Fibre Glast Shopping Cart Image
McAfee Secure sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams
Products Category Text

Polyester Resins

Polyester Resins are the most widely used resins in the composites industry. Polyester Resins are less expensive, offer some corrosion resistance, and are more forgiving than epoxies. The majority of all fiberglass parts are constructed using Polyester Resins because they are easy to use, fast curing, and tolerant of temperature and catalyst extremes.

Scroll down for more general polyester resin information. To learn more about specific products and pricing, click on an image below.

Sort Products
Products per Page

Polyester Molding Resin
Wax Free, General Purpose Resin

#77 Molding Resin is ideal for general purpose part fabrication and for building low cost molds. It features an internal thickening agent which results in a high thixotropic index. This prevents drainage when applied to vertical surfaces, yet this polyester resin retains the low viscosity required for rapid wet out. As a first quality resin, the color, consistency, and properties of this resin will not vary from batch to batch. #77 is easy to work with and since it is wax free, you don't have to sand between coats.

As a wax-free resin, air must be inhibited during the cure cycle for repairs, single or thin layer applications. To inhibit air we recommend either adding Styrene Wax to the resin, or spraying the applied resin with a coat of PVA. If air isn't inhibited, the resin may not properly cure and remain tacky. For thick or multiple layer applications the heat generated during the exotherm will allow the resin to cure fully.

#77 Polyester resin is formulated for 1.25% MEKP catalyzation. This resin can be purchased alone or as part of a Resin and Hardener Kit.

77/69-F kit contains (1) QUART RESIN, (1) 69-A.
77/69-A kit contains (1) GAL RESIN, (2) 69-A.
77/69-AK kit contains (4) GAL RESIN, (8) 69-A.  
Isophthalic Polyester Resin
Durable Resin for Stable Fabrications

#90 Isopthalic Polyester is perfect for making dimensionally stable polyester molds, fabrication of corrosive service parts, and as a durable repair material for tank linings. This Iso polyester resin offers fast wet-out in spray or hand laminates. When spraying, we recommend using a 1/8" nozzle. The 225 degree F service temperature resists exotherm and post cure problems. #90 has better strength properties than a general purpose polyester resin, which allow it to be used in more demanding applications.
Properly fabricated parts may be used in food contact, electrical and military applications.
#90 Isopthalic Polyester resin is formulated for 1.25% MEKP catalyzation. This resin can be purchased alone or as part of a Resin and Hardener Kit.

90/69-F kit contains (1) QUART RESIN, (1) 69-A.
90/69-A kit contains (1) GAL RESIN, (2) 69-A.
90/69-AK kit contains (4) GAL RESIN, (8) 69-A.  
Styrene Thinner
General Purpose 
#70 Styrene Monomer is the recommended and accepted thinner for polyester resins and gel coats. Most gel coats can be thinned 2-5% to make them suitable for heavy spray equipment or other special purposes.   
Styrene Wax
Get a Complete Cure 
# 71 Styrene Wax is a 5% solution of paraffin dissolved in styrene that may be added to non waxed polyester resins and gel coats to prevent the prolonged tackiness associated with thin sections of polyesters. If the resin contains paraffins, the wax will rise to the surface and protect the curing resin from the inhibiting action of the air. However, if the resin is allowed to fully cure, the paraffins on the surface will prevent adhesion of further coats of resin and must be sanded off prior to additional applications. We recommend adding #71 at 5% for thin coatings. Use with #1040 Hi-Gloss Additive when performing repairs below the water line. 
MEKP Hardener
Industry Standard Catalyst

#69 MEKP is required with all Polyester Resins, Gel Coats and Vinyl Ester Resin. It is required in different concentrations as defined for each resin product. Each resin product is available as a kit with the correct amount of hardener. However, hardener may be purchased individually as shown here.

#77 Polyester Molding Resin is a wax-free, general purpose resin. This resin is a great choice for building low-cost molds, or for general part fabrication. #90 Isophthalic Polyester Resin is a durable, dimensionally stable, corrosion resistant resin. The 225°F service temperature and low shrinkage properties of this resin are ideal for making dimensionally stable molds or extremely durable parts.

Want to learn more about Polyester Resins? Fibre Glast has a free Learning Center with helpful white papers like: About Resins, Mold Construction, Molding Fiberglass, and Fundamentals of Fiberglass. You can also contrast Polyester Resin with Epoxy Resin and Vinyl Ester Resin in the Fibre Glast Blog article: Choosing the Right Resin.

You can place your order right her on our website or, if you have any questions, call 1.800.838.8984 | 8:00am - 8:00pm EST Mon-Fri.

Fibre Glast Blog  Materials Calculator  Shipping Information  ISO Certification