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AMPP CP3 Technologist practice questions

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Question 1Corrosion Fundamentals and Coating Science

In the electrochemical corrosion of iron in an aerated neutral solution, which reaction occurs at the cathodic sites?

  1. O₂ + 2H₂O + 4e⁻ → 4OH⁻ Correct answer.
  2. Fe → Fe²⁺ + 2e⁻
  3. 2H₂O → O₂ + 4H⁺ + 4e⁻
  4. Fe²⁺ → Fe³⁺ + e⁻

Explanation

At cathodes, reduction consumes the electrons released by anodic metal dissolution. In aerated neutral water the dominant cathodic reaction is oxygen reduction, producing hydroxide ions. Metal dissolution and oxygen evolution are oxidation reactions that occur at anodes.

Question 2Corrosion Fundamentals and Coating Science

A galvanic couple is formed between two metals in seawater. Which combination places the less noble metal at greater risk of accelerated corrosion?

  1. Two metals with nearly identical electrode potentials
  2. A small cathode area coupled to a large anode area
  3. A large cathode area coupled to a small anode area Correct answer.
  4. Equal cathode and anode areas with identical metals

Explanation

Galvanic corrosion severity increases when the cathodic area is large relative to the anodic area, because the anode must supply a high current density over a small area. This concentrates dissolution and accelerates metal loss at the anode. Equal areas or similar potentials produce little driving force.

Question 3Corrosion Fundamentals and Coating Science

Which statement best describes the role of a coating in interrupting a corrosion cell?

  1. It supplies sacrificial electrons to the substrate.
  2. It permanently eliminates all oxygen from the environment.
  3. It raises the electrochemical potential of the substrate above the cathodic reaction.
  4. It acts as a barrier that limits electrolyte contact and ionic current flow. Correct answer.

Explanation

A barrier coating isolates the substrate from the electrolyte and impedes the ionic and electronic pathways needed for a corrosion cell. It does not normally supply sacrificial current unless it contains conductive pigment, and it cannot remove oxygen from the environment.

Question 4Corrosion Fundamentals and Coating Science

What is the primary function of a zinc-rich primer in a protective coating system on steel?

  1. To act as a sacrificial anode that protects exposed steel. Correct answer.
  2. To increase the flexibility of the topcoat.
  3. To provide color and gloss to the finish.
  4. To serve as a solvent reservoir for the topcoat.

Explanation

Zinc-rich primers contain sufficient zinc particles in electrical contact to act galvanically, sacrificially protecting steel at breaks and scratches. The zinc is anodic to steel and corrodes preferentially. Color, gloss, and flexibility are functions of other layers.

Question 5Corrosion Fundamentals and Coating Science

A steel structure shows severe pitting while the surrounding surface remains largely intact. Which condition most favors this localized attack?

  1. Uniform electrolyte coverage with even oxygen access
  2. Complete absence of any electrolyte on the surface
  3. A coating with no defects over the entire surface
  4. A passive film with localized breaks in an aggressive chloride environment Correct answer.

Explanation

Pitting occurs where a passive or protective film is locally disrupted, often by chlorides, creating a small anode surrounded by a large passive cathode. The resulting geometry concentrates dissolution at the pit. Uniform coverage or absence of electrolyte does not produce this localization.

Question 6Corrosion Fundamentals and Coating Science

Which factor most directly increases the rate of oxygen diffusion to a cathodic surface in an immersion environment?

  1. Adding a corrosion inhibitor to the bulk solution
  2. Increasing the water velocity at the metal surface Correct answer.
  3. Increasing the pH to strongly alkaline levels
  4. Decreasing the water temperature near freezing

Explanation

Oxygen reduction is often diffusion-controlled, so thinning the diffusion boundary layer by increasing flow raises the oxygen arrival rate. Higher velocity replenishes dissolved oxygen at the cathode. Temperature and inhibitor additions affect other variables rather than the diffusion boundary layer in this way.

Question 7Corrosion Fundamentals and Coating Science

What does the term 'holiday' mean in coating inspection?

