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3M

Epoxy Adhesive

DP420 Black • DP420 NS Black • DP420 Off-White • DP420 LH

Handling/Application

Information

Directions for Use

3M™ Scotch-Weld™ Epoxy Adhesive DP420 is supplied in dual syringe plastic duo-

pak cartridges as part of the 3M™ EPX Applicator System. The duo-pak cartridges are

supplied in 50 ml, 200 ml and 400 ml configurations. To use the EPX cartridge system

simply insert the duo-pak cartridge into the EPX applicator. Next, remove the duo-pak

cartridge cap and expel a small amount of adhesive to be sure both sides of the duo-

pak cartridge are flowing evenly and freely. If simultaneous mixing of Part A and Part

B is desired, attach the EPX mixing nozzle to the duo-pak cartridge and begin

dispensing the adhesive.

When mixing Part A and Part B manually the components must be mixed in the

ratio indicated in the typical uncured properties section of this data sheet. Complete

mixing of the two components is required to obtain optimum properties.

Two-part mixing/proportioning/dispensing equipment is available for intermittent or

production line use. These systems are ideal for line uses because of their variable

shot size and flow rate characteristics and are adaptable to most applications.

Apply adhesive to clean, dry surfaces, joint parts and secure until adhesive sets (see

rate of strength build up).

Surface Preparation

The following surface preparations were used for substrates described in this Technical

Data Sheet.

A. Aluminum Etch

Optimized FPL Etch - 3M (test method C-2803)

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 (3M test method C-2802).

2. Optimized FPL Etch Solution (1 liter):

Material

Amount

Distilled Water

700 ml plus balance of liter (see below)

Sodium Dichromate

28 to 67.3 grams

Sulfuric Acid

287.9 to 310.0 grams

Aluminum Chips

1.5 grams/liter of mixed solution

To prepare 1 liter of this solution, dissolve sodium dichromate in 700 ml of

distilled water. Add sulfuric acid and mix well. Add additional distilled water

to fill to 1 liter. Heat mixed solution to 66 to 71°C (150 to 160°F). Dissolve

1.5 grams of 2024 bare aluminum chips per liter of mixed solution. Gentle

agitation will help aluminum dissolve in about 24 hours.

To FPL etch panels, place them in the above solution at 150 to 160°F (66 to

71°C) for 12 to 15 minutes.

Note: Review and follow precautionary information provided by chemical

suppliers prior to preparation of this etch solution.

3.

Rinse immediately in large quantities of clear running tap water.