Coating Systems More than one coat. One complete protection system.
A coating system is not simply a selection of paint products. Primer, intermediate and topcoat each do a different job — and the number of coats and the film thickness are specified, not guessed.
A coating system is not simply a selection of paint products.
Each layer has a purpose, and the complete system is designed around the substrate, environment, required durability and performance.
01Primer, intermediate coat & topcoatWhat’s the difference?
A multi-layer coating system is designed so that different layers perform different functions.
Why use different layers?
Because one coating layer may not be designed to provide every required function.
Primer protects the foundation. Intermediate builds protection. Topcoat protects the system.
02What is a coating system?One system. Multiple functions.
A coating system is the complete combination of surface preparation and coating layers selected to protect a particular substrate in a particular environment.
A typical protective system may consist of:
The exact system can vary depending on:
- Substrate
- Corrosivity of the environment
- Required service life
- Chemical or weather exposure
- Application method
- Appearance requirements
- Project specification
Why does it matter?
Choosing individual products without considering how they work together can lead to compatibility or performance problems.
Don’t choose a paint. Choose a complete protection system.
03How do you choose the right coating system?Start with the environment — not the colour.
There is no single coating system suitable for every application. Before selecting a system, consider:
What are we protecting?
Steel, concrete, aluminium or another substrate?
Where is it located?
Indoor, outdoor, coastal, marine or industrial?
What will it be exposed to?
Moisture, salt, chemicals, UV, abrasion, temperature or immersion?
How long should it last?
The required durability and maintenance expectations influence the system selection.
How will it be applied?
Application method and site conditions can affect product and system suitability.
What finish is required?
Colour, gloss, texture and appearance may also influence the topcoat selection.
The right coating system is the one designed around the asset and the environment.
04How many coats of paint are required?There is no universal number.
The number of coats depends on the specified coating system, required dry film thickness, substrate condition, application method and performance requirements.
A system may consist of:
Is more always better?
No. Applying excessive coating thickness can create its own problems, including curing issues, cracking, solvent entrapment or other defects depending on the coating type.
The number of coats should therefore follow the specified coating system and manufacturer’s requirements, rather than simply applying more paint for extra protection.
It’s not about how many coats. It’s about achieving the right system and thickness.
05Why is coating thickness important?The right thickness matters.
Coating thickness is an important part of coating performance.
Too little coating may not provide the required protection or durability.
Too much coating can also create problems such as cracking, poor curing, solvent entrapment or other application defects, depending on the coating system.
What is DFT?
DFT means Dry Film Thickness — the thickness of the coating after it has dried or cured. The required DFT is normally specified for the coating system and should be achieved consistently across the coated surface.
How is it checked?
DFT can be measured using appropriate coating thickness gauges, with the inspection method depending on the substrate and project requirements.
Why does it matter?
Correct coating thickness helps ensure that the coating system can deliver its intended level of protection and service performance.
The goal is not the thickest coating. It is the correct coating thickness.
UNF insightDesign the system. Don’t just apply the paint.
A successful coating system brings together:
At UNF, we look beyond the individual product to understand the complete coating requirement — from substrate and environment to application and expected performance.
Protecting What Matters. Built to Last.