Discover expert tips on selecting the right sealant for marble, aluminum panels, and glass curtain walls to ensure durability and aesthetic appeal.
In previous blog posts, we learned about the principles of compatibility testing. This test is crucial for choosing sealants for different substrates. Today, we’ll discuss how to choose sealants for three common substrates: marble, aluminum panels, and curtain wall glass.
Features: It is a pure natural mineral stone, mainly composed of calcium carbonate. The base material has a porous structure and strong chemical permeability. It is necessary to avoid the migration of oils and chemicals that could contaminate the base material.
How to Choose a Sealant for Marble?
When choosing a sealant for marble, it is necessary to take into account both the application scenario and the characteristics of the substrate itself.
- Marble is not acid-resistant, so acidic adhesives should be absolutely avoided. Neutral and modified silicone sealants are the preferred choices, as these sealants do not contain acidic byproducts and are very friendly to marble.
- Marble is not oil-resistant. Small-molecule plasticizers in ordinary sealants can easily migrate to the stone, causing staining. This manifests as dust accumulating on the stone surface due to the oil-based plasticizers, making it difficult to clean and resulting in dark areas. To avoid this, the sealant needs to be adjusted to a plasticizer-free or non-migrating plasticizer formula.
If the marble is used outdoors, the sealant needs to consider UV resistance and weather resistance; for indoor environments, mildew resistance and waterproofing are important. Therefore, when choosing neutral or modified silicone sealants, it is necessary to check whether the product composition possesses these functional characteristics.
Aluminum Plate
Features: It is an aluminum alloy material mixed with other metallic elements. The substrate surface is generally treated with a special coating, resulting in a smooth surface and low surface energy. Aluminum sheets are prone to thermal expansion and contraction due to temperature changes and easily react chemically with acidic substances.
How to Choose Sealant for AluminumPlate?
Based on the characteristics of aluminum panels, when selecting sealants, we need to consider those with high displacement ability and no corrosive acetic acid components. Neutral silicone sealants and modified silicone sealants are friendly to aluminum panels and non-corrosive.
Similarly, for outdoor applications, sealants with UV resistance and weather resistance should be selected; for indoor environments, their mildew and water resistance properties need to be considered. The linear coefficient of thermal expansion of aluminum alloy is approximately 2.3 × 10⁻⁵ /°C to 2.4 × 10⁻⁵ /°C. In summer, the diurnal temperature range can reach 15-25°C. A 1-meter aluminum panel can experience approximately 0.5mm of expansion and contraction.
Before the sealant at the joints is fully cured, it faces the risk of bulging or collapsing due to the expansion and contraction of about 10% caused by the deformation of the aluminum panel, which affects both aesthetics and performance. Therefore, the formulation of weather-resistant sealants for outdoor aluminum panel curtain walls needs to be optimized to improve initial tack and accelerate deep curing.
Glass Curtain Wall
Glass curtain walls are an exterior wall structure in which insulated glass units are bonded to a metal frame. With the increasing use of insulated glass, sealant has become one of the key materials for the stability and reliability of glass curtain walls.
Glass curtain walls are subjected to multiple environmental pressures over long periods, including wind pressure, temperature differences, and ultraviolet radiation. Problems can have serious consequences; therefore, the requirements for sealant materials are extremely high, demanding strong structural integrity and weather resistance.
How to Choose Sealant for Glass Curtain Walls?
Structural sealants possess strong load-bearing, structural bonding, and tensile properties, capable of withstanding wind pressure, vibration, and temperature variations. Weather-resistant sealants offer waterproofing, UV protection, and anti-aging properties. WD-981 two-component neutral silicone structural adhesive and WD-986 one-component neutral silicone structural adhesive are two sealants that combine structural strength and weather resistance.
Their high bond strength and excellent tensile properties make them ideal for structural bonding and glass protection. These two adhesives have extensive practical experience, have received consistent praise from domestic and international customers, and have passed the Dubai Central Laboratory (DCLD) certification!
In practical applications, don’t forget to conduct compatibility and adhesion tests between the substrate and the sealant. Correct material selection, coupled with pre-application compatibility testing, will provide you with a perfect sealant application experience!
