TAP Microspheres • Glass Spheres


TAP Microspheres – Lightweight Filler for Epoxy & Polyester Resins

TAP Microspheres (also known as micro balloons) are ultra-lightweight hollow glass spheres with a particle size of 20–200 microns, designed to enhance the performance and workability of polyester and epoxy resins. When blended into resin, these microscopic spheres displace volume with air, dramatically reducing weight and improving sanding, handling, and flow properties—making them a versatile filler for a wide range of applications.

Key Features & Benefits:

  • Improves Sanding & Workability – Creates a softer, easier-to-sand composite for efficient finishing

  • Lightweight Fill – Displaces 4–6x the weight of resin for low-density, high-build applications

  • Low Shrinkage – Helps minimize cure shrinkage for more dimensionally stable repairs and builds

  • Excellent Flow Properties – Spherical shape acts like tiny ball bearings, improving spread and application

  • Customizable Consistency – Mix ratios range from viscous paste to thick, non-sag filler

  • Economical – More cost-effective than pre-mixed resin fillers

Practical Applications:

  • Ideal for surfboard and sailboard repairs

  • Lightweight fairing and filling compound in marine and automotive fabrication

  • Custom blends for DIY repairs, fiberglass reinforcement, and hobbyist projects

  • Excellent for above-waterline repairs when sealed properly

  • Suitable for gap filling, edge bonding, and smoothing surfaces prior to finish coating

⚠️ Note: Microspheres thicken resin but are not thixotropic, meaning sagging can still occur in vertical applications. A 1:1 volume mix results in a viscous liquid; for a peanut butter-like paste, use a 2:1 filler-to-resin ratio. Microsphere-filled surfaces will become porous after sanding and should be sealed with TAP Premium Marine Grade Epoxy before water exposure.

When mixing with a mechanical mixer, use gentle speed—microspheres are fragile, and excessive force can crush them, reducing effectiveness.

TAP Microspheres are a must-have resin additive for professionals and DIYers seeking to reduce weight, improve impact resistance, and maximize control over resin-based repair and fabrication projects.

Available now at TAP Plastics – explore more resin additives online!

Click here for TAP Microspheres label.