Strut News

Polyester or Vinylester: Which Fiberglass Unistrut is right for your project?

Fiberglass Strut and Fitting

Fiberglass Unistrut is available in both polyester and vinylester resins, so how do you determine which resin is ideal for your project.  In order to design a Unistrut Fiberglass system for your application, we would consider the following factors:  Chemical Resistance, Temperature Ranges, and Loading.


  • Chemical Resistance
    • Both Polyester and Vinylester resins have their own specifications regarding its performance against corrosion resistance.  Our chemical compatibility chart should be used to determine which Fiberglass Strut material will provide the best performance in your particular application.  The results in the chart are based upon immersion for a 24 hour period.  Less severe chemical contact, from events like splashing, spills, or vapors will exceed the performance results in the table.
    • Fiberglass Unistrut Chemical Compatibility Chart
  • Temperature Ranges
    • Each Fiberglass resin has a unique range of temperatures that the resin is designed to operate within.  Polyester Unistrut is rated between -35 degrees Fahrenheit to 200 degrees Fahrenheit.  Vinylester Unistrut is rated from 35 degrees Fahrenheit to 200 degrees Fahrenheit.  The temperature ranges are to be used only as a general guideline.  Continual exposure to elevated temperatures reduces the strength properties of plastics and glass reinforced fiberglass.
    • Note: The Fiberglass connection fittings have different temperature ranges than the channel resins.  Be sure to check the fittings you are considering are Polyurethane (-40° to 140°F) or Polypropylene (-30° to 150°F).
  • Loading
    • The last factor to consider when deciding between Polyester or Vinylester resin would be loading requirements of the support.  The vinyl ester system is somewhat stronger than polyester and should be used where loading requirements are higher.  To determine which Fiberglass profile is right for your application, refer to our loading chart below:
    • Fiberglass Unistrut Loading Chart
  • For more information on Unistrut Fiberglass Channel and Fiberglass fittings, Fiberglass Unistrut
  • For technical or loading information, check out our full Fiberglass catalog here: Fiberglass Strut Catalog