How Are Fiberglass Tanks Made?

In the realm of industrial storage solutions, filament winding technology represents a significant advancement, particularly in the manufacturing of fiberglass tanks. This process not only enhances the mechanical strength and durability of tanks but also offers remarkable precision and uniformity, which are critical for high-performance applications.

This article explores the filament winding process used for fiberglass tanks, its benefits, and why it’s a preferred method in various industries, including chemical, water treatment, and oil and gas.

KBK Manufactures Long-Lasting and Durable Fiberglass Tanks

Understanding Filament Winding

Filament winding is a fabrication technique primarily used for creating open or closed end structures like pressure vessels, pipes, and, of course, storage tanks. It involves winding continuous fibers (usually glass, sometimes carbon or aramid) soaked in a resin matrix over a rotating mandrel to form the tank.

Process Details:

Mandrel Setup: A mandrel (a mold tool) is configured to the desired dimensions of the final tank. It rotates on its axis throughout the process.

Fiber Delivery: Roving fibers, typically glass, are fed into a resin bath to impregnate them with a thermoset resin, often epoxy, polyester, or vinyl ester.

Winding: The resin-coated fibers are wound around the mandrel in a precise geometric pattern. The patterns—typically helical or hoop (circular) windings—depend on the end-use requirements concerning strength and pressure resistance.

Curing: After winding, the tank undergoes a curing phase where the resin hardens, and the fiber-resin matrix solidifies.

Extraction and Finishing: The hardened tank is extracted from the mandrel and goes through finishing processes, including trimming, drilling, and adding fittings and accessories.

fiberglass tank

KBK Uses the Latest in Automated Winding Equipment.

Advantages of Filament Wound Fiberglass Tanks


Enhanced Structural Integrity

Uniform Thickness: The controlled filament winding process ensures uniform thickness and density, which eliminates weak spots prone to cracking and leakage.

High Strength-to-Weight Ratio: Fiberglass tanks manufactured through filament winding are lighter yet stronger than those produced by other methods, making them easier to install and more durable under pressure and stress.

Superior Corrosion Resistance

Chemical Compatibility: The choice of resin can be tailored to the specific chemicals the tank will hold, providing superior resistance to corrosion and chemical attack.

Long Lifespan: These tanks withstand harsh chemicals and environments without deteriorating, promising a longer service life with less maintenance.


Reduced Manufacturing Costs: The automation of the filament winding process allows for quicker production times and less manual labor, which in turn reduces manufacturing costs.

Low Maintenance: The durability and corrosion resistance of filament wound tanks mean that they require less upkeep, which lowers the lifetime cost of ownership.

Design Versatility

Customizable Shapes and Sizes: Filament winding allows for flexibility in tank dimensions and capacities, which can be customized to specific storage needs without compromising performance.

Aesthetic Options: The outer surface of these tanks can be finished in various textures and colors, offering aesthetic versatility in addition to functional superiority.

Applications in Industry

Chemical Storage: Chemical manufacturers prefer filament wound fiberglass tanks because they can be customized to resist specific chemicals.

Oil and Gas: The oil and gas industry utilizes these tanks for storing crude oil, saltwater, and chemicals, benefiting from their corrosion resistance and strength under pressure.

Water Treatment: Filament wound tanks are ideal for municipal water treatment applications due to their longevity and ability to hold large volumes of water or treatment chemicals under varying temperature conditions.

Agriculture: These tanks are used in agriculture for storing fertilizers and pesticides, substances that require robust containment solutions to prevent leakage and environmental contamination.

KBK Operates More Filament Winders Than Any Tank Manufacturer in the Nation.

The filament winding process for fiberglass tanks offers unparalleled benefits in terms of strength, durability, and cost-efficiency. This manufacturing technique not only meets the high standards required in many industrial applications but also provides flexibility in design and a promise of long-term reliability.

As industries continue to demand more robust and adaptive storage solutions, filament wound fiberglass tanks stand out as the superior choice, ready to meet these evolving needs with excellence and innovation. KBK is the leader in manufacturing fiberglass tanks utilizing the filament winding process.