  1. A discontinuity or void in a coating film exposing the substrate Correct answer.
  2. The overcoat window between coats
  3. The gloss level of the cured finish
  4. A scheduled pause in the application process

Explanation

A holiday is a small discontinuity, pinhole, or void in a coating that leaves the substrate exposed or inadequately covered. Such defects are located with high-voltage or low-voltage holiday detectors. They are not scheduling pauses or appearance measures.

Question 8Corrosion Fundamentals and Coating Science

Which surface preparation condition most improves the mechanical adhesion of a coating to steel?

  1. A surface wetted with condensation
  2. An angular, roughened surface profile Correct answer.
  3. A surface contaminated with residual oil
  4. A polished, mirror-smooth surface

Explanation

An angular surface profile increases the effective contact area and provides mechanical keying for the coating. Smooth surfaces offer little anchorage, while oil and moisture interfere with wetting and adhesion.

Question 9Corrosion Fundamentals and Coating Science

A coating blisters in service with liquid-filled domes over areas of soluble contamination. Which mechanism best explains this failure?

  1. Abrasive wear from airborne particles
  2. Ultraviolet degradation of the binder
  3. Thermal expansion mismatch of the substrate
  4. Osmotic blistering driven by a concentration gradient across the film Correct answer.

Explanation

Soluble salts or contaminants under a coating create a concentration gradient that draws water through the semipermeable film by osmosis, forming liquid-filled blisters. The blister forms at the contamination site. Abrasion, UV, and thermal effects produce different failure signatures.

Question 10Corrosion Fundamentals and Coating Science

Which of the following best describes cathodic disbondment of a coating on steel?

  1. Discoloration of the coating from sunlight exposure
  2. Softening of the film from solvent retention
  3. Loss of adhesion caused by mechanical impact
  4. Loss of adhesion propagating from a defect where cathodic reactions generate alkalinity Correct answer.

Explanation

At coating defects under cathodic protection or galvanic coupling, oxygen reduction produces hydroxide, raising local pH. This alkaline environment degrades the coating bond and disbondment spreads outward from the defect. Mechanical impact and UV cause different effects.

Question 11Corrosion Fundamentals and Coating Science

Which property of a coating binder most directly governs its resistance to permeation by water vapor?

  1. Surface gloss of the cured film
  2. Crosslink density and polymer chemistry Correct answer.
  3. Pigment particle color
  4. Solvent evaporation rate during application

Explanation

Permeation resistance depends on the polymer network, particularly crosslink density and chemistry, which control how easily water molecules diffuse through the film. Pigment color and gloss do not determine permeability, and solvent evaporation affects application rather than the cured barrier.

Question 12Corrosion Fundamentals and Coating Science

During application, a coating is exposed to conditions below the dew point of the surrounding air. What is the most likely consequence?

  1. Improved adhesion from moisture curing
  2. Increased film thickness from water absorption
  3. Faster cure due to higher humidity
  4. Condensation on the substrate causing poor adhesion or blistering Correct answer.

Explanation

When surface temperature falls below the dew point, moisture condenses on the substrate, interfering with wetting and trapping water under the film. This leads to poor adhesion, blistering, or early failure. Condensation does not improve adhesion or cure for conventional coatings.

Question 13Corrosion Fundamentals and Coating Science

Which statement correctly distinguishes anodic from cathodic protection?

  1. Anodic protection raises the potential into the passive region; cathodic protection supplies electrons to lower the potential. Correct answer.
  2. Both methods require the metal to remain in the active corrosion region.
  3. Anodic protection supplies electrons; cathodic protection removes electrons.
  4. Both methods work by adding chloride to the electrolyte.

Explanation

Anodic protection shifts the metal potential into a stable passive range where dissolution is low. Cathodic protection instead supplies electrons so the metal becomes the cathode and anodic dissolution stops. The two rely on opposite potential shifts.

Question 14Corrosion Fundamentals and Coating Science

A coating system shows chalking and gloss loss after prolonged outdoor exposure. Which degradation mechanism is most likely responsible?

