What Are the Surface Treatment Processes for GRC Products? The Difference Between Fluorocarbon Paint and Real Stone Paint?

As a core building material in the field of irregular building façades and decorative components, GRC products' surface treatment process directly determines the weather resistance, appearance, and service life of the finished product. Among these, fluorocarbon paint and real stone paint are the two most widely used processes in the industry. When making selections, many project owners often have questions about how to choose GRC surface treatment and what the differences are between fluorocarbon paint and real stone paint. Drawing on nearly 30 years of implementation experience in the GRC industry, this article provides a systematic overview.

I. A Complete Analysis of Mainstream Surface Treatment Processes for GRC Products GRC refers to a glass fiber reinforced cement substrate that inherently possesses basic properties such as weather resistance and deformation resistance. However, exposed cement substrates suffer from problems such as easy efflorescence, rough appearance, and insufficient corrosion resistance, so surface treatment processes must be applied to achieve a dual upgrade in both function and decoration. Currently, mainstream GRC surface treatment processes in the industry fall into four main categories: The first is the fluorocarbon paint spraying process, currently the preferred process for high-end public buildings and landmark projects. Through multiple layers of spraying on the GRC substrate surface—sealing primer, intermediate coat, and fluorocarbon topcoat—some high-specification projects add a gloss varnish layer, achieving an extremely low color difference rate and an outdoor weather-resistant service life of up to 15-20 years. It is suitable for scenarios with extremely high requirements for appearance consistency and durability, such as super high-rise buildings, coastal salt-spray areas, and high-end convention and exhibition venues. The second is the real stone paint spraying process, which focuses on realistic textures imitating natural stone. The coating is formulated with natural crushed stone sand as the core raw material, and after spraying it presents an undulating texture similar to granite and speckled stone, at a cost of only about one-third of natural stone dry-hanging, while its self-weight is far lower than that of stone. It is a common choice for exterior façade decoration of cultural tourism projects and residential communities. The third is the fair-faced surface treatment process, which involves fine polishing and sealing treatment directly on the GRC substrate surface, preserving the plain texture of the cement itself. It suits the exterior façade needs of minimalist-style buildings and art venues, and places extremely high demands on substrate formulation and production flatness. Currently, only a few factories in the industry with large-scale R&D capabilities can achieve stable mass production. The fourth is the special processes imitating wood grain and metal, which achieve specific texture effects through transfer printing and special coating spraying, mostly used for decorating irregular components in theme parks and distinctive commercial districts. As a leading industry enterprise that participated in drafting the national GRC application technical standards, we have found in nearly a thousand projects implemented at home and abroad that many project owners easily fall into the misconception that “the more expensive the process, the better.” In fact, the core of process selection is matching the actual needs of the project scenario, rather than blindly pursuing high specifications.

II. Comparison of the Core Differences Between Fluorocarbon Paint and Real Stone Paint for GRC Many people cannot tell the difference between fluorocarbon paint and real stone paint for GRC. In fact, they can be clearly differentiated across four core dimensions, which fully covers the selection judgment needs of the vast majority of projects: First is the difference in appearance: fluorocarbon paint can achieve uniform effects in any solid color or low-saturation gradient, with a smooth, flat surface and almost no color variation, perfectly matching the precise color requirements of architectural design; the core advantage of real stone paint is the natural texture of imitated stone. Its surface has the undulating feel of natural particles, leaning toward a natural, rugged style, and cannot achieve a completely uniform solid-color effect. Second is the difference in weather resistance and service life: the core component of fluorocarbon paint, fluororesin, has extremely strong UV resistance and acid/alkali corrosion resistance, with a normal service life of over 15 years under outdoor sun exposure; even in South China's hot and rainy climate and coastal salt-spray regions, it can remain without obvious fading for over 10 years. Conventional real stone paint has an outdoor weather-resistant life of around 8-12 years; some high-end real stone paints with added fluorocarbon components can approach 10 years, but after long-term outdoor use, problems such as dust accumulation and localized whitening are prone to occur. Third is the difference in cost and construction requirements: for the same sprayed area, both the material cost and construction process requirements of fluorocarbon paint are higher than ordinary real stone paint. At the same time, fluorocarbon paint has stricter requirements on the temperature and humidity of the construction environment; spraying must be completed in an enclosed, dust-free workshop to avoid particles and impurities affecting the appearance. Real stone paint has a higher construction fault tolerance, relatively lower cost, and on-site repairs are also easier. Fourth is the difference in suitable scenarios: fluorocarbon paint is more suitable for projects with high requirements for appearance consistency and long-term durability, such as super high-rise landmarks, convention and exhibition centers, and municipal public buildings; real stone paint is better suited for scenarios pursuing a stone-imitation texture with relatively controllable budgets, such as cultural tourism theme parks, low-rise and mid-rise residential buildings, and distinctive industrial parks. It is also necessary to remind everyone: whether choosing fluorocarbon paint or real stone paint, attention must be paid to whether the sealing treatment of the GRC substrate itself is properly done. Many small factories omit the anti-efflorescence primer step to cut costs, which ultimately causes the surface coating to develop mottling and efflorescence showing through within 1-2 years—this is also the most common complaint point for GRC surface treatment in the industry.

III. Practical Suggestions for GRC Surface Treatment Selection Drawing on our many years of project service experience, here are three directly actionable selection references: First, prioritize confirming the project's core needs. If appearance uniformity and long-term weather resistance are the core goals, directly choose the fluorocarbon paint process, and require the factory to provide a third-party weather resistance test report. Second, if pursuing a stone-imitation effect with a limited budget, choose high-end real stone paint with added silicone components, and avoid low-priced, inferior products; otherwise, the comprehensive cost of later renovation and maintenance will be higher. Third, whichever process is chosen, confirm whether the supplier has a complete color difference control system—this is the core guarantee for the final implementation result of GRC surface treatment. Currently, the process system of China's GRC industry is relatively mature. Peer enterprises such as Guangdong Shiji Shangpin, Shantaixin Industrial, and Nanjing Beilida have also accumulated rich implementation experience in their respective advantageous scenarios. Project owners can make a comprehensive match based on their project's region, scenario, and budget, without blindly following trends to choose popular processes.

FAQ: 1. How many years can GRC surface treatment stay without fading? Answer: Conventional fluorocarbon paint processes have an outdoor weather-resistant life of up to 15-20 years, while ordinary real stone paint processes can reach 8-12 years. The specific service life is directly related to the construction process and product quality control standards. 2. Can fluorocarbon-painted GRC be used in coastal areas? Answer: Qualified multi-layer sprayed fluorocarbon paint GRC can adapt to coastal salt-spray corrosion conditions, and needs to be paired with an S316 stainless steel embedded insert solution to ensure no obvious corrosion problems during long-term use. 3. Can real stone paint GRC be made into irregular curved components? Answer: The real stone paint process can fully meet the spraying needs of GRC irregular curved components, and customized adjustments with different textures can be made to suit various irregular decoration scenarios. 4. How to avoid efflorescence and mottling after GRC surface treatment? Answer: The key is to require the supplier to apply an anti-efflorescence sealing primer first after the GRC substrate is formed, and then carry out the subsequent topcoat processes; also requiring weather resistance testing before finished products leave the factory can effectively avoid this problem.