Milled Glass Fiber

Milled Glass Fiber


Finely ground fiberglass fibers can be mixed into epoxy systems and polyester resins to increase tensile strength and flexibility, as well as reduce shrinkage. Most often used in structural filleting putties.

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  • Finely ground, short fiberglass filaments ideal for creating fine fillets and filling gaps
  • Increases dimensional stability and impact strength while minimizing shrinkage and distortion
  • Wear proper safety protection when blending Milled Glass Fiber and other fillers into mixed resin/hardener
  • Can be used alone or blended with TotalBoat Silica Thickener (sold separately) to prevent sagging on vertical and overhead surfaces
  • Product Color: White
  • Cured Color: Off-white
  • Sizes: Available in 1-Quart and 5-Quart sizes

Where to use TotalBoat fillers

Milled glass fibers are commonly used when epoxy must fill a void, provide high strength, and high resistance to cracking. Examples include structural filleting, bonding hardware, and keel bedding. TotalBoat fillers can be used with either epoxy or polyester resins to change the resin properties for various uses, such as bulking out the resin or making it easy to sand. Because fillers can affect the pot life of a resin, create a small trial batch first to determine how much working time you’ll have.

Glass Microballoons Milled Glass Fibers Silica Thickener
Fairing ✔ (blended with Glass Microballoons)
Filleting ✔ (blended with Glass Microballoons)
Vertical Surfaces ✔ (in thick enough concentration)
Reducing Shrinkage
Reducing Weight
Surfboard or Sailboard Repair


TotalBoat Milled Glass Fiber SDS

Frequently Asked Questions

What are Milled Glass Fibers used with epoxy for?

Milled glass fibers are used in epoxy systems to increase tensile strength and flexibility, and it’s formulated to help reduce shrinkage. It’s ideal for use in situations where you must fill a void because it’s very high strength and provides resistance to cracking. Examples include structural filleting, bonding hardware, and keel bedding.

Which epoxy system should you use with Milled Fibers?

You can use both 2:1 and 5:1 epoxy resin systems with Milled Fibers.

Can you mix Milled Glass Fibers with other fillers?

Yes, you can blend Milled Glass Fiber and other fillers into a mixed resin/hardener.

Why would you combine Milled Fibers with Silica Thickener?

Combining milled fibers with Silica Thickener will strengthen the resin to prevent sagging and draining on vertical and overhead surfaces.

Can you use Milled Fibers with polyester or vinyl ester resin?

Milled Glass Fibers are chemical-resistant, so they are often used with both polyester and vinyl ester resin in putty form for deep blister repair on boats.

How much should you add to epoxy?

Add 5% of Milled Glass Fibers by weight to the epoxy after it has been catalyzed to increase the tensile strength without negatively affecting pourability.

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