How to Cut Fiberglass – 6 Tips for Cutting Fiberglass in the Best Way


Due to fiberglass’s nature and character, cutting fiberglass panels may not seem like one easy task to accomplish. It is not because fiberglass’s inner structures are held tightly together, making cutting difficult, but for safety reasons.

Therefore, it is essential to pay attention to safety practices on cutting fiberglass, for example, keeping the fiberglass panels from splintering or throwing harmful fibers towards the body’s delicate area.This article will get you informed with the best methods on how to cut fiberglass to ensure safety.

Cutting of fiberglass

Figure 1: Cutting of fiberglass.

Section 1: What is Fiberglass

1.1 What is Fiberglass

Fiberglass is a type of fiber-reinforced plastic, which you can also refer to as glass-reinforced plastics. It consists of plastic, glass, and glass fiber, making it a versatile material for various uses.

Fiberglass is a robust, lightweight, and less brittle material that you can mold into different complex shapes and sizes. Hence, it explains much about its versatile application in bathtubs, boats, aircraft, roofing, and other usages.

However, depending on fiberglass’s application, the glass fiber can consist of different glass types and forms. The term fiberglass may also mean fiber strands fused into plastic.

Fiberglass is cost-effective; it’s less costly and more flexible than carbon fiber.

 Fiberglass sheet

Figure 2: Fiberglass sheet.

1.2 Types of Fiberglass

  1. A-Glass: A-Glass fiber is also commonly referred to as alkali glass; it is quite resistant to chemicals. Window glasses contain compositions of A-glass fiber and have used for process equipment.
  2. C-Glass: The C-Glass fiber type is more resistant to chemicals, commonly referred to as chemical glass.
  3. E-Glass: As the name may already suggest, it may also be referred to as electric glass, making an excellent electrical insulator.
  4. AE-Glass: This glass is resistant to alkaline.
  5. S-Glass: The S-Glass is known for its good mechanical properties; it is also called structural glass.
Fiberglass making in progress

Figure 3: Fiberglass making in progress.

1.3 Properties of Fiberglass

Fiberglass has various applications due to its favorable properties; And below are some of the most important properties.

  1. Mechanical Strength: Fiberglass has a higher specific resistance, making it suitable for high-performance applications. In addition, it is responsible for having methods/tools on how to cut fiberglass.
  2. Electric Characteristics: Fiberglass is an excellent electrical insulator. Its insulation capability is not affected by thickness.
  3. Dimensional Stability: Fiberglass has a low coefficient of linear expansion; therefore, it is not affected by hygrometry or temperature changes.
  4. Thermal Conductivity: Building constructors use fiberglass because of its low thermal conductivity.
  5. Dielectric permeability: These properties make it useful in electromagnetic window application.
  6. Non-Rotting: It does not rust either is it affected by insects or rodents.
  7. Compatibility with organic matrices: Fiberglass is compatible with various chemical/organic compounds, synthetic resins, and matrices like cement.
  8. Incombustibility: Fiberglass has a high resistance to fire. It is non-flammable and does not support flame or smoke.

Section 2: What we need to consider to choose a tool for cutting fiberglass

2.1 Tips For Cutting Fiberglass Panels 

Fiberglass is a hard material; despite its versatile use, it is essential to use the right gears. It is vital to know how to cut fiberglass. Unlike other construction materials like plywood, fiberglass requires several precautions for a clean and safe cut. For straight cuts, a table saw or hand-held circular saw is sufficient.

However, for curved cuts, a saber saw or hand-held jigsaw will do a fine job. 

Using the right fiberglass cutting tool and a proper handling technique will help prevent splintering along your cut line. The fiberglass panels are flexible than plywood; as explained, they are brittle, requiring a smooth surface for support.

Fiberglass panel

Figure 4: Fiberglass panel. 

2.2 Blade Considerations

Also, knowing how to cut fiberglass with the right blade helps improve the perfectness of the cut to a great extent. Manufactures of reinforced fiberglass panels prescribe the blade considerations—a blade with a carbide-tipped cutting tooth and a high tooth or the fine-tooth count. In most cases, the number of teeth on edge will vary with the blade’s size.

We say a bigger blade with the largest number of teeth is suitable for cutting. Similarly, a jigsaw or a saber saw would have almost the same number of teeth and a carbide tip.

Section 3: Best tools to cut fiberglass panels.