  1. Ultraviolet radiation breaking down the binder at the surface Correct answer.
  2. Abrasion from windblown sand
  3. Osmotic blistering from soluble salts
  4. Cathodic disbondment at a defect

Explanation

Ultraviolet radiation degrades the polymer binder at the exposed surface, leaving pigment particles loosely bound, which appears as chalking and gloss loss. This is a surface photodegradation effect. Blistering, disbondment, and abrasion produce different visible damage.

Question 15Corrosion Fundamentals and Coating Science

Which of the following is the best example of a conversion coating used to improve paint adhesion and corrosion resistance on steel?

  1. A phosphate conversion coating Correct answer.
  2. A zinc-rich primer
  3. An epoxy intermediate coat
  4. A polyurethane topcoat

Explanation

Conversion coatings chemically alter the metal surface, forming a phosphate or similar layer that improves adhesion and adds corrosion resistance. Primers, intermediate coats, and topcoats are applied organic layers rather than surface conversion treatments.

Question 16Corrosion Fundamentals and Coating Science

In a corrosion cell, what is the function of the electrolyte?

  1. It generates the potential difference between the two metals.
  2. It supplies the metal ions that form the anode.
  3. It prevents electron flow in the external circuit.
  4. It provides a conductive path for ionic current between anode and cathode. Correct answer.

Explanation

The electrolyte is an ionic conductor that completes the circuit by carrying ions between anodic and cathodic regions. The metal itself supplies the ions during dissolution, and the potential difference arises from the metals' electrochemistry, not the electrolyte.

Question 17Corrosion Fundamentals and Coating Science

Which condition would most likely shift a steel surface from uniform corrosion to crevice corrosion?

  1. A completely dry, clean surface
  2. Fully open, well-agitated exposure
  3. A tight gap under a gasket or lap joint where oxygen is depleted Correct answer.
  4. A high-velocity flow that constantly replenishes oxygen

Explanation

In a tight crevice, oxygen inside is consumed and cannot be replenished, creating an oxygen concentration cell. The shielded region becomes anodic and corrodes while the open surface remains cathodic. Open, agitated, or dry conditions do not create this differential.

Question 18Corrosion Fundamentals and Coating Science

Which statement best explains why a thicker coating does not always give proportionally better barrier protection?

  1. Barrier protection is independent of film thickness.
  2. Thicker films cannot adhere to prepared steel.
  3. Internal stresses and curing defects can increase with thickness, creating pathways for permeation. Correct answer.
  4. Thicker films always have more defects per unit area.

Explanation

Increasing thickness can raise internal stress, solvent retention, and curing-related defects, which may offset the added barrier. Permeation resistance does improve with thickness up to a point, but defect formation can limit the benefit. Thickness alone is not a guarantee of performance.

Question 19Corrosion Fundamentals and Coating Science

Which of the following best describes the mechanism by which an inhibitive pigment in a primer protects steel?

  1. It provides sacrificial current like zinc dust.
  2. It physically blocks all water from reaching the metal.
  3. It slowly releases species that passivate or suppress the corrosion reaction at the metal surface. Correct answer.
  4. It increases the gloss of the coating.

Explanation

Inhibitive pigments release sparingly soluble species that interfere with anodic or cathodic reactions, forming a protective or passivating layer at the metal. They do not rely on complete physical blocking or on sacrificial galvanic action. Gloss is unrelated to this mechanism.

Question 20Corrosion Fundamentals and Coating Science

Which measurement would best indicate whether a coating has sufficient adhesion to withstand service stresses?

  1. A pull-off adhesion test after the film has cured Correct answer.
  2. Gloss measurement at 60 degrees
  3. Color match against a standard
  4. Wet film thickness measured during application

Explanation

A pull-off adhesion test quantifies the force required to detach the coating, directly reflecting bond strength. Wet film thickness, gloss, and color describe application and appearance rather than adhesion.

Question 21Corrosion Fundamentals and Coating Science

Which electrochemical condition corresponds to the immunity region of a Pourbaix diagram for iron?

