20 Contamination & Adhesion Problems Practice Questions & Answers

1. 1. A shop finds fine dirt nibs in the clearcoat on every vehicle painted this week, and the booth gauge shows an unusually high pressure drop across the intake filters. What is the most likely source of the dirt?

   • A.Loaded intake filters starving the booth so unfiltered air leaks in at door gaps✓ Answer
   • B.Rust and scale from the air lines reaching the gun through a missing filter
   • C.Unstrained clearcoat leaving gelled particles in the film on every vehicle
   • D.Lint shed from the painter's cotton coveralls during each spray session

   A high pressure drop across the intake filters means they are loaded with dirt and restrict the air entering the booth. The booth then runs at negative pressure and pulls unfiltered shop air in through door gaps, so every job picks up dirt. Unstrained material, lint or air-line scale would not change the filter pressure reading, so the gauge points to the filters, which must be replaced on schedule.

   Ref QB-SECKSQSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify dirt in the refinished surface and determine its source (spray booth filtration and pressure)Report a problem with this question

2. 2. After a quarter-panel refinish, dirt nibs are concentrated in the clearcoat near the door opening and along the body seam, while the rest of the panel is clean. Which prep step was most likely skipped?

   • A.Switching off booth airflow while spraying so dust stays still
   • B.Spraying a heavier first coat to lock loose dust onto the panel
   • C.Blowing out the door jamb and seams with air before tacking✓ Answer
   • D.Adding a slower reducer so the dust sinks below the surface

   Dirt clustered at the door opening and seams comes from the vehicle itself: debris trapped in jambs and seams is blown out by the gun's air while spraying. Blowing these areas out before the final tack wipe removes it. Heavier coats, a slower reducer or shutting off booth airflow do not remove the dirt and create other defects.

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3. 3. A fully cured clearcoat has a few isolated dirt nibs. Painter A says to nib-sand them with a very fine abrasive and then compound and polish the spots. Painter B says any dirt in the clear means the whole panel must be resanded and recleared. Who is right?

   • A.B only
   • B.Both A and B
   • C.Neither A nor B
   • D.A only✓ Answer

   Only Painter A is right. A few isolated nibs in cured clear are corrected by denibbing with a very fine abrasive and then compounding and polishing to restore gloss. Resanding and reclearing the panel is needed only when the dirt is too heavy or too deep to sand out without cutting through the clear.

   Ref QB-TEQWXRSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify dirt in the refinished surface and correct the conditionReport a problem with this question

4. 4. All of these help keep dirt and foreign matter out of a fresh refinish EXCEPT:

   • A.Replacing booth intake and exhaust filters on schedule
   • B.Propping the booth doors open to pull in extra airflow✓ Answer
   • C.Straining every material as it is poured into the gun cup
   • D.Wearing a lint-free paint suit while working in the booth

   Propping the booth doors open lets unfiltered shop air and dust bypass the booth filtration, so it adds dirt rather than preventing it. Straining all materials, wearing a lint-free paint suit and maintaining the booth filters each remove a known source of dirt: the material, the painter and the booth.

   Ref QB-7XFRUMSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify dirt in the refinished surface, determine its source and correct the conditionReport a problem with this question

5. 5. During the first coat of clear on a door, small round craters open up where the paint pulls away from the surface. The customer had been using a silicone protectant on the car. What should the painter do first?

   • A.Add extra reducer to the clear so it can level out over the craters
   • B.Stop, let it flash, then apply light mist coats to bridge the craters✓ Answer
   • C.Raise the gun's air pressure so finer droplets can fill the craters
   • D.Keep spraying full wet coats so the clear flows back into the craters

   Fish-eyes come from surface contamination such as silicone, which lowers surface tension so the wet paint pulls away. Wetter or more heavily reduced material only pulls away more. Stopping, letting the film flash and then dusting on light mist or tack coats lets the paint set up and bridge the contaminated spots; if that fails, the area is cleaned, or sanded, cleaned and refinished once cured.

   Ref QB-QENWENSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify fish-eyes, determine the cause (silicone contamination) and correct the conditionReport a problem with this question

6. 6. A painter is considering fish-eye eliminator for a job. Painter A says the additive removes silicone from the surface, so the wax and grease remover step can be skipped. Painter B says that once the additive is used in a coat, it must also be used in every later coat on that job. Who is right?

