Glass Testing Methods

Boiling Test Procedure

1. A sample is cut from a job lot, or made specifically for testing at the same time as the job. Thickness of glass is irrelevant.

2. The sample piece is left to cure for 72 hours.

3. The sample is to be crosshatched as follows:

  • 10 vertical lines 2 mm apart are cut into the paint surface using a razor blade, each line being approximately 50 mm in length.
  • 10 horizontal lines are then cut across the verticals, 2 mm apart and 50 mm in length.

4. The crosshatched sample is immersed vertically in water (55 degrees Celsius) for 3 minutes.

5. The sample is then transferred without delay and immersed in boiling water for a period of 2 hours.

6. The sample panel is then removed from the boiling water and examined for defects.

7. The crosshatched panel is then left for 24 hours.

8. Firmly apply 100 mm of strong adhesive tape to the crosshatched area, leave for 30 minutes then peel the tape off slowly and examine the tape for paint particles.

Boil test assessment criteria.

  • Acceptable - Over 80% of paint left on glass in crosshatched area.
  • Excellent - No paint is removed from crosshatched area.