3M DP270

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 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 (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: 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 (66°C ± 5°C).

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

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 60 minutes before bonding.

Application

For maximum bond strength apply product evenly to both surfaces to be joined.

Application to the substrates should be made within 70 minutes. Larger quantities and/or higher temperatures will reduce this working time.

Mixing

For Duo-Pak Cartridges: If mixing of Part A and Part B is desired, attach the EPX applicator mixing nozzle to the duo-pak cartridge and begin dispensing the adhesive. For hand mixing, expel the desired amount of material and mix thoroughly to obtain a uniform color.

EPX Applicator systems.

Mix thoroughly by weight or volume in the proportions specified in the typical uncured properties section to obtain a uniform color.

For Bulk Containers: Mix thoroughly by weight or volume in the proportions specified in the typical uncured properties section to obtain a uniform color.

Curing

Join the adhesive coated surfaces and allow to cure at 60°F (16°C) or above until firm. Heat up to 200°F (93°C) will speed curing.

Keep parts from moving during cure. Contact pressure necessary. Maximum shear strength is obtained with a 3-5 mil bond line.

Clean-Up

Excess uncured adhesive can be cleaned up with ketone type solvents.