Learning About and Caring for Your Fiberglass Cast

What Is A Fiberglass Cast?

A fiberglass cast is a plastic or rubber mold made from resin. The resin used for casting is usually polyester (PET) resins, but other types are available such as acrylic, urethane, etc. Some people prefer using polyurethane (PU), which is stronger than PET and less likely to crack. However, PU is not recommended for use with children under 3 years old due to its strong odor.

Fiberglass casts are commonly used in many industries including automotive, aerospace, medical devices, construction equipment and much more. They have been used since the early 1900’s when they were first developed. Today they continue to be widely used in many fields.

Why Do People Care About Fiberglass Cast?

People care about fiberglass casts because they are very durable and can last for decades if cared for properly. Fiberglass casts can be molded into almost any shape, but their most common uses include:

Molds for making toys, dolls, figurines and other small items. These molds are often called “toy molds” or “child’s play” molds.

For making car parts, especially engines and transmissions.

The shells for break-dancing and flash-mobs.

Fiberglass casts are also used in the medical industry for making casts that will not react with human skin or release dangerous chemicals into the human body.

What Are The Advantages Of Using A Fiberglass Cast?

Fiberglass casts have many significant advantages over other types of casts. Some of these advantages include:

They dry quickly.

They are easy to clean and care for.

They come in a wide variety of colors (more than 20 standard colors).

They can be easily repaired if damaged.

They are lighter, softer and less restrictive than plaster.

They do not have any unpleasant odor.

For the medical industry, they do not contain the dangerous chemicals that can cause skin irritation or allergic reactions.

What Are Some Drawbacks To Using A Fiberglass Cast?

Fiberglass casts do have some drawbacks that should be mentioned. Even though they are strong and durable, the resin tends to be more brittle than plaster. This means they are best suited for short-term purpose, such as immobilizing a broken bone while it heals. They should not be used in place of a long-term solution such as an ankle brace or wrist support.

They are also more difficult to find in specialty colors, such as pink or blue.

How Are Fiberglass Casts Made?

Fiberglass casts are made by mixing a dry resin with a liquid catalyst in a plastic bag and then adding the appropriate amount of softening agent. As the ingredients are mixed together they create a chemical reaction that results in expanding the product. The length of time it takes for the mixture to expand depends on the thickness. For example, a 1-inch-thick cast will take about 2 hours to fully expand, whereas a 1/4-inch-thick cast will take only 30 minutes to expand.

The mixture is then poured into a mold of the appropriate shape and size. The liquid is allowed to dry until it has solidified. Once dry, the cast can be removed from the mold.

How Are They Used?

Sources & references used in this article:

Parent satisfaction comparing two bandage materials used during serial casting in infants by HS Coss, WL Hennrikus – Foot & ankle international, 1996 – journals.sagepub.com

A randomized trial of two irremovable off-loading devices in the management of plantar neuropathic diabetic foot ulcers by IA Katz, A Harlan, B Miranda-Palma… – … care, 2005 – Am Diabetes Assoc

Postoperative Spica Cast