  1. Potentials where iron dissolves rapidly regardless of pH
  2. Potentials where iron forms a soluble ferrate species
  3. Potentials where iron is stable as a metal and does not dissolve Correct answer.
  4. Potentials where iron forms soluble ferrous ions

Explanation

The immunity region represents potentials at which the metal is thermodynamically stable and does not dissolve. Soluble ion regions correspond to active corrosion, and passive regions correspond to stable oxide films. Immunity is distinct from passivity.

Question 22Corrosion Fundamentals and Coating Science

Which factor most strongly influences the rate of drying and curing of a solvent-borne coating applied in the field?

  1. The gloss of the substrate
  2. The color of the pigment
  3. The ambient temperature, humidity, and airflow Correct answer.
  4. The thickness of the steel substrate only

Explanation

Solvent evaporation and cure depend on temperature, humidity, and airflow, which control solvent loss and reaction rates. Pigment color and substrate gloss do not govern drying. Substrate thickness has only an indirect thermal effect compared with ambient conditions.

Question 23Corrosion Fundamentals and Coating Science

Which statement about the difference between a passivating oxide film and a barrier coating is correct?

  1. A barrier coating forms by oxidation of the substrate metal.
  2. A passive film is a naturally formed or chemically grown thin oxide, while a barrier coating is an applied layer. Correct answer.
  3. A passive film provides no corrosion protection.
  4. Both are applied organic layers of similar thickness.

Explanation

Passive films are thin oxides that form naturally or through chemical treatment and reduce dissolution. Barrier coatings are applied layers that block the electrolyte. They differ in origin and thickness, and passive films do provide protection.

Question 24Corrosion Fundamentals and Coating Science

A coated steel tank shows disbondment that follows the pattern of a poorly prepared lap joint and worsens where the coating is immersed. Which combination of factors best explains this?

  1. Thermal expansion of the steel substrate alone
  2. Soluble contamination in the lap plus water permeation driving osmotic and crevice effects Correct answer.
  3. Abrasion from moving liquid alone
  4. UV exposure and chalking of the topcoat

Explanation

Contamination trapped in the lap creates a concentration gradient that draws water through the film, while the shielded geometry promotes crevice conditions and local alkalinity. Together these accelerate disbondment at the lap. UV, abrasion, or thermal effects do not explain the contamination-following pattern.

Question 25Surface Preparation Standards and Methods

Under SSPC-SP 5/NACE No. 1, a white metal blast cleaned surface is defined as one that is free of all visible oil, grease, dust, dirt, mill scale, rust, coating, oxides, corrosion products, and what other visible contaminants?

  1. Loose zinc dust
  2. Any other foreign matter Correct answer.
  3. Anchor profile peaks
  4. Visible mill scale residue

Explanation

SSPC-SP 5 requires removal of all visible contaminants including oil, grease, dust, dirt, mill scale, rust, coating, oxides, and corrosion products, leaving a uniformly gray-white surface. Any other visible foreign matter must also be removed.

Question 26Surface Preparation Standards and Methods

Which SSPC surface preparation standard describes a commercial blast cleaned surface that permits staining on no more than 33 percent of the surface area?

  1. SSPC-SP 10/NACE No. 2
  2. SSPC-SP 14/NACE No. 8
  3. SSPC-SP 7/NACE No. 4
  4. SSPC-SP 6/NACE No. 3 Correct answer.

Explanation

SSPC-SP 6/NACE No. 3 defines commercial blast cleaning, which allows staining limited to no more than 33 percent of the unit area. Near-white (SP 10) is more restrictive and brush-off (SP 7) is less restrictive.

Question 27Surface Preparation Standards and Methods

A specification requires a near-white metal blast finish. Which combination of standards correctly identifies that grade?

  1. SSPC-SP 5/NACE No. 1
  2. SSPC-SP 7/NACE No. 4
  3. SSPC-SP 6/NACE No. 3
  4. SSPC-SP 10/NACE No. 2 Correct answer.

Explanation

Near-white metal blast cleaning is designated SSPC-SP 10 and is equivalent to NACE No. 2. It allows staining on no more than 5 percent of each unit area.

