NACE - National Association of Corrosion Engineers Protective Coatings and Linings Questions and Answers

Question 1

According to the joint standard NACE No. 1 / SSPC-SP 5, what is the required condition of a steel surface after 'White Metal Blast Cleaning'?

Accepted Answer

The surface, when viewed without magnification, must be free of all visible oil, grease, dust, dirt, mill scale, rust, coating, oxides, and other foreign matter.

Answer

The surface must be free of all visible oil, grease, and dirt, but tightly adherent mill scale and rust may remain on up to 5% of the surface.

Answer

The surface must be cleaned to a near-white metal condition, with no more than 33% of each square inch of surface area containing light shadows, streaks, or minor discolorations.

Answer

The surface must be prepared using high-pressure water jetting to remove all contaminants, exposing the original blasted surface profile.

Question 2

An inspector is measuring the dry film thickness (DFT) of a coating on a 500 sq ft steel tank section according to SSPC-PA 2. How are the spot and area measurements correctly performed?

Accepted Answer

Take five spot measurements (each an average of at least 3 readings) over each 100 sq ft area, and the average of these five spots constitutes the area measurement.

Answer

Take one gage reading per 100 sq ft area, and the average of all readings must meet the specification.

Answer

Take one spot measurement (average of 3 readings) in the center of each 100 sq ft area; all spot measurements must be within specification.

Answer

Take three gage readings anywhere within the 500 sq ft section and average them to get the final DFT.

Question 3

A pipeline operating under impressed current cathodic protection (CP) has its fusion-bonded epoxy (FBE) coating tested. The test involves creating an intentional holiday and applying a negative potential in an electrolyte to measure the coating's resistance to delamination. What is this test called?

Accepted Answer

Cathodic Disbondment Test (ASTM G8/G42/G95)

Answer

Adhesion Pull-Off Test (ASTM D4541)

Answer

Holiday Detection Test (ASTM G62)

Answer

Abrasion Resistance Test (ASTM D4060)

Question 4

Which of the following best describes the primary corrosion protection mechanism of an inorganic zinc-rich primer on a steel substrate?

Accepted Answer

It provides sacrificial (galvanic) protection by corroding preferentially to the steel substrate.

Answer

It forms a non-porous, impermeable barrier that prevents electrolytes from reaching the steel.

Answer

It passivates the steel surface by forming a thin, non-reactive oxide layer.

Answer

It releases chemical inhibitors that neutralize corrosive agents at the steel surface.

Question 5

An epoxy coating applied in a cool, humid environment develops a waxy, greasy film on the surface after curing. This defect, which can cause intercoat adhesion failure, is most likely:

Accepted Answer

Amine Blush

Answer

Chalking

Answer

Cratering

Answer

Orange Peel

Question 6

An inspector needs to perform a holiday test on a 15-mil (380-micron) thick tank lining. Which of the following methods is most appropriate and effective for detecting holidays in a coating of this thickness?

Accepted Answer

High-voltage (spark) holiday detector set to an appropriate voltage based on the coating thickness.

Answer

Low-voltage (wet-sponge) holiday detector set to 67.5V.

Answer

Visual inspection with high-powered magnification.

Answer

Solvent wipe test using a contrasting color solvent.