3.1 Jigsaw

The jigsaw is one of the best tools you can use in making a precise and clean cut on a fiberglass plane. It is a powerful tool to use as it ensures accuracy, control, and safety. The jigsaw can come in handy with your knowledge of how to cut fiberglass.

3.2 Reciprocating Saw

A circular saw is a powerful tool with several circular blades of different pitches. Moreover, it allows you to select an edge depending on what you want to cut.

3.3 Circular Saw

A circular saw is a powerful tool with several circular blades of different pitches. Allows you to select an edge depending on what you want to cut.

3.4 Hacksaw

A hacksaw is a hand tool useful for making small precise cuts. It is an excellent tool though it will require some level of patience.

3.5 Router

The router tool is useful if you make a curved cut or sharp edge cut on your fiberglass. It gives tremendous precision for curved edges.

3.6 Cut-Off Wheel

This fiberglass cutting tool comes with a thin grinding wheel or metal disc with a smooth edge. It is suitable for making shapes that involve the use of a particular technique.

Cutting of roofing sheet fiberglass

Figure 5: Cutting of roofing sheet fiberglass.

Section 4: How to cut fiberglass

4.1 How to Cut Fiberglass– Place the cloth on the hard table.

Place and stretch out the fiberglass sheet on a hard-working table. Ensure the surface of the table is clear of any particle or solid. The area you want to cut out should be on the table.

4.2 How to Cut Fiberglass –Pull out fabric strands along the cutting edge.

Some fiberglass used previously will have some light, loose strand on it around the bottom edge. To ensure you have a clean-cut, you should remove them by pulling them out. This step ensures the fabric is durable and has full strands.

4.3 Square up the fabric with the edge of the table.

Make sure to align the fabric’s border with that of the stone table to avoid a crooked cut. A tee-square could come in handy in this step.

4.4 Smooth out the fabric.

Do this by spreading your palm gently over the fabric’s surface to eliminate any bumps or wrinkles.

4.5 Cut the fiberglass.

Make use of a precision blade or a sharp knife to cut along the line you have marked. Carefully do that by cutting across the line. Make sure to be steady and stay still. Nevertheless, having a guide around while cutting fiberglass is necessary and beneficial.

Section 5: How to Cut FiberglassThe best way to cut fiberglass panels

5.1 Cutting straight lines in Panels

Place your fiberglass panel on a hard surface, a working table, preferably a firmly fitted, sturdy table. If cutting in the middle of the fiberglass panel, you might need a second table with the center hanging. Draw a line across the fiberglass panel to indicate your path of cutting.

Furthermore, ensure you clamp the fiberglass panel to the table firmly, ensure it fits tightly to avoid cutting out of line. Then, you can cut with your preferred cutting tool.

5.2 Making Curved Cuts in Panels

Again, secure your panel on a hard work table. If your cuts will fall in the middle of the fiberglass panel using a second table. Furthermore, use a thick shade pencil or a marker to trace your curve’s pattern; ensure it is bold. In addition, make a slight hole by using a power drill to drill through the fiberglass panel. Giving the saw an area to enter and exit quickly. Also, please make use of a jigsaw, cutting it carefully. Use a file to clean out the cuts. It is one of the best ways on how to cut fiberglass curves because it gives precision.

5.3 Sawing small Pieces and Panels

After securing the pieces and panels on a sturdy work table, arrange them correctly without wobbles. Cover the area you plan to cut with some tape just a little beyond the scope. Now, mark the glue tape with your cutting line, ensure to make an accurate measurement. Then you can now make your cut with a hacksaw by moving the hack saw back and forth.

Section 6: How to Cut FiberglassHow to protect yourself when cutting

This article shouldn’t only include cutting fiberglass methods but also how to protect yourself while you cut. Your safety should be of paramount importance to you when cutting; therefore, you should use all safety gears when cutting. Wear a thick long-sleeved overall, use thick hand gloves, wear goggles, dust masks, work in a large open space.


In conclusion, we have been able to address the properties of fiberglass responsible for its versatility. More so, some techniques shared on how to cut fiberglass are explosive.

We have also discussed specific cutting tools for cutting fiberglass and cutting straight lines, curves, and small fiberglass panels.

Lastly, we discussed how to protect ourselves while cutting. At NCCuttingtools, we provide various cutting tools alongside related customized services. At all times, we are always available to serve you at any time, any day.

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