General Contractor Practice Exam

What is the recommended pressure for sandblasting with a 1/4 inch nozzle?

1. 30-50 PSI

2. 50-70 PSI

3. 60-120 PSI

4. 120-150 PSI

The correct answer is: 60-120 PSI

The recommended pressure for sandblasting with a 1/4 inch nozzle typically falls within the range of 60-120 PSI. This pressure range is considered optimal because it provides the necessary force to propel the abrasive material effectively while ensuring an even and controlled blast. Using this pressure allows for efficient removal of surface contaminants, such as rust and old paint, without damaging the underlying material. If the pressure is too low, the abrasive material may not achieve adequate velocity, resulting in incomplete surface preparation. Conversely, if the pressure is too high, it could lead to excessive wear on the nozzle and an increased risk of damage to the substrate being worked on. Understanding the correct pressure settings is crucial for effective sandblasting practices and helps ensure that safety protocols are followed to prevent accidents or failures during the blasting process. The other ranges do not typically align with standard practices, as options that suggest significantly lower or higher pressures may not achieve the intended results effectively or could pose safety risks.