   • A.Neither A nor B
   • B.B only✓ Answer
   • C.Both A and B
   • D.A only

   Only Painter B is right. Fish-eye eliminator does not remove contamination; it is a silicone-type additive that lowers the paint's surface tension so it flows over the contaminated spots. Because the treated film now contains silicone, every later coat must also contain the additive or it will fish-eye. It is never a substitute for washing and wax and grease remover.

   Ref QB-8XT32PSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: fish-eyes, fish-eye eliminator principles and its drawbacksReport a problem with this question

7. 7. A vehicle arrives with a silicone tire-and-trim dressing smeared on its painted panels. Which cleaning sequence best prevents fish-eyes in the refinish?

   • A.Soap-and-water wash, then wax and grease remover before sanding and before spraying✓ Answer
   • B.Wax and grease remover wiped on and left to air-dry on the panel before tacking
   • C.A final wipe with reducer from the mixing room, since any solvent cuts silicone
   • D.Sanding first, then a single wax and grease remover wipe just before spraying

   Washing removes water-soluble dirt, and wax and grease remover used before sanding keeps the sandpaper from driving silicone into the scratches; a second cleaning before spraying removes what handling has added. The remover is wiped on wet and wiped off dry with a clean cloth, because letting it air-dry redeposits the contamination. Reducer is not a cleaning product.

   Ref QB-REZ8MPSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: fish-eyes caused by silicone contamination; I-CAR refinish training principles for surface cleaningReport a problem with this question

8. 8. All of these statements about fish-eye eliminator are true EXCEPT:

   • A.It removes silicone from the surface so later refinishes stay clean✓ Answer
   • B.It hides the contamination instead of removing it from the surface
   • C.It must be added to every later coat applied on that same job
   • D.It can carry into spray guns and cause fish-eyes on later jobs

   Fish-eye eliminator does not remove silicone; it lowers the paint's surface tension so the paint flows over the contamination, which stays on the panel. That is why it masks rather than cures the problem, must be carried into every later coat on the job, and can contaminate guns and equipment so later jobs fish-eye. Thorough cleaning is the real fix, and the additive is a last resort used per the manufacturer's directions.

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9. 9. Before refinishing an older vehicle, a painter suspects the existing finish is a lacquer or air-dry enamel that could lift under a urethane topcoat. Which check confirms whether the finish is sensitive?

   • A.Measuring total film build to see if it exceeds the paint maker's limit
   • B.Pressing on masking tape and pulling it off to see if the finish peels
   • C.Rubbing a hidden spot with lacquer thinner to see whether it softens✓ Answer
   • D.Wiping with wax and grease remover to see if color comes off on the rag

   A solvent rub test with lacquer thinner shows sensitivity directly: a lacquer or air-dry finish softens or dissolves, while a fully cured two-component finish does not. Color on a cleaning rag only shows a single-stage finish, a tape pull checks adhesion, and film build measures thickness; none of them tells whether the finish will swell under strong solvents.

   Ref QB-NEX84KSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify lifting, determine the cause and correct the condition (sealing a sensitive finish)Report a problem with this question

10. 10. Freshly sprayed urethane primer-surfacer begins to wrinkle and swell over a repaired area within minutes. Painter A says this is solvent popping and the cure is to apply the next coat wetter. Painter B says this is lifting, caused by the new coat's solvents attacking a sensitive film underneath. Who is right?

    • A.B only✓ Answer
    • B.Neither A nor B
    • C.Both A and B
    • D.A only

    Only Painter B is right. Wrinkling and swelling that appears while the coat is still wet is lifting: solvents in the new material penetrate and swell a sensitive or uncured film below it. Solvent popping is small bubbles or pinholes from solvent trapped as the film dries, and a wetter coat would push more solvent into the sensitive layer and make lifting worse.

    Ref QB-5X4T3YSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify lifting (surface distortion or wrinkling) and determine the causeReport a problem with this question

11. 11. Lifting has occurred over a sensitive air-dry enamel on a fender. Painter A says to let it dry, sand off the lifted film, seal the area with a compatible barrier sealer and refinish. Painter B says that if the lifting is severe or widespread, the finish should be stripped to a sound substrate. Who is right?

