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Will Fiberglass Stick to Plastic? (Read This First!)

Fiberglass is a compound made of several ingredients that give it excessively high structural strength. So, fiberglass is preferred for high-stress applications. But does it work well with the peculiar shapes and shiny surfaces of plastics? 

Rest assured cause we answer all you need to know. 

Will fiberglass stick to plastic?

Fiberglass will stick to plastic. Fiberglass sticks to several surfaces. Plastic is not the most adhesive-friendly surface. Don’t worry cause all you have to do is scuff and prepare the surface where you need fiberglass to stick. Once adhered to the surface, fiberglass stays for a long time.

Fiberglass is very strong and can be used to repair a number of items. Fiberglass is used in a multitude of ways. From truck bodies to aircraft, to boats, to surfboats.

The finished fiberglass adhesion comprises two basic components—fiberglass resin and fiber reinforcement, commonly known as fiberglass matting, fiberglass cloth, etc.

Fiberglass is used to reinforce a number of materials for its versatile use. Plastic comes in different types as well. Fiberglass will have no issue sticking to some while retaining its adhesive properties that seem hard with other plastic types.

Here are two types of typical plastic used on a regular basis.

ABS plastic:

ABS stands for Acrylonitrile butadiene styrene. These plastics are most commonly seen in household items. These plastics are stable, rigid and heat resistant, impact-resistant, and abrasion-resistant.

ABS plastics hardly impose any adverse effects on health. They also do not contain any carcinogens.

Everyday household items made of ABS plastics are vacuum cleaners, kitchen utensils, musical instruments, consumer products, lego toys, etc.

Fiberglass sticks to ABS plastic. Since the surface of ABS plastics is smooth, it will take a little effort to stick. Roughen up the surface, and fiberglass will stick in no time.

Household items and stationeries can easily be fixed with fiberglass resin and cloth. Car bumpers that are of ABS grade can be fixed using fiberglass resin as it sticks to the surface.

HDPE plastic:

HDPE stands for High-density polyethylene. This sort of plastic is widely used in the containers of fast-moving container goods. This chemical is not entirely safe for the human body. HDPE is a low-hazard plastic.

Fiberglass resin does not adhere to polyethylene plastics or HDPE. The chemical composition of HDPE just does not let the fiberglass attach. Even if you scuff up the surface, you will see no result.

So, do not waste your precious time attaching fiberglass to HDPE plastic. The surfaces wrapped by HDPE, such as the external shape of the bumper cover, will not hold fiberglass.

Will Bondo fiberglass stick to plastic?

Yes, Bondo fiberglass sticks to plastic. Plastic products are durable, but they can easily form cracks or break over time. Fixing the products can be troublesome, but with the proper adhesives, it gets easy.

Bondo fiberglass is an all-purpose solution to fixing and sealing cracks and breaks and filling holes. So, it is obvious that, as an adhesive, Bondo fiberglass is a waterproof resin that does all the job effortlessly.

But Bondo fiberglass is not recommended for heavy applications. Large plastic components can be fixed together with Bondo fiberglass, but the bond will not be long-lasting.

For short-term fixing and sealing, you can use Bondo fiberglass as it sticks to plastic. It is used extensively in automotive and household usage.

As a matter of fact, plastic is a difficult surface to bond to. So, if you are thinking of large plastic chunks, you need something that bonds better than Bondo fiberglass.

Can you use fiberglass to repair plastic?

Yes, you can use fiberglass to repair plastic. Fiberglass forms strong bonds that last a long time. You might face some difficulties sticking fiberglass on smooth surfaces, but you can easily overcome it with a little bit of scuffing.

There are different types of adhesives available such as superglue, epoxy, multipurpose glues. Their usage depends on their application and the types of plastic. Like adhesives, there are several types of plastics as well.

Fiberglass comes in handy, repairing all types of plastic breaks and cracking. Essential plastic items can crack, and you have to replace the whole thing. But not anymore since you can easily use fiberglass to repair and reuse your damaged plastic.

