How to choose a silicone sealant

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.  

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

When color matters, call and ask.  We love colors, and we have a vast color portfolio! Almost all of our silicones and sealants can be custom tailored to your color needs. Visit the Silicone Section to shop all of our great silicone products as well as glue guns for dispensing silicone

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