Question 28Surface Preparation Standards and Methods

What does the term 'unit area' mean when applying SSPC visual standards for blast cleaning?

  1. The area within one meter of a weld
  2. A representative area of defined size used to judge staining limits Correct answer.
  3. The entire surface of one fabricated structure
  4. The area covered by one bag of abrasive

Explanation

SSPC visual standards evaluate staining against a defined representative area called a unit area, typically a specified square area. Staining limits are expressed as a percentage of that unit area rather than of the entire structure.

Question 29Surface Preparation Standards and Methods

Abrasive blasting is performed and the resulting surface has a profile that is too shallow for the specified coating. Which change to the abrasive is most likely to increase the anchor profile?

  1. Reducing the blast nozzle pressure
  2. Using a larger, more angular abrasive at the same pressure Correct answer.
  3. Using a finer mesh abrasive at the same pressure
  4. Increasing the standoff distance significantly

Explanation

Profile depth is influenced by abrasive size, shape, hardness, and velocity. Larger angular abrasive particles create deeper anchor patterns than finer or rounded media at comparable pressure.

Question 30Surface Preparation Standards and Methods

Which abrasive type is classified as a naturally occurring mineral abrasive commonly used for blast cleaning?

  1. Copper slag
  2. Aluminum oxide
  3. Steel shot
  4. Garnet Correct answer.

Explanation

Garnet is a naturally occurring mineral abrasive used in blast cleaning. Steel shot is a metallic abrasive, copper slag is a smelting by-product, and aluminum oxide is a manufactured abrasive.

Question 31Surface Preparation Standards and Methods

Why is compressed air used for abrasive blasting required to be free of oil and moisture?

  1. To prevent contamination of the prepared surface and clogging of the abrasive flow Correct answer.
  2. To lower the electrical conductivity of the surface
  3. To reduce the noise level of the nozzle
  4. To increase the hardness of the abrasive

Explanation

Oil and moisture in the blast air can deposit contaminants on the freshly prepared substrate and interfere with abrasive flow. Clean, dry air is required to protect the prepared surface and maintain consistent blasting.

Question 32Surface Preparation Standards and Methods

A specification requires a brush-off blast cleaned surface. Which standard applies?

  1. SSPC-SP 7/NACE No. 4 Correct answer.
  2. SSPC-SP 5/NACE No. 1
  3. SSPC-SP 6/NACE No. 3
  4. SSPC-SP 10/NACE No. 2

Explanation

Brush-off blast cleaning is SSPC-SP 7/NACE No. 4, the least thorough of the abrasive blast standards. It removes loose material but permits tightly adherent mill scale and coatings to remain.

Question 33Surface Preparation Standards and Methods

Hand tool cleaning and power tool cleaning are addressed by which pair of SSPC standards?

  1. SSPC-SP 3 and SSPC-SP 6
  2. SSPC-SP 11 and SSPC-SP 12
  3. SSPC-SP 1 and SSPC-SP 2
  4. SSPC-SP 2 and SSPC-SP 3 Correct answer.

Explanation

SSPC-SP 2 covers hand tool cleaning and SSPC-SP 3 covers power tool cleaning. SP 1 addresses solvent cleaning, and SP 11/SP 12 address power tool cleaning to bare metal and water jetting respectively.

Question 34Surface Preparation Standards and Methods

Which SSPC standard specifically describes power tool cleaning to produce a bare substrate surface?

  1. SSPC-SP 11 Correct answer.
  2. SSPC-SP 3
  3. SSPC-SP 15
  4. SSPC-SP 2

Explanation

SSPC-SP 11 covers power tool cleaning to bare metal, which removes all visible coatings and contaminants to expose the substrate. SSPC-SP 3 is general power tool cleaning that does not require bare metal.

Question 35Surface Preparation Standards and Methods

Solvent cleaning to remove oil, grease, soil, and similar contaminants before other surface preparation is covered by which SSPC standard?

  1. SSPC-SP 16
  2. SSPC-SP 13
  3. SSPC-SP 1 Correct answer.
  4. SSPC-SP 2

Explanation

SSPC-SP 1 covers solvent cleaning, which removes oil, grease, dirt, soil, salts, and similar contaminants. It is typically performed before mechanical surface preparation.

