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How to Fiberglass Like a Pro

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Liam is a long-time writer who enjoys learning about and sharing information about health, space, and material sciences.

Fiber bonded with plastic resin has a long, long history. As with many manufacturing techniques, fiber-reinforced plastic came into wide use in the military. Part of the reason for this is the ease with which objects can be created by combining these two materials. It is also quite strong when compared with an equal weight of steel. Fiber-reinforced plastics can be as much as six times stronger than steel at an equal weight.

But the real attraction here is objects made with this material require no high temperatures, a modest collection of tools, and best of all, very little prior experience. In fact, if you've built a sandwich and painted with a brush, you know most of what you need to know about fiber-glassing.

What Is Fiberglass?

Fiberglass, as a term, is really a misnomer. Glass fiber is one of the many materials that can be used along with resin (plastic) to create a strong and light composite structure. Those materials include glass-fiber (of course), cloth (cotton or man-made), carbon-fiber, non-woven glass or carbon mat, coir (a coconut fiber), modal (beech tree fiber), bamboo, and even hemp fiber.

In truth, what most people call fiberglass is properly referred to as Fiber Reinforced Plastic (FRP). It is a composite material, much like Carbon Fiber Reinforced Plastic (CFRP) so popular today, but FRP predates carbon fiber by at least seventy years.

One of the earliest uses of FRP was by the United States military in making helmet liners. (see picture at lower right for a World War II liner)

After the war, returning GIs began experimenting with the material in the form of car bodies and boat hulls. Sailboats were some of the first items built with this material and a few years later powered watercraft. Because so little was known about the strength of FRP in those years, most of those items were "overbuilt." Boat hulls and car bodies made in the '50s and '60s are still around today, almost indestructible in their strength.

Ideal Hobby Material

In many ways, it is an ideal hobbyist material. With a bit of patience, it is fairly easy to use with most of your effort going into preparation if not actual creation of the item. No special tools are required. In fact, I recommend using old food containers to mix the resin in and purchasing or using cheap bristle paintbrushes, plastic trowels, and/or wooden dowel for applying the resin.