3M

Epoxy Adhesives

DP125 Translucent and Gray

- 6 -

Surface Preparation

For high strength structural bonds, paint, oxide films, oils, dust, mold release agents

and all other surface contaminants must be completely removed. However, the

amount of surface preparation directly depends on the required bond strength and the

environmental aging resistance desired by user.

The following cleaning methods are suggested for 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 fine 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. Alkaline Degrease: Oakite 164 solution (9-11 oz./gallon water) at 190°F ± 10°F

for 10-20 minutes. Rinse immediately in large quantities of cold running water.

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

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

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

4. Dry: Air dry 15 minutes; force dry 10 minutes at 150°F ± 10°F.

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

Note: Read and follow supplier’s environmental, health, and safety documentation for

these chemicals prior to preparation of this solution.

Plastics/Rubber:

1. Wipe with isopropyl alcohol.*

2. Abrade using fine grit abrasives.

3. Wipe with isopropyl alcohol.*

Glass:

1. Solvent wipe surface using acetone or MEK.*

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

Metal Primer EC3901 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.

Application Equipment

Suggestions

For small or intermittent applications the 3M™ EPX Applicator System is a

convenient method of application.

For larger applications these products may be applied by use of flow equipment.

Two part meter/mixing/proportioning/dispensing equipment is available for

intermittent or production line use. These systems may be desirable because of their

variable shot size and flow rate characteristics and are adaptable to many applications.