Question 36Surface Preparation Standards and Methods

Water jetting standards use a numerical designation for the degree of cleaning. What does the 'WJ-2' designation represent?

  1. A low-pressure wash with no surface disruption
  2. A high-pressure water jet that removes loose material but leaves tightly adherent coatings Correct answer.
  3. A water jet finish that removes all visible coatings and leaves a matte finish
  4. A near-white water jet finish with 95 percent bare substrate

Explanation

In the NACE/SSPC water jetting system, WJ-2 is a high-pressure cleaning that removes loose material while permitting tightly adherent coatings and mill scale to remain. WJ-1 is the most thorough and WJ-4 the least.

Question 37Surface Preparation Standards and Methods

Which water jetting designation corresponds to a surface with no visible contaminants and a matte finish, equivalent in cleanliness to white metal?

  1. WJ-3
  2. WJ-4
  3. WJ-2
  4. WJ-1 Correct answer.

Explanation

WJ-1 is the most thorough water jetting grade, producing a clean surface with a matte finish and no visible contaminants, comparable to white metal blast. WJ-2 through WJ-4 are progressively less thorough.

Question 38Surface Preparation Standards and Methods

A contractor must remove soluble salts from a steel surface before coating. Which test method is commonly used to quantify chloride contamination on the surface?

  1. Holiday detection
  2. Tape adhesion test
  3. Pull-off adhesion test
  4. Bresle patch method Correct answer.

Explanation

The Bresle patch method extracts soluble salts from a defined surface area and analyzes the solution for chloride concentration. Adhesion and holiday tests evaluate coating integrity, not salt contamination.

Question 39Surface Preparation Standards and Methods

Which condition is most likely to cause a coating failure if soluble salts are left on a blast-cleaned surface?

  1. Higher abrasion resistance
  2. Increased coating gloss
  3. Improved adhesion through ionic bonding
  4. Osmotic blistering and premature disbondment Correct answer.

Explanation

Residual soluble salts draw moisture through the coating by osmosis, leading to blistering and disbondment. Cleanliness testing and removal of salts are therefore required before coating application.

Question 40Surface Preparation Standards and Methods

Abrasive blasting with a centrifugal wheel machine is best described as which type of blast cleaning?

  1. Wet blast cleaning
  2. Centrifugal (wheel) blast cleaning Correct answer.
  3. Vacuum blast cleaning
  4. Air blast cleaning

Explanation

Centrifugal blast cleaning uses a rotating wheel to propel abrasive at high velocity, distinguishing it from compressed-air blasting. It is commonly used in shop or automatic blasting operations.

Question 41Surface Preparation Standards and Methods

What is the primary purpose of establishing an anchor profile on a blast-cleaned steel surface?

  1. To remove soluble salts from the substrate
  2. To provide mechanical keying for the coating system Correct answer.
  3. To increase the electrical conductivity of the steel
  4. To reduce the surface area available for coating

Explanation

Anchor profile creates a roughened surface that promotes mechanical adhesion of the coating. It is measured separately from cleanliness, and both must meet specification.

Question 42Surface Preparation Standards and Methods

Which instrument is used to measure surface profile by replicating the surface texture?

  1. Magnetic thickness gauge
  2. Holiday detector
  3. Wet film gauge
  4. Surface comparator (replica tape) Correct answer.

Explanation

Replica tape pressed onto the surface captures the profile, and the compressed tape is measured with a micrometer to quantify profile depth. Wet film gauges and DFT gauges measure coating thickness, not profile.

Question 43Surface Preparation Standards and Methods

A specification calls for SSPC-SP 6 commercial blast cleaning. Which statement best describes the acceptable surface?

  1. No more than 33 percent staining per unit area, with removal of all oil, grease, dirt, and loose mill scale Correct answer.
  2. Intact tight mill scale permitted over most of the surface
  3. All visible contaminants removed with a uniform gray-white finish
  4. No more than 5 percent staining per unit area

Explanation

SP 6 commercial blast cleaning requires removal of oil, grease, dirt, and loose mill scale and rust, with staining limited to 33 percent of each unit area. It is less thorough than SP 10.

