Coating Knowledge Hub

Resin characteristics and applications

• Characteristics and uses of acrylic resins
• Characteristics and uses of epoxy resins
• Characteristics and uses of polyurethane resins
• Characteristics and uses of fluoropolymer resins
• Characteristics and uses of silicone resins

Understanding color and pigments

• Pigments used in paints and their functions

Balancing dissolving power and drying

• Types and characteristics of solvents
• General properties of solvents
• Characteristics of water as a solvent
• Designing solvent composition

Understanding the surface supporting the coating film

• Surface preparation of steel
• Phosphate treatment before coating
• Adhesion and causes of peeling

Considering application methods and conditions

• What is coating technology?
• Why apply paint in multiple layers?
• Basics of spray coating
• Basics of electrostatic spray coating
• Preparing a suitable coating environment
• Planning and preparing coating work
• Mixing two-component paints and pot life

Types and characteristics of powder coatings

• Types of powder coatings
• Epoxy powder coatings
• Epoxy-polyester powder coatings
• Polyester powder coatings
• Acrylic powder coatings
• Fluoropolymer powder coatings

Addressing scratches, chemicals, heat and electricity

• Scratch-resistant paints
• Chemical-resistant paints
• Heat-resistant paints
• Electrical insulating paints
• Conductive paints and electromagnetic shielding

Understanding the role of a booth

• Types of coating booths

Check the relationships between substrate, surface preparation and coating film.

• Poor Adhesion Is Not Just a Paint Problem: Assessing the Substrate, Surface Preparation, and Wettability
• Do not look only to coating materials for the causes of coating defects
• Why rust can occur even with rust-preventive coatings
• Lifting Is a Defect Caused by Topcoat Solvent Attacking the Existing Coating Film
• Do not apply repair coatings without identifying the existing coating film

Check humidity, surface temperature and thinner drying behavior.

• Investigate blushing and whitening through high humidity and thinner selection
• Hazing and chalking are signs of coating surface deterioration

Investigate film thickness, gun distance and application conditions.

• Sagging and Bubbles Arise from Excessive Film Build and Spraying Too Close
• Sagging, roughness and poor surface texture in spray coating are not just material problems
• Setting Time Causes Defects When It Is Too Short or Too Long
• Pinholes and foaming occur when solvent and gas cannot fully escape from the coating film

Check surface preparation, air and the coating environment.

• Investigate cratering, particle defects, and dirt contamination through the environment and surface preparation as well as the coating material
• Moisture and oil cause particle defects and blockages in powder coating
• Where Do Contamination and Dirt Nibs Arise in Electrodeposition Coating?
• To reduce dirt contamination defects, examine the building as well as the coating booth

Consider drying and the solvents or gases remaining within the coating film.

• Pinholes and foaming occur when solvent and gas cannot fully escape from the coating film
• Setting Time Causes Defects When It Is Too Short or Too Long
• Control air, exhaust, and solvent vapor concentration in the drying oven
• What Is Drying? The Process That Turns Paint into a Coating Film

Check substrate expansion, the existing film and the effects of the topcoat.

• Cracking Arises from Differences in Expansion and Contraction Between the Substrate and Coating Film
• Lifting Is a Defect Caused by Topcoat Solvent Attacking the Existing Coating Film
• Do not apply repair coatings without identifying the existing coating film
• Why does cracking occur in plastic coatings?
• Cracking in Wood Coatings Is Not Just a Paint Problem

Distinguish drying from curing and check time and workpiece temperature.

• Paints That Dry and Paints That Harden by Reaction: The Difference Between Drying and Curing
• What Is Drying? The Process That Turns Paint into a Coating Film
• Dry to the Touch Is Not the Same as Ready to Ship
• In Bake Drying, Check Workpiece Temperature Rather Than Oven Temperature Alone
• Re-softening is a defect in which a dried coating film becomes tacky again
• Check the Temperature Reached by the Workpiece, Not Just the Oven Setting

Investigate lighting, film thickness, mixing and application conditions.

• Color Mismatch Is Not Just a Paint Problem: Color Management Through Light, the Coating Film, and the Viewing Environment
• Break down “the color is different” — Coating quality through hue, lightness, chroma and gloss
• Control Color Differences by Defined Tolerances, Not Intuition
• Accepted at the factory, rejected at the customer's site—why color changes with the light source
• Insufficient Stirring and Inadequate Color-Change Cleaning Cause Uneven Color
• Consider Gloss Defects Through the Underlying Surface, Film Thickness, and Drying Conditions as Well as Paint
• Spray air pressure and spray distance change gloss
• Metallic Mottling Results from Poor Metallic Pigment Orientation
• Yellowing and Fading Cannot Be Judged by Initial Color Alone

Check the substrate, surface preparation and service environment.

• Coating materials alone cannot prevent rust on coated metal
• Reading the Cause from the Pattern of Rust
• Why rust can occur even with rust-preventive coatings
• Building Materials Can Rust During Post-Coating Storage—Precautions Against Rain Exposure, Foundation Moisture, and Salt Damage
• Coating Steel Structures Is Corrosion-Protection Design for Safety: The Basics of Zinc-Rich Paint, MIO, and Long-Term Maintenance
• Do not judge corrosion-protection coating by initial price alone: Recoating intervals and life-cycle cost

Check airflow, compressed air, circulating water and maintenance condition.

• Coating-Equipment Problems Extend Beyond Mechanical Failure: The Basics of Equipment Management for Quality, Safety, the Environment, and Productivity
• Preventive Maintenance to Keep the Coating Line Running—Checking Compressors, Pumps, and Fans
• Do Not Select Booth Fans by Air Volume Alone
• Is Extraction Effective at the Working Position?—The Basics of Checking Coating Booth Airflow
• Coating Booth Odors Cannot Be Solved by Exhaust Alone
• Sludge Management Is Fundamental to Odor Control in Wet Booths
• Compressed Air Systems Determine Coating Quality
• The Basics of Booth Circulation-Water and Paint-Sludge Control