Fasco Epoxies White Glass Microspheres – Lightweight Resin Filler (Quart Tub)

Product at a glance

Fasco Epoxies White Glass Microspheres are engineered hollow glass spheres designed to be mixed into epoxy or polyester resins as a lightweight filler and reinforcement. Packaged in a convenient quart tub, these microspheres are white in color and are commonly referred to as glass bubbles in resin communities. They’re designed to blend smoothly with resin systems, helping you add bulk without adding heavy weight.

Why choose these microspheres

In resin work, the goal is often to balance weight, strength, and workability. These hollow glass microspheres offer a practical solution by adding volume while keeping the cured part easy to sand and shape. The white appearance can help you visually assess coverage during application, and the uniform particle geometry supports consistent performance across batches.

• Sands easily, enabling lightweight fairing compounds when added to epoxy or polyester resins
• Also commonly known as glass bubbles, a familiar term in resin circles
• Helps optimize the weight-to-strength balance and supports dimensional stability in cured resin
• When mixed with Cabosil in equal parts by volume, forms a versatile general-purpose putty
• Engineered hollow glass microspheres provide consistent performance and easy handling

How to use

Begin with small test portions to dial in your desired texture. Stir the microspheres into resin until uniform, then proceed with your normal curing process. For putty applications, combine equal parts by volume with Cabosil to achieve a smooth, work-ready paste.

Real-world applications

These microspheres are well-suited for lightweight fairing on panels, temporary patches in molds, or bulk filling where reducing weight is helpful. The white color helps with visibility during application, and the hollow structure supports smoother finishing operations after cure.

Care and storage

• Store in a cool, dry place to maintain performance
• Follow resin manufacturer guidelines for mixing ratios
• Perform a small preliminary test batch before larger projects