    • A.A only
    • B.Neither A nor B
    • C.B only
    • D.Both A and B✓ Answer

    Both painters are right. Lifted paint must dry fully before it can be sanded off; a compatible barrier sealer then isolates the sensitive enamel so the new solvents cannot reach it. When the lifting is severe or covers a large area, the unstable finish cannot be trusted under a sealer and is removed down to a sound substrate before refinishing.

    Ref QB-MEXMGXSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify lifting and correct the condition (incompatible undercoats, sealing a sensitive finish)Report a problem with this question

12. 12. Basecoat lifted over a two-component urethane primer-surfacer. The TDS calls for the primer to dry 1 hour before sanding and topcoating, but the painter sanded and topcoated it after 20 minutes. What is the most likely cause of the lifting?

    • A.The primer was sanded with too fine a grit for the basecoat to grip
    • B.Dry, light basecoat coats trapped air bubbles inside the primer
    • C.The primer was topcoated before it had cured as the TDS requires✓ Answer
    • D.The basecoat was sprayed with too little air pressure at the gun

    An undercoat that has not cured is still soft and solvent-sensitive, so the topcoat's solvents penetrate it and make it swell and wrinkle. Waiting the full dry time on the TDS before sanding and topcoating prevents it. Low gun pressure, sanding grit and dry coats affect texture or adhesion, but they do not make an underlying film swell.

    Ref QB-4XRFWWSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify lifting and determine the cause (uncured undercoats); paint manufacturer technical data sheet practiceReport a problem with this question

13. 13. After a door was refinished, the customer reports that the adjacent fender and the windshield feel rough and sandy, although neither was painted. What is the most likely cause?

    • A.Dirt fell on them from booth filters that were overdue for replacement
    • B.Overspray settled on them because they were not masked off from the spray✓ Answer
    • C.Industrial fallout landed on them while the car was parked outside
    • D.Dry spray formed on them because the gun air pressure was set too low

    Dry, rough paint particles on surfaces that were never sprayed are overspray, and the usual cause is that adjacent panels and glass were not masked off. Dry spray is a rough texture on the panel being painted, not on neighboring parts, and booth dirt or fallout would show as embedded specks rather than a sandy layer of paint next to the repair.

    Ref QB-KEKABWSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify an overspray condition and determine the causeReport a problem with this question

14. 14. Light overspray has dried on the cured clearcoat of a quarter panel next to a refinished door. Which correction is most appropriate?

    • A.Wipe the panel hard with lacquer thinner to dissolve the particles
    • B.Sand the panel with coarse grit and refinish it to the next edge
    • C.Wax over the panel so the particles are sealed under protection
    • D.Clay bar the panel, then polish out any roughness that remains✓ Answer

    Overspray sits on top of the cured clear, so a clay bar lifts it off without removing finish, and polishing removes any remaining roughness. Strong lacquer thinner can damage the finish, sanding and refinishing a whole panel is unnecessary for light overspray, and wax would only trap the particles on the surface.

    Ref QB-3XD5RVSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify an overspray condition and correct the condition; I-CAR refinish training principlesReport a problem with this question

15. 15. A painter is troubleshooting heavy overspray on panels next to the repair. Painter A says the gun was most likely held too close to the panel. Painter B says the gun air pressure was most likely set too low. Who is right?

    • A.B only
    • B.A only
    • C.Both A and B
    • D.Neither A nor B✓ Answer

    Neither painter is right. Holding the gun too close lays on a heavy wet film that tends to sag, and low air pressure gives coarse atomization with less bounce-back; neither throws more paint onto neighboring panels. Overspray increases when air pressure is too high, the gun is held too far away or at a poor angle, the technique is too dry, or masking is inadequate.

    Ref QB-JE8Y5VSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify an overspray condition and determine the causeReport a problem with this question

16. 16. All of these can increase overspray on adjacent panels EXCEPT:

    • A.Holding the gun farther from the panel than recommended
    • B.Using more air pressure than the TDS calls for
    • C.Leaving gaps in the masking around panel openings
    • D.Holding the gun closer to the panel than recommended✓ Answer

    Holding the gun closer than recommended puts more of the paint onto the target and builds a heavy, wet film; its typical result is sags or runs, not overspray. A gun held too far away, excess air pressure and gaps in the masking all send dry paint particles onto surfaces that were not meant to be painted.

