Orange Peel Effect in Intumescent Paint

Orange peel effect: A challenge when using puffy paint
Entrance cladding provides critical fire protection for steel structures. However, achieving the desired aesthetic look can be complicated, especially when thick layers are required for fire estimates of more than sixty minutes. A common problem is the “orange peel” effect, which is a finish that detracts from the overall look.

Orange Peel Effect in Intumescent Paint

Orange peel effect: A challenge when using puffy paint
Entrance cladding provides critical fire protection for steel structures. However, achieving the desired aesthetic look can be complicated, especially when thick layers are required for fire estimates of more than sixty minutes. A common problem is the “orange peel” effect, which is a finish that detracts from the overall look.

Understand the effect of orange peel
The orange peel effect occurs when the top layer of paint dries faster than the undersides, causing an uneven surface. The factors that affect this issue are:

Thick Dry Film Thickness (DFT): Thick coatings, often necessary for long-term fire protection, increaseing the likelihood of orange peel.
Environmental Conditions: High temperature, low humidity and winds accelerate the drying process and exacerbate the problem.
Application methods: Unequal access to the steel surface and inconsistent application techniques contribute to the problem.
Paint Type: Water-based puffy paints tend to dry faster than solvent-based paints, which can result in a more noticeable orange peel effect.
Impact on Aesthetics
Although less noticeable from a distance, the orange peel effect becomes more noticeable upon closer inspection or when using top coat. This can greatly affect the aesthetic appearance of the steel structure.

How tot Reduce the orange peel effect.
There are several strategies that can help reduce the orange peel effect:

Improving fire resistance rating: If possible, specifying a lower fire resistance rating can reduce the required DFT and improve the aesthetic appearance.
Consider a section of steel: Small sections of steel can be equally difficult to paint. This should be considered in the design and application process.
Phased application: Applying paint in thin coats with adequate curing time between coats can help reduce the orange peel effect.
Expert Application: Hiring experienced contractors with experience using penetrating coatings is critical to achieving optimal results.
Aesthetic Finish Specification: Clearly specifying the required aesthetic finish in the project specification ensures that it is considered during procurement and implementation.
Off-field weighing: While this may be more difficult due to handling and transportation risks, off-field application can provide better control of environmental conditions and application quality.