The first step in the fiberglass mold building process is to create a plug. A plug is the form which is to be duplicated and is usually a representation of the finished part. This can be an actual part, a reproduction, or a completely new form. In planning for the mold, certain factors must be taken into consideration; surface finish, draft angles, undercuts, and method of production. A quality mold surface begins at the plug stage. Every imperfection on the plug surface will be transferred to the mold, and to all subsequent parts. The preferable surface finish for the plug would be a Class "A" finish, which means it would be a polished, high-luster finish, free from any porosity or scratches.

Fibre Glast offers everything you will need to create a durable, high-gloss, Class 'A' finished plug, from polyisocyanurate foam, modeling clay, reinforcement and fairing compound to surfacing primer and mold release products.

Photo Credit: John Gregg, Gregg Drilling & Testing Inc, Signal Hill, CA.

  • 4 oz Fiberglass Fabric

    Conformable and Lightweight Fabric for General Use
    5 star rating
    This 4-ounce Plain Weave Fiberglass Fabric is our most popular selection for use as a surface fabric, with...
  • 6 oz Fiberglass Fabric

    Molded Parts and Repairs in Just a Few Layers
    5 star rating
    The 6-ounce Plain Weave Fiberglass Fabric is popular for molded parts and repairs. For waterproofing...
  • Isophthalic Polyester Resin

    Build Strength and Stability for Tough Parts
    4.9 star rating
    #90 Isophthalic Polyester is perfect for fabricating dimensionally stable polyester molds and corrosive service...
  • Polyester Fairing Compound

    Durable and Highly Adhesive with Low Shrinkage
    5 star rating
    Polyester Fairing Compound is a fibrous filler for structural repairs, bonding, and part fabrication. This...
  • 1 Liter High-Pressure Gel Coat Spray Gun

    The Capacity and Customization Needed For Any Project
    5 star rating
    The #134-A 1 Liter High Pressure Gel Coat Spray Gun is ideal for larger repairs and small to medium projects, with a...
  • 0.6 Liter Gel Coat Touch-Up Spray Gun

    Customize your Spray Pattern for Heavy-Duty Jobs
    5 star rating
    Not every spray application is the same. Why not have one gun that allows you to adjust spray width and volume? Our...
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  • Parting Wax

    Simple and Reliable Mold Release Wax
    4.8 star rating
    Parting wax is a non-silicone green wax specially formulated to produce a tough, durable, high-gloss surface. When...
  • PVA Release Film

    Easy Spray-On – Easy Release for Molds
    4.9 star rating
    PVA, or polyvinyl alcohol, should be used with our #1016 Partall Wax for the easy release of parts from a mold. Wax...
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