    Ref QB-2X2TJUSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify an overspray condition, determine the cause and correct the conditionReport a problem with this question

17. 17. On a two-tone job, the painter masked over the first color soon after it flashed, sprayed the second color and force-dried the panel with the tape still on. After unmasking, the tape's outline and texture are printed into the first color. What is the most likely cause?

    • A.Using fine-line tape instead of general-purpose paper masking tape
    • B.Pulling the tape back over itself at a sharp angle during removal
    • C.Taping over the first color before it had cured enough to resist marking✓ Answer
    • D.Spraying the second color with too little air pressure at the edge

    Tape tracking happens when tape is applied over paint that is still releasing solvent and is soft; the tape and its adhesive press their pattern into the film, and heat while the tape is on makes it worse. Letting the first color cure per the TDS before masking prevents it. Fine-line tape and pulling the tape back over itself are correct practices, and gun pressure does not imprint tape texture.

    Ref QB-HEVMYTSource: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify tape tracking/marking and determine the causeReport a problem with this question

18. 18. A painter wants to prevent tape tracking on a stripe that will be masked over a freshly painted panel. Painter A says to let the first finish cure as the TDS directs before taping over it. Painter B says to use automotive refinish fine-line tape rather than general-purpose masking tape. Who is right?

    • A.Neither A nor B
    • B.Both A and B✓ Answer
    • C.A only
    • D.B only

    Both painters are right. Tape pressed onto paint that is not yet cured leaves its outline and texture in the film, so the first finish must reach the cure the TDS calls for before masking over it. Refinish-grade fine-line tape is made to release cleanly and leave a sharp edge on fresh finishes, while general-purpose tape is more likely to mark the paint or leave adhesive behind.

    Ref QB-9XH5S4Source: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify tape tracking/marking, determine the cause and correct the conditionReport a problem with this question

19. 19. Light tape tracking is visible in a fully cured clearcoat along a two-tone break line. Painter A says it can usually be wet-sanded with a fine abrasive and then polished. Painter B says to re-tape the line and spray an extra coat of clear to bury the mark. Who is right?

    • A.A only✓ Answer
    • B.B only
    • C.Both A and B
    • D.Neither A nor B

    Only Painter A is right. Minor tape tracking lies in the surface of the cured clear, so fine wet-sanding levels it and polishing restores the gloss; only severe tracking needs sanding and refinishing. Re-taping and adding clear repeats the conditions that caused the mark, builds a ridge at the tape edge and does not level the impression underneath.

    Ref QB-RECY64Source: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify tape tracking/marking and correct the conditionReport a problem with this question

20. 20. After a stripe is sprayed, removing the masking tape leaves a raised, ragged ridge of paint along the edge. Which removal technique helps prevent this?

    • A.Rolling the tape toward the fresh paint so the edge is pressed flat
    • B.Pulling the tape straight up, at a right angle to the panel surface
    • C.Pulling the tape back over itself at a sharp angle, away from the paint edge✓ Answer
    • D.Leaving it on through the bake cycle and pulling it while still hot

    Pulling the tape back over itself at a sharp angle, away from the paint, cuts the film cleanly at the tape edge, with timing set by the product instructions. Pulling straight up tears the film and lifts a ragged edge, rolling the tape into the fresh paint smears it, and leaving tape on through a bake bonds the adhesive and promotes tape marking.

    Ref QB-8Z4YK3Source: ASE Collision Repair and Refinish Study Guide, Test B2 task list: identify tape tracking/marking, determine the cause and correct the conditionReport a problem with this question

Practice questions based on the Official ASE Study Guide task list for the Painting and Refinishing (B2) test. This site is not affiliated with or endorsed by ASE, and these are not real exam questions. ASE revises its task lists periodically and sets the test length, passing standard and certification requirements, including the hands-on experience required for certification, which is separate from registering for the test. Mix ratios, flash and bake times, film builds and gun settings come from each product's own technical data sheet and are deliberately not tested here; VOC and emission rules are set federally and may be stricter in your state or air district. Confirm the current study guide and the rules that apply where you work. Official ASE B2 test page →