Question 44Surface Preparation Standards and Methods

Which of the following best describes the difference between SSPC-SP 2 and SSPC-SP 3?

  1. SP 2 is solvent cleaning and SP 3 is hand tool cleaning
  2. SP 2 is blast cleaning and SP 3 is water jetting
  3. SP 2 is hand tool cleaning and SP 3 is power tool cleaning Correct answer.
  4. SP 2 is power tool cleaning and SP 3 is hand tool cleaning

Explanation

SSPC-SP 2 covers hand tool cleaning using non-powered tools, while SSPC-SP 3 covers power tool cleaning using powered equipment. Both remove loose material but differ in the tools employed.

Question 45Surface Preparation Standards and Methods

After abrasive blasting, a surface shows a uniform gray-white appearance with no visible staining. Which SSPC grade does this most closely represent?

  1. SSPC-SP 6
  2. SSPC-SP 7
  3. SSPC-SP 5 Correct answer.
  4. SSPC-SP 10

Explanation

A uniform gray-white surface free of visible staining meets white metal blast cleaning, SSPC-SP 5/NACE No. 1. Near-white (SP 10) permits up to 5 percent staining.

Question 46Surface Preparation Standards and Methods

Which factor has the greatest influence on the depth of anchor profile produced during abrasive blasting?

  1. Abrasive size and shape Correct answer.
  2. Coating type to be applied
  3. Color of the substrate
  4. Ambient relative humidity

Explanation

Profile depth is primarily controlled by abrasive characteristics such as particle size, shape, and hardness, along with blast parameters. Humidity and coating type affect other aspects of the job but not profile formation.

Question 47Surface Preparation Standards and Methods

A steel surface has been prepared to SSPC-SP 10. Which statement about the permitted staining is correct?

  1. Staining is permitted on up to 33 percent of each unit area
  2. Staining is permitted on up to 5 percent of each unit area Correct answer.
  3. No staining is permitted anywhere
  4. Staining is permitted on up to 50 percent of each unit area

Explanation

SSPC-SP 10 near-white blast cleaning limits staining to no more than 5 percent of each unit area. This is stricter than SP 6 but less strict than SP 5.

Question 48Surface Preparation Standards and Methods

Which of the following is a key limitation of hand and power tool cleaning compared with abrasive blasting?

  1. It cannot be used on ferrous metals
  2. It generally does not produce the same degree of cleanliness or profile as blast cleaning Correct answer.
  3. It cannot remove oil and grease
  4. It is always more expensive than blasting

Explanation

Hand and power tool cleaning remove loose material but generally do not achieve the cleanliness or anchor profile produced by abrasive blasting. Solvent cleaning, not tool cleaning, addresses oil and grease.

Question 49Surface Preparation Standards and Methods

A specification requires removal of all visible oil, grease, and dirt before abrasive blasting. Which SSPC standard should be performed first?

  1. SSPC-SP 6
  2. SSPC-SP 5
  3. SSPC-SP 1 Correct answer.
  4. SSPC-SP 10

Explanation

SSPC-SP 1 solvent cleaning removes oil, grease, dirt, and similar contaminants and is typically performed before mechanical surface preparation. Blasting over oil or grease can drive contaminants into the surface.

Question 50Surface Preparation Standards and Methods

A specification requires a surface prepared by abrasive blasting to achieve a 'near-white' finish. Which SSPC/NACE surface preparation standard corresponds to this requirement?

  1. SSPC-SP 7/NACE No. 4
  2. SSPC-SP 10/NACE No. 2 Correct answer.
  3. SSPC-SP 5/NACE No. 1
  4. SSPC-SP 6/NACE No. 3

Explanation

SSPC-SP 10/NACE No. 2 is the near-white blast cleaning standard, permitting only very light staining on no more than 5% of each unit area. It is less thorough than white metal (SP 5) but more thorough than commercial blast (SP 6).