Structural Adhesive Primer

EC-2174

- 2 -

Surface

Preparation

A. Aluminum (3M Company Optimized FPL Etch-AC&S Test Method C-2803)

1. Vapor Degrease – Perchloroethylene condensing vapors for 5-10 minutes.

2. 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.

3. Acid Etch* – Place panels in the following solution for 10 minutes at 150°F ± 5°F

(66°C ± 2°C).

4.1 - 4.9 oz./gallon

Sulfuric Acid, 66° Be

38.5 - 41.5 oz./gallon

2024T-3 aluminum (dissolved)

0.2 oz./gallon minimum

Tap Water as needed to balance

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

5. Dry – Air dry 15 minutes; force dry 10 minutes at 150°F ± 10°F (66°C ± 5°C).

6. It is advisable to coat the freshly cleaned surfaces with 3M™ Scotch-Weld™

Structural Adhesive Primer EC-2174 within four hours after surface preparation.

7. Care should be taken to avoid contaminating the cleaned aluminum by any

substance which will hinder the wetting action of Scotch-Weld EC-2174.

B. Stainless Steel (17 - 7PH TH 1050)

2. Vapor Degrease – Perchloroethylene condensing vapors for 5-10 minutes.

3. Acid Etch* – Place panels in the following solution for 2 minutes at 145°F ± 5°F

(63°C ± 2°C).

59.9 gms M.F. Acid (Wyandotte) 170 mls. Commercial Concentrated Nitric Acid.

The balance of 1 liter of distilled water.

4. Rinse – Rinse immediately in cold running tap water. Remove smut with a distilled

water-air spray under 90 psi pressure.

5. Acid Etch – Place panels in the following solution for 5 minutes at 160°F ± 5°F

(71°C ± 2°C).

30 parts by wt. distilled water

10 parts by wt. concentrated sulfuric acid

4 parts by wt. sodium dichromate

6. Rinse in cold tap water. Remove smut with a distilled water – air spray under 90 psi

pressure.

7. Dry – Air dry 15 minutes; force dry 10 minutes at 160°F ± 5°F (71°C ± 2°C).

8. It is advisable to coat the freshly cleaned surfaces with Scotch-Weld EC-2174 within

1 hour after surface preparation.

9. Care should be taken to avoid contaminating the cleaned steel surface by any

substance which will hinder the wetting action of Scotch-Weld EC-2174.

*CAUTION: Use adequate respiratory, eye and skin protection when using etch solutions.

Primer Application:

The following procedure is suggested to obtain optimum results.

Method: Brush, flow, or dip coat to .0004-.0006 inches dry.