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​How To Cut Fiberglass



Fiberglass can be one of the most attractive things about your boat. It can also be one of the most complicated parts of the boat that you have to deal with. If you ever find yourself in a situation where you need to trim or cut fiberglass to handle repairs or give it a cosmetic update, it can feel tricky. That’s why we’ve put together a brief guide on how to cut fiberglass safely and easily.

Why Cut Boat Fiberglass?

Usually, cutting into a boat’s fiberglass is the result of installing something new—for example, a new radio. If you want to add that to your boat and minimize the amount of space you use, you’ll often have to cut into the fiberglass. When you purchase a product designed to be installed directly into fiberglass, you’ll find it often comes with many of the pieces and instructions you need to get going.

Prepping Your Fiberglass

Make sure you’re working on a relatively clean, smooth surface. You don’t want to cut into the fiberglass and cut your hand on anything jagged.

Using the suggested measurements of the product you’re installing, it’s time for you to mark out the area you’re going to cut through. Remember the phrase “measure twice, cut once”? It’s just as true for fiberglass as it is with wood. Make sure that your measurements are precise, and measure once more to double-check. It seems like an extra step, but it’s really the best way to ensure a professional-quality installation.

Cutting the Fiberglass

The first step in puncturing your fiberglass isn’t to cut—it’s to drill. Using a drill, go carefully in the corner you’ve outlined for yourself with a marking pen after your measurements. If you haven’t completed that step already, now’s the time. With these drill-holes in place, you’ll have a much better idea of what the hole through your fiberglass will ultimately look like.

Don your safety goggles. Using a jigsaw fitted with a metal-cutting blade—and not a blade designed for wood use—it’s time to cut between the holes. Keep in mind that if you have particularly thin fiberglass, it could flex to a wide degree, so be careful here. You only get to cut the first time once, so precision and extra caution are warranted.

Once you have the first line through the fiberglass, repeat the process between the other holes. Remember to venture on the side of cutting inside the holes, as you can always expand the hole to suit your specific measurements.

Now, clear out any debris. You can use a file to smooth out the edges. You should now have a hole of the appropriate size in your fiberglass. Complete the instructions of the item you wanted to install and—voila—you’ve made an addition to your boat.

Maintain Your Boat’s Fiberglass

Dealing with fiberglass is intimidating for a lot of first-time boat owners, but if you understand how it’s different than wood, you’ll stand a much greater chance of success. And don’t forget to adequately prepare your fiberglass in advance with the appropriate boat cleaners from BoatLIFE.

Life Industries Corporation
4060 Bridge View Drive
N. Charleston, SC 29405
United States of America

toll free: (800) 382-9706
local: (843) 566-1225
fax: (843) 566-1275


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