

1. Wipe with isopropyl alcohol.*

2. Abrade using ne grit abrasives.

3. Wipe with isopropyl alcohol.*

Glass:

1. Solvent wipe surface using acetone or methyl ethyl ketone (MEK).*

2. Apply a thin coating (0.0001 in. or less) or primer such as 3M™ Scotch-Weld™ Structural Adhesive Primer EC-

3901 to the glass surfaces to be bonded and allow the primer to dry before bonding.

*Note: When using solvents, extinguish all ignition sources, including pilot lights, and follow manufacturer’s

precautions and directions for use.

Storage and Shelf Life

Store product at 60-80°F (15-27°C) for maximum storage life.

3M™ Scotch-Weld™ Epoxy Adhesive 2158 B/A has a storage life of 24 months from date of manufacture in

unopened containers. Rotate stock on a “ rst in- rst out” basis.