Does Fiberglass Rust?

Fiberglass has many favorable characteristics which contribute to its popularity. It features several useful properties for commercial and industrial use, such as thermal and acoustic insulation and good fire resistance, to name a few. But one area where fiberglass can fall short is when asked, does fiberglass rust?

No, fiberglass does not rust. It is a reinforced plastic material created by combining plastic resin and fine fibers made from glass. It can be used to make boats, shower stalls, building materials, car parts, or even furniture.

The information on this page reveals all you need to know about fiberglass. Therefore, I suggest you read further for more information

What causes rust?

Rust itself forms on steel, iron, and other metals when there are different charges between oxygen and the metal. Oxygen and steel are attracted to each other, which is more like a magnet. Oxidation or rust as you know is the final result when they both attract each other and combine.

What causes rust

You can never witness rust without the super presence of steel and that now is exactly why fiberglass does not rust, it does not carry the chemical makeup of the steel present in it. As stated above, fiberglass gets its properties from resin and glass. It can be very similar to steel but not metal. Fiberglass is very strong and stiff.

Properties of Fiberglass

  • Mechanical strength: fiberglass has a high value of mechanical strength. When compared to steel, it can be said to be almost similar hence it is used for several things that require high performance.
  • Electrical and thermal characteristics: fiberglass does not conduct heat or electricity at all. However, even when at a very low thickness, fiberglass serves as a very good electrical insulator.
  • Combustibility: fiberglass is naturally a mineral material. So, it is naturally incombustible. It does not for any reason support a flame, it does not bring out smoke or any toxic products whenever it is exposed to heat.
  • It cannot rot: rodents, insects, and natural causes cannot affect fiberglass, so it does not get rotten at all.

Comparing Fibreglass And Steel

There are several similarities between fiberglass and steel as both of them are very tough and strong. The main difference comes when comparing their resistance to corrosion as steel corrodes while fiberglass does not.

Comparing Fibreglass and steel

Fiberglass is very tough and very resistant to water. It has this stability because it does not readily absorb water, hence experiencing little expansion and contraction. There are several types of fiberglass materials such as FR4, G10, and Garolite. All of them have great stability around water and that makes them perfect for making circuit boards, bathroom components, and even marine applications.

Can Fibreglass Repair Rust?

By layering fiberglass on the rusted part of the metal and sealing the surface, you can use fiberglass to stop rust. Here is a quick run-down of how to do it.

Can Fibreglass Repair Rust

1. Clean out the surface

The particular area on the surface which needs to be repaired should be cleaned. For this, you could wash the area with soap and water or acetone after which the affected area should be cleaned using either a wax or a grease remover. After cleaning, you can apply metal conditions and use a clean piece of material or foam to rub it off quickly. To ensure precision, many people use masking tape.

2. Cut out the needed size of the fiberglass

To get this right, you would need to lay the fiberglass on a hard surface and cut out the needed size using a knife or razor.

3. Adding a filler

Fiberglass resins can be got from the hardware store and mixed with the right solvent or catalyst based on the instruction. Once you get the right consistency, you would have to work quickly else it would get hardened and unusable in not more than 30 minutes.

4. Sticking the fiberglass to metal

Apply the resin to the surface of the metal and on the fiberglass mat to stick them together. You might need to run a roller over the mat to get out any trapped air bubble for a perfectly smooth fix.

How to Clean Fiberglass

Because of its rust resistance, fiberglass is often placed in areas that are exposed to water such as the bathroom. To keep your fiberglass material looking good for a long while, it is necessary to keep it clean. Fiberglass is cleaned with very soft non-abrasive products such as a soft brush and a gentle cleaning agent. If there are discolorations or stains on the fiberglass, you could use acetone to remove those.

Industrial Uses Of Fiberglass

Fiberglass in itself is durable, safe, and offers high thermal insulation. These are the main reasons why fiberglass is generally needed and used in most industries such as

Industrial Uses Of Fiberglass

  • The beverage industry: fiberglass grating is so useful in so many areas such as bottling lines and also in brewhouses.
  • Car washes: fiberglass can also be used for building areas that must be rust-resistant and to give a contrasting color to some parts that formerly looked bad. It can light up the inner part of the carwash tunnel and that would make the car look cleaner than it was.
  • Docks and Marinas: the docks can originally get rusted, corroded and can also get damaged by seawater which is salty. Bearing that in mind, fiberglass can be used as a means of protecting metals from rust and damages.
  • Food processing: fiberglass is used for surfaces especially in businesses that involve the processing of chicken and beef. This is a necessary help because blood can be very corrosive.
  • Fountains and Aquariums: no matter the size of fountains and aquariums, it must use fiberglass to support rocks which assist in circulating and filtering from under the rocks. Fiberglass is used for the lights and spray headers to prevent them from rusting.


Fiberglass is a natural material that finds usage in several areas because of its strong resistance to rust and corrosion. Because it is composed of natural oxides and not metal, it cannot rust hence it is more durable.

Fiberglass comes in a number of appealing colors and types that beautifully light up the area. You would have to decide with an expert before selecting what works best for your project.

Evan Cooper

Evan Cooper

Hi, I’m Evan Cooper, the founder and an editor of this site, Doesitrust. I’m a chemical engineer and working in a rust-eliminating paint manufacturing company. Besides this profession, I’m a researcher and blogger.

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