350 QUESTIONS AND ANSWERS
1. Q: What is the primary purpose of surface preparation before coating
application? ANSWER To remove contaminants, create proper surface
profile, and ensure maximum adhesion between the coating and substrate.
2. Q: What does SSPC-SP1 specify? ANSWER Solvent cleaning to remove
oil, grease, dirt, soil, salts, and contaminants, but not rust, mill scale, or paint.
3. Q: What is the difference between SSPC-SP2 and SSPC-SP3? ANSWER
SP2 is hand tool cleaning, SP3 is power tool cleaning. SP3 achieves better
surface preparation than SP2.
4. Q: What does SSPC-SP10 specify? ANSWER Near-White Metal Blast
Cleaning - removal of all visible oil, grease, dirt, rust, paint, oxides, corrosion
products, and foreign matter.
5. Q: What is the minimum surface profile for most protective coatings?
ANSWER 1-3 mils (25-75 microns), depending on coating specifications.
6. Q: What tool is used to measure surface profile? ANSWER Surface profile
gauge, replica tape, or stylus-type profilometer.
7. Q: What is flash rusting? ANSWER The formation of rust on a freshly
cleaned steel surface due to moisture exposure before coating application.
8. Q: How can flash rusting be prevented? ANSWER Control humidity, use
dehumidifiers, apply primer immediately after cleaning, or use flash rust
inhibitors.
9. Q: What is the purpose of anchor pattern? ANSWER To provide
mechanical adhesion for the coating by creating surface roughness.
10. Q: What does SSPC-SP6 specify? ANSWER Commercial blast cleaning -
removal of all oil, grease, dirt, rust scale, and foreign matter except for slight
shadows, streaks, or discolorations.
,11. Q: What is mill scale? ANSWER A layer of iron oxides formed during hot
rolling of steel that must be removed before coating.
12. Q: What is the difference between dry and wet abrasive blasting?
ANSWER Dry uses abrasive media alone; wet adds water to reduce dust and
heat, and can include inhibitors.
13. Q: What is the purpose of dust removal after blasting? ANSWER To
remove all abrasive residue and dust that could interfere with coating adhesion.
14. Q: What is the maximum time between surface preparation and primer
application? ANSWER Usually 4-8 hours in normal conditions, but varies
with humidity and specifications.
15. Q: What does SSPC-SP5 specify? ANSWER White Metal Blast Cleaning
- complete removal of all visible oil, grease, dirt, rust, paint, oxides, and foreign
matter.
16. Q: What is the purpose of surface contamination testing? ANSWER To
detect chlorides, oils, or other contaminants that could cause coating failure.
17. Q: What is the acceptable chloride level on steel surfaces? ANSWER
Typically less than 7 mg/m² (ISO 8502-6) or 3 mg/m² for critical applications.
18. Q: What is power tool cleaning? ANSWER Mechanical cleaning using
powered tools like grinders, sanders, or wire brushes to remove loose material.
19. Q: What abrasive media is commonly used for blast cleaning? ANSWER
Steel grit, steel shot, aluminum oxide, garnet, copper slag, or glass beads.
20. Q: What is spent abrasive? ANSWER Used blasting media that has lost its
cutting ability and contains contaminants from the cleaned surface.
21. Q: What is the purpose of compressed air testing? ANSWER To ensure
compressed air used for cleaning is free of oil, water, and other contaminants.
22. Q: What is water jetting? ANSWER High-pressure water cleaning method
used to remove coatings, contaminants, and prepare surfaces.
23. Q: What pressure levels are used in high-pressure water jetting? ANSWER
10,000-40,000+ PSI (700-2,800+ bar) depending on application requirements.
24. Q: What is the advantage of vacuum blasting? ANSWER Contains
abrasive and debris, reducing environmental contamination and worker
exposure.
, 25. Q: What is pickling? ANSWER Chemical cleaning process using acids to
remove rust, scale, and oxides from metal surfaces.
26. Q: What is flame cleaning? ANSWER Surface preparation method using
oxy-fuel flame to remove mill scale and rust, followed by wire brushing.
27. Q: What is mechanical cleaning? ANSWER Surface preparation using
mechanical tools without abrasives, such as scrapers, chisels, or wire brushes.
28. Q: What is the purpose of holiday detection in surface preparation?
ANSWER To identify areas missed during cleaning that require additional
preparation.
29. Q: What is surface preparation grade Sa 2½? ANSWER ISO equivalent to
SSPC-SP10 Near-White Metal Blast Cleaning.
30. Q: What factors affect surface preparation selection? ANSWER Substrate
condition, coating requirements, environmental conditions, accessibility, and
cost.
31. Q: What is the difference between open and closed circuit blasting?
ANSWER Open circuit discards used abrasive; closed circuit recycles and
cleans abrasive for reuse.
32. Q: What safety equipment is required for abrasive blasting? ANSWER
Supplied-air respirator, protective clothing, blast helmet, hearing protection, and
safety harness if elevated.
33. Q: What is containment in blasting operations? ANSWER Enclosing the
blast area to control abrasive, dust, and debris dispersion.
34. Q: What is the purpose of surface profile measurement? ANSWER To
verify that the surface roughness meets coating specification requirements.
35. Q: What causes profile variation in blast cleaning? ANSWER Abrasive
type and size, blast pressure, angle, distance, and traverse speed.
36. Q: What is brush-off blast cleaning? ANSWER Light blasting to remove
loose rust, paint, and foreign matter while leaving tightly adherent material.
37. Q: What environmental conditions affect surface preparation? ANSWER
Temperature, humidity, wind, precipitation, and air quality.
38. Q: What is the purpose of surface preparation standards? ANSWER To
provide consistent methods and acceptance criteria for surface cleaning.
