How To Successfully Drill Through Fiberglass?

Drill Through Fiberglass

Fiberglass is an enduring and protective sheet that can last half of your lifetime. Nowadays, the use of fiberglass is rapidly increasing. Fiberglass enhances the decorative beauty of your place. It’s a composite material made of various polymer products, resulting in a heavy-duty glass fiber. Fiberglass is purchased in the large glass sheet form and needs to be cut and drilled into different sizes to make it fit for use. Drilling through fiberglass may seem like a complex task. This article gives you a brief overview of fiberglass drilling and answers to the most common questions people frequently ask. 

What Kind Of Drill Bit Is Best For Fiberglass?

Everybody wants a clean hole with smooth edges while drilling through fiberglass. Although drilling fiberglass is not a complex task, people often crack the glass due to unmindfulness. 

The diamond drill bit is a perfect choice for drilling through glass, fiberglass, ceramic, stone, marble, granite, etc. Manufacturers cover the head of this drill bit with small diamond powder, which gives a distinct advantage in drilling. We know that diamonds are a rigid material, so when drilled with the help of a diamond drill bit, its edges become well-measured and smooth. However, you can easily make holes into tiles and glasses with it. But if the surface is thick, using some cooling liquid gives a better finish. 

Drilling Methods

There are two methods for drilling into fiberglass – the bedding method and the plug method. You can use the Bedding method to drill objects in dry places such as doors, floors, boat top bodies, etc. And the plug method is used to drill any surface with a complicated situation like underwater or air level. The bedding method is also needed while using the plug method.

Bedding Method

Bedding is the most popular method for drilling fiberglass. Here, you have to add bedding compounds after drilling to make the hole ready to use. Then you can add screws or bolts to the hole. Use enough bedding compounds to seal the hole properly so the air or water can’t break in. 

Plug Method

The plug method is advantageous if you want to make an air or watertight hole with coring material. In this case, make holes that are slightly larger than required (e.g., 50% larger) and use epoxy to seal them completely. Try to set the epoxy slowly (e.g., 18 to 24 hours) as this gives the glass laminate more time to get wet, which increases its durability.

Then make another hole with the required measurement following the bedding method as required.

Drilling Into Fiberglass

Start your fiberglass drilling by making a spot mark with something sharp. The spot holds the indentation of your drilling and prevents you from wandering or unintentionally scratching on the grilling surface. 

Then move along with drilling small holes than needed. Keep your speed as low as possible to avoid chipping. Also, let the drill pressure stay natural; try not to push the machine.

Later, drill holes according to the size you need to drill. Try to keep the bezel of the hole slightly sloppy (e.g., 1/16 inch). When drilling, you need to keep the hand steady and hold the drill machine to get a lovely finish. If you apply pressure while drilling, the glass will likely be damaged.

Use a sharp and clean drill bit. Have a stronghold of your gear, and don’t shake it. Otherwise, it will make the hole perpendicular. 

We mentioned earlier that fiberglass drilling is a bit laborious. So, hold your patience, and let the machine do its job. A perfect drill finish requires patience and steadiness. 


A few questions usually arise among the newbies while drilling fiberglass. However, there is nothing to worry about if you follow the proper procedure.

Can you drill a hole in fiberglass without cracking?

Obviously, YES! To avoid cracking, use an appropriate drill bit according to your drill size to avoid cracking.

Is it safe to drill into fiberglass?

There are a few safety measures you should maintain while drilling through fiberglass. However, you should use eye protection and hand gloves. You can also use earmuffs when necessary. 

Will screws hold in epoxy?

Epoxy is a durable mixture that you can use on home repairs or fill any hole. If you let enough time dry the epoxy, you can drill through it. In the Plug method, epoxy is necessary to make the hole airtight/waterproof.

Do you need a particular drill bit for fiberglass?

Try to use the Diamond drill bit that is fresh and sharp to make perfect holes through fiberglass. 

What speed should I drill fiberglass?

Drilling a perfect hole into fiberglass is time-consuming. So, it is advised to drill slowly and not put extra pressure on the drill.

Drilling through fiberglass may be an intimidating task. You need to keep in mind two main things – proper drill bits and patience. Follow the stated process, and you will have perfect holes through your fiberglass. 

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