Structural Adhesive Film AF 191

Technical Datasheet

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Surface Preparation

A thoroughly cleaned, dry, grease-free surface is essential for maximum performance.

Cleaning methods which will produce a breakfree water film on metal surfaces are

generally satisfactory.

A. Aluminum (optimized FPL etch – 3M Company Test Method C-2803 or ASTM

D 2651).

equivalent solution 9-11 oz/gallon water at 190 ± 10°F for 10-20 minutes.

Rinse immediately in large quantities of cold running water.

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.

Place panels in FPL etch solution heated to 150-160°F (66-71°C) for 12-15

minutes.

Note: Review and follow safety and precautionary information provided by

chemical supplier prior to preparation of this etch solution.

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

4. Dry – Air dry 15 minutes; force dry 10 minutes minimum at 140°F (60°C)

maximum.

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

preparation.

B. Aluminum Honeycomb Core

1. Soak in clean Aliphatic Naphtha (TT-N-95A) for five minutes at room

temperature. Dry for 10 minutes minimum at 140°F (60°C) maximum.

2. Optional – Immerse in FPL etching solutions for two (2) minutes at 155 ± 5°F.

Rinse, air dry and force dry in similar manner to skin panels.