1. Q: What is the primary purpose of surface preparation before coating
application? ANSWER To remove contaminants, create proper surface
profile, and ensure maximum adhesion between the coating and substrate.
2. Q: What does SSPC-SP1 specify? ANSWER Solvent cleaning to remove
oil, grease, dirt, soil, salts, and contaminants, but not rust, mill scale, or paint.
3. Q: What is the difference between SSPC-SP2 and SSPC-SP3? ANSWER
SP2 is hand tool cleaning, SP3 is power tool cleaning. SP3 achieves better
surface preparation than SP2.
4. Q: What does SSPC-SP10 specify? ANSWER Near-White Metal Blast
Cleaning - removal of all visible oil, grease, dirt, rust, paint, oxides, corrosion
products, and foreign matter.
5. Q: What is the minimum surface profile for most protective coatings?
ANSWER 1-3 mils (25-75 microns), depending on coating specifications.
6. Q: What tool is used to measure surface profile? ANSWER Surface profile
gauge, replica tape, or stylus-type profilometer.
7. Q: What is flash rusting? ANSWER The formation of rust on a freshly
cleaned steel surface due to moisture exposure before coating application.
8. Q: How can flash rusting be prevented? ANSWER Control humidity, use
dehumidifiers, apply primer immediately after cleaning, or use flash rust
inhibitors.
9. Q: What is the purpose of anchor pattern? ANSWER To provide
mechanical adhesion for the coating by creating surface roughness.
10. Q: What does SSPC-SP6 specify? ANSWER Commercial blast cleaning -
removal of all oil, grease, dirt, rust scale, and foreign matter except for slight
shadows, streaks, or discolorations.
,11. Q: What is mill scale? ANSWER A layer of iron oxides formed during hot
rolling of steel that must be removed before coating.
12. Q: What is the difference between dry and wet abrasive blasting?
ANSWER Dry uses abrasive media alone; wet adds water to reduce dust and
heat, and can include inhibitors.
13. Q: What is the purpose of dust removal after blasting? ANSWER To
remove all abrasive residue and dust that could interfere with coating adhesion.
14. Q: What is the maximum time between surface preparation and primer
application? ANSWER Usually 4-8 hours in normal conditions, but varies
with humidity and specifications.
15. Q: What does SSPC-SP5 specify? ANSWER White Metal Blast Cleaning
- complete removal of all visible oil, grease, dirt, rust, paint, oxides, and foreign
matter.
16. Q: What is the purpose of surface contamination testing? ANSWER To
detect chlorides, oils, or other contaminants that could cause coating failure.
17. Q: What is the acceptable chloride level on steel surfaces? ANSWER
Typically less than 7 mg/m² (ISO 8502-6) or 3 mg/m² for critical applications.
18. Q: What is power tool cleaning? ANSWER Mechanical cleaning using
powered tools like grinders, sanders, or wire brushes to remove loose material.
19. Q: What abrasive media is commonly used for blast cleaning? ANSWER
Steel grit, steel shot, aluminum oxide, garnet, copper slag, or glass beads.
20. Q: What is spent abrasive? ANSWER Used blasting media that has lost its
cutting ability and contains contaminants from the cleaned surface.
21. Q: What is the purpose of compressed air testing? ANSWER To ensure
compressed air used for cleaning is free of oil, water, and other contaminants.
22. Q: What is water jetting? ANSWER High-pressure water cleaning method
used to remove coatings, contaminants, and prepare surfaces.
23. Q: What pressure levels are used in high-pressure water jetting? ANSWER
10,000-40,000+ PSI (700-2,800+ bar) depending on application requirements.
24. Q: What is the advantage of vacuum blasting? ANSWER Contains
abrasive and debris, reducing environmental contamination and worker
exposure.
, 25. Q: What is pickling? ANSWER Chemical cleaning process using acids to
remove rust, scale, and oxides from metal surfaces.
26. Q: What is flame cleaning? ANSWER Surface preparation method using
oxy-fuel flame to remove mill scale and rust, followed by wire brushing.
27. Q: What is mechanical cleaning? ANSWER Surface preparation using
mechanical tools without abrasives, such as scrapers, chisels, or wire brushes.
28. Q: What is the purpose of holiday detection in surface preparation?
ANSWER To identify areas missed during cleaning that require additional
preparation.
29. Q: What is surface preparation grade Sa 2½? ANSWER ISO equivalent to
SSPC-SP10 Near-White Metal Blast Cleaning.
30. Q: What factors affect surface preparation selection? ANSWER Substrate
condition, coating requirements, environmental conditions, accessibility, and
cost.
31. Q: What is the difference between open and closed circuit blasting?
ANSWER Open circuit discards used abrasive; closed circuit recycles and
cleans abrasive for reuse.
32. Q: What safety equipment is required for abrasive blasting? ANSWER
Supplied-air respirator, protective clothing, blast helmet, hearing protection, and
safety harness if elevated.
33. Q: What is containment in blasting operations? ANSWER Enclosing the
blast area to control abrasive, dust, and debris dispersion.
34. Q: What is the purpose of surface profile measurement? ANSWER To
verify that the surface roughness meets coating specification requirements.
35. Q: What causes profile variation in blast cleaning? ANSWER Abrasive
type and size, blast pressure, angle, distance, and traverse speed.
36. Q: What is brush-off blast cleaning? ANSWER Light blasting to remove
loose rust, paint, and foreign matter while leaving tightly adherent material.
37. Q: What environmental conditions affect surface preparation? ANSWER
Temperature, humidity, wind, precipitation, and air quality.
38. Q: What is the purpose of surface preparation standards? ANSWER To
provide consistent methods and acceptance criteria for surface cleaning.
