DP-820 Datasheet, PDF (7/8 Pages) 3M Electronics – Acrylic Adhesives

3M^™ Scotch-Weld^™
Acrylic Adhesives
DP805 • DP820
Surface Preparation
For high strength structural bonds, paint, oxide films, 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, environmental aging
resistance desired by the user.
The following cleaning methods are suggested for common surfaces:
Steel:
1. Wipe free of dust with oil-free solvents such as acetone or isopropyl 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
(88°C ± 5°C) 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
(66°C ± 2°C).
Sodium Dichromate
Sulfuric Acid, 66°Be
2024-T3 aluminum (dissolved)
Tap water as needed for balance
4.1 - 4.9 oz./gallon
38.5 o 41.5 oz./gallon
0.2 oz./gallon minimum
3. Rinse: Rinse panels in clear running tap water.
4. Dry: Air dry 15 minutes; forced air dry 10 minutes at 190°F ± 10°F (88°C ± 5°C).
5. If primer is to be used, it should be applied within 4 hours after surface preparation
(or see instruction pertaining to a specific primer).
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 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 the manufacturer’s precautions and directions for use.
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