Course Overview
Providing trainees with knowledge and skills to properly prepare steel surfaces and apply protective coatings
Course Duration
16–24 hours (theory + practical)
Target Audience
Painters, technicians, inspectors, maintenance personnel, and supervisors in construction, fabrication, industrial, and marine sectors.
Learning Objectives
By the end of this course, participants will be able to:
Understand corrosion mechanisms on steel
Identify different surface contaminants and cleaning methods
Perform surface preparation using mechanical, abrasive blasting, and chemical processes
Select appropriate coating systems based on service conditions
Apply primers, intermediate coats, and topcoats correctly
Perform quality checks such as DFT, adhesion, profile measurements
Ensure safe handling of materials and equipment
Course Modules
Module 1: Introduction to Corrosion & Coating Systems
Topics Covered:
- Why steel corrodes (oxidation, environment, galvanic action)
- Types of corrosion: Surface rust, Pitting, Crevice corrosion, Under-film corrosion
- Purpose of protective coatings
- Types of coating systems: Primers, Intermediate coats, Topcoats
- Coating selection factors: environment, service life, temperature, chemicals
Learning Activities:
Corrosion sample observation and coating failure identification
Module 2: Surface Contaminants and Cleaning Requirements
Common Contaminants:
- Mill scale
- Rust
- Oil and grease
- Dust and salts
- Old paint
- Moisture
Standards:
- ISO 8501–1 (visual cleanliness)
- ISO 8502–3 (dust)
- ISO 8503 (surface profile)
- SSPC / NACE surface prep standards
Module 3: Methods of Surface Preparation
3.1 Cleaning Methods
- Solvent Cleaning (SSPC SP 1): Removal of oil, grease, tar using mineral spirits and degreasers
- Water Jetting: Low/high-pressure washing to remove salts and dirt
3.2 Hand and Power Tool Cleaning
- Hand Tool Cleaning (SSPC SP 2): Scrapers, wire brushes, sandpaper
- Power Tool Cleaning (SSPC SP 3): Grinders, needle scalers, power wire brushes
- Power Tool to Bare Metal (SSPC SP 11): Minimum 25 μm profile requirement
3.3 Abrasive Blasting
Used when high-quality surface preparation is required. Methods include dry, wet, and vacuum blasting.
Surface Cleanliness Grades (ISO 8501-1):
- Sa 1 – Light blast cleaning
- Sa 2 – Thorough cleaning
- Sa 2.5 – Very thorough cleaning (most commonly required)
- Sa 3 – Blast to "white metal"
Abrasive Materials:
Steel grit/shot, Garnet, Aluminum oxide, Glass bead
Surface Profile Measurement:
Using replica tape and surface profile gauge. Target profile: 40–100 µm
Module 4: Paint and Coating Application
Types of Paint Application:
Brush, Roller, Air spray, Airless spray
Environmental Conditions:
- Steel temperature: ≥ 3°C above dew point
- Humidity: < 85%
- No painting on wet or contaminated surfaces
Application of Coating System:
- Primer application: Zinc-rich epoxy primer for corrosion resistance
- Intermediate coat: Build up dry film thickness
- Topcoat: UV protection, aesthetic finish
Dry Film Thickness (DFT):
Measured with electronic DFT gauge (typically 50–300 μm total)
Module 5: Inspection & Quality Control
Inspection Steps:
- Pre-surface prep inspection
- Visual cleanliness check
- Surface profile measurement
- Salt contamination testing
- Paint mixing and batch checking
- Wet Film Thickness (WFT) check
- Dry Film Thickness (DFT) measurement
- Adhesion testing
- Holiday (pin-hole) testing
Inspection Tools:
- Surface profile gauge
- DFT meter
- Hygrometer
- Psychrometer
- Wet film comb gauge
- Borescope (as required)
Module 6: Safety in Surface Preparation & Painting
Hazards:
- Dust and airborne particles
- Noise from power tools and blasting
- Respiratory hazards (solvents, paint fumes)
- Flammable materials
- High-pressure spray hazards
Required PPE:
- Respirators (half-mask or full-face)
- Safety goggles
- Coveralls and gloves
- Hearing protection
- Safety shoes
- Blast helmet (for abrasive blasting)
Safe Work Practices:
Proper ventilation, explosion-proof equipment, grounding and bonding of spray equipment, safe handling of solvents, emergency response procedures.
Module 7: Common Defects and Troubleshooting
Coating Defects:
•Runs and sags
•Pinholes
•Blistering
•Peeling
•Cracking
•Under-film corrosion
•Dry spray
•Mud cracking
Causes & Remedies:
- • Incorrect mixing → ensure proper ratios
- • Poor surface prep → reblast or clean
- • Wrong environmental conditions → monitor dew point and humidity
- • Incorrect spray technique → adjust pressure/nozzle size
Practical Training Activities
- Demonstration of hand and power tool cleaning
- Abrasive blasting exercise
- Mixing and applying primer, intermediate, and topcoat
- DFT measurement practice
- Safety drill (respirator fit test, ventilation)
Assessment & Certification
- Theory Exam: Multiple choice and short answer questions
- Practical Evaluation: Demonstration of surface prep, painting, and inspection
- Completion Certificate awarded if trainee meets competency requirements