Duraglas Fiberglass Filled Filler 1 Gallon - Strong Waterproof Auto

Our review of Duraglas Fiberglass Filled Filler finds it best suited for DIYers and professional body shops that need a durable, reinforced repair material for rusted panels and damaged fiberglass. The single biggest reason to buy is its short-strand fiberglass reinforcement, which provides superior strength compared with ordinary putty and holds up well on welds, bond seams and large patch jobs. It mixes 2% by weight with the supplied cream hardener and cures into a waterproof, rustproof repair that accepts finishing putty or All-Metal top coat for a sealed result.

Key Features

• Fiberglass reinforcement: Short-strand fiberglass fibers are blended into the filler to deliver extra tensile strength on cracks, holes and rust-outs.
• Metal and fiberglass use: Formulated to adhere to both metal and fiberglass panels so one product can handle mixed-substrate repairs.
• Waterproof and rustproof: The cured filler resists moisture and prevents further corrosion when used correctly on rust repairs.
• Works with fiberglass cloth: Can be used with cloth for large repairs to build structure and reduce sag in vertical patches.
• Finishing compatibility: Accepts All-Metal as a top coat and can be shaped with finishing putty for a smooth final surface.

Who It's For

Duraglas is aimed at automotive and marine repairers who need a strong, long-lasting filler for rusted body panels, holes and fiberglass tears. It suits experienced DIYers and shops that can weigh and mix at the recommended 50:1 ratio and work quickly with a cream hardener for fast set times.

Those who should look elsewhere include casual users who prefer premixed or squeeze-tube products and anyone uncomfortable measuring by weight or working with a separate hardener. For tiny surface blemishes a standard finishing putty alone may be simpler.

Pros & Cons

Pros

• Excellent adhesion to metal and fiberglass for reliable patch repairs.
• Reinforced with short-strand fiberglass for greater structural strength than plain putty.
• Waterproof and rustproof once cured, making it suitable for marine and exterior use.
• Compatible with fiberglass cloth and All-Metal top coat for larger or sealed repairs.

Cons

• Requires measuring by weight and mixing with a separate hardener, which adds steps compared with ready-mixed products.
• Some customers report occasional issues with damaged cans, so inspect packaging on arrival.

Specifications

Product	Fiberglass filled body filler
Volume	1 gallon
Fill type	Short-strand fiberglass reinforced
Mix ratio	2% by weight (50:1) with supplied cream hardener
Suitable substrates	Metal, aluminum, fiberglass, wood, masonry, concrete
Suggested use	Rust repairs, cracks and holes in fiberglass, weld areas and bond seams
Color as packaged	Blue-green

Our Verdict

Duraglas Fiberglass Filled Filler is a practical choice for anyone tackling structural body repairs that need reinforcement and waterproofing. Its fiberglass content and substrate versatility make it good value for shops and serious DIYers, provided the user is comfortable mixing to the recommended ratio and working with a separate hardener.

Frequently Asked Questions

Can Duraglas be used on both metal and fiberglass?
Yes. It is formulated for adhesion to metal, aluminum and fiberglass and is recommended for mixed-substrate repairs.

What is the proper mix ratio?
Mix 2% by weight (a 50:1 ratio) of filler to the supplied cream hardener for correct curing.

Is the cured repair waterproof?
When cured and finished properly, the filler is waterproof and rustproof and can be sealed with All-Metal top coat for a completely watertight repair.