Boats, buckets, torches, mugs, flowerpots, and other regular items that are made of plastic can be repaired with fiberglass. Add more layers of resin and fiberglass to give rigidity.

Three reasons why fiberglass sticks to plastic

Fiberglass does not adhere to every sort of plastic. There are plastics that fiberglass does not adhere to at all. And there are plastics on which fiberglass form a weak bond.

However, most of the plastic surfaces could stick to fiberglass. 


As stated before, the two essential elements of finished fiberglass products are fiberglass resin and fiberglass cloth. The resin dries fast into a brittle solid.

The fiber reinforcement is placed in the desired place where the resin is poured or applied. The liquid resin hardens and gives the final shape to both components.

There is various type of fiberglass reinforcements that varies in thickness. The thicker the material, the more solid the bond. So, this fiberglass easily sticks to plastic.

Materials with adhesive properties:

The principal materials used in preparing fiberglass are silica sand, limestone, and soda ash. Other ingredients such as borax and magnesite help it to contain its shape.

When fiberglass materials come in contact with liquid resin, the fiberglass becomes transparent and forms a tremendously solid structure.

Now you get the job done when you place this essence on the item that requires repairing.

The fiberglass’s adhesive quality combines with plastic and gives it long-lasting stability.


Plastics are easy to bend, so there are a lot of products with peculiar shapes. Therefore it becomes a challenging task repairing damages in weird corners.

The fiberglass matt can conform to complex shapes and compound curves. So, it makes sticking to plastic surfaces much more manageable.

How to make fiberglass stick to plastic?

Sticking fiberglass to plastic is no challenging task. You can fix your plastic items or join them easily with fiberglass and resin. You will not find straightforward guidelines about plastic on the product containers.

You need the following materials.

Gloves, mask, fiberglass matting, resin or epoxy, measuring cup, isopropyl alcohol or acetone, grit sandpaper, disposable paintbrush, and fiber cloth. Follow these steps to make fiberglass stick to plastic.

Cleaning the surface:

First, wear gloves and a mask. You can also wear full cover if you do not want your dress to get dirty.

Using fiber cloth, clean the surface where you want to attach fiberglass. Use acetone or isopropyl alcohol, whichever is more convenient.


This is the essential part as fiberglass does not adhere to smooth surfaces. Use sandpaper and scuff the surface you just cleaned. Do not apply too much pressure as you will damage the surface.

Applying resin and fiberglass:

This is the tricky part. You can apply epoxy or resin. For epoxy, follow the guidelines stated in the container. If you prefer fiberglass resin, then follow the orders given on the container.

Some manufacturers will suggest using catalysts; therefore, you should look into the instructions carefully. Apply the solution in small amounts on the surface.

Cut fiberglass according to size and press evenly with a soft brush. You can apply more than one layer of fiberglass, but the sizes have to be evenly cut. Apply more resin or epoxy on the fiberglass.


Wipe off excess resin and leave the item for a day undisturbed.

What will fiberglass resin not stick to? What plastic does fiberglass resin not stick to?

Even though fiberglass is known for its adhesive properties, there are surfaces where fiberglass does not stick. Fiberglass resin does not stick to smooth surfaces.

Woods that are pressure-treated will not hold fiberglass resin. Fiberglass resin only sticks to untreated, dry wood. Typical untreated redwoods having a waxy layer will not hold fiberglass either.

Fiberglass resin does not stick to glass either, although it has glass. You will have a hard time sticking fiberglass resin to surfaces that have a smooth texture. That includes steel, plastics, aluminum, and many more.

Other materials that fiberglass does not adhere to are Teflon, nylon, polypropene, polypropylene, polyethylene, polyvinyl chloride.

The plastics that fiberglass resin does not stick to are polyethylene plastics, polypropylene plastics, and polyvinyl chloride plastics. These are disposable plastics products like bags or sheets.

Final Thoughts 

The application of fiberglass depends on the material type and weight, fiber direction, and weave of the fiberglass. While fiberglass sticks to most plastic surfaces, it does not stick to some. Contact the manufacturer to see if it is compatible with fiberglass for repairing plastic materials.