A Guide to Choosing A Silicone Sealant Adhesive - Gluegun.com

09 Jun.,2025

 

A Guide to Choosing A Silicone Sealant Adhesive - Gluegun.com

In the silicone and sealant world there are a lot of competitors. Products with similar labels, almost identical, can often act in very different ways.  Here are some things to consider when picking your next silicone or sealant.  

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Make sure your silicone is VOC compliant.  This is a fancy way of saying there are no solvents or isocyanates in the silicone…in other words it is nature friendly.  

Choosing A Silicone Sealant

Do your research and make sure the formula is pure, and that the supplier is reputable.  It is easy to put “100% Silicone” on a label, often this is not the case.  Additives are used to dilute the formula, manipulate the properties, or alter the immediate value of a product.  When this happens inaccurately, or at the expense of the customer, formulas can become brittle after curing, they can yellow in color, they can delay the cure time to three or even four days, and they will always underperform when compared to a pure or professionally mixed formula.  You know you are using an inferior product when:

  • The product takes 3-4 to cure
  • When cured, it becomes hard and brittle
  • In the cold, it becomes thick and difficult to extrude
  • In the heat, it becomes runny and slumps
  • Smells and is corrosive

Adding compounds to formulas isn’t always a bad thing!  But it has to be left to the experts.  When it is appropriate, chemists will add compounds to formulas to increase their adhesion properties, paint ability, or even extend their use life.  Most commonly, these products are used when painting is needed.  In this case our modified polyurethane is often used because this hybrid material combines technology to produce a material with many of the same characteristics of silicones and polyurethanes but with better performing characteristics and paint ability.  

So here is your cheat sheet.

For everyday use, our 502 High Performance 100% Silicone is ideal.  Features:

  • NSF and UL Approved
  • Excellent Adhesion
  • Mold and Mildew Resistant
  • Withstands high heat and low colds

When you need a little “bite”, we recommend our 504 Commercial Grade Silicone

  • High Modules Silicone Sealant
  • Excellent Adhesion
  • Meets ASTM-C-920-86 Requirements
  • Excellent Tensile Strength

For your windows it is CLEAR that you need our 335 Silicone

  • Superior adhesion to vinyl and aluminum
  • Adheres to porous surfaces, unlike some 100% silicones
  • Resistant to corroding and yellowing
  • Resistant to weathering
  • Ideal for tight spaces, no objectionable odors are emitted
  • American Architectural and Manufacturers Association approved

How to choose silicone sealant for different construction parts?

Silicone sealant is a kind of polydimethylsiloxane as the main raw material, which can be easily extruded and used under most temperature conditions, and cured with moisture in the air to form an excellent, durable, high-modulus, high-elastic silicone sealant. Ketone rubber.

Silicone sealants can be divided into one-component, two-component, structural adhesives, weather-resistant adhesives, etc. Different silicone sealants should be selected for different construction parts:

1. Structural assembly parts.

The sealant used between the curtain wall panel and its supporting structure needs to bear a variety of loads and ensure long-term adhesion without falling off. It must meet the requirements of the national mandatory standard "Silicon Structural Sealant for Buildings" (GB) .

Link to BGP

Especially in high-rise and super-high-rise curtain walls, large-panel glass curtain walls, curtain walls using laminated insulating glass, curtain walls in earthquake-resistant 9-degree fortification areas, and even in the combination of these situations, it is even more necessary to use silicone structures with high performance. sealant. Because the adhesive has high tensile strength and elongation at break, it can withstand larger loads with the same bond width.

2. The seams of building curtain walls.

The expansion joint between the building curtain wall panel and the panel needs to be filled with glue, and silicone weather-resistant sealant should be used at this time. Because this kind of environmental silicone sealant needs to bear the displacement caused by wind load, dynamic load, and deformation caused by thermal expansion and contraction of the base material, the cohesiveness will not be damaged under tension or compression, and it is also relatively Good elastic recovery rate, after the displacement of the panel disappears, it can return to its original shape.

3. Stone panel parts.

Stone panel components must use a special stone silicone sealant. Because stone itself is a porous material, it is easily polluted and difficult to remove after contamination. General sealants contain non-reactive low-molecular substances such as plasticizers, which will migrate from the interior of the glue to the interior of the stone, and oil stains will appear on the surface of the stone and dust will be collected, causing stone pollution.

4. The top position of lighting.

Due to its own weight load, snow load, wind load, asymmetrical load, and material thermal expansion and contraction, the displacement of the daylighting roof is large and complex, not only horizontal displacement, but also shear displacement. Especially when polycarbonate board is used, due to its high coefficient of thermal expansion and contraction, it is six or seven times that of glass.

This requires the sealant to have low modulus, high displacement capacity, good material properties, and free expansion and contraction. It is best to use 50LM (50 low modulus level) silicone sealant, with a displacement capacity of plus or minus 50%. %. In addition, the glue used for the lighting roof also requires good transparency and elegant appearance.

5. The part between doors and windows.

The gap between the aluminum alloy and the glass of colored aluminum alloy doors and windows should be filled with special glue for aluminum alloy doors and windows. After fully cured, the glass can form an integral body with the aluminum alloy.

In the past, aluminum alloy doors and windows were often filled with polyacrylate, neoprene, polyurethane, etc., or the bond was easily damaged after being subjected to external force, or harmful gases were volatilized. There are no such disadvantages when using special glue for aluminum alloy doors and windows, and it can play a long-term sealing and waterproof role.

Contact us to discuss your requirements of two component silicone sealant. Our experienced sales team can help you identify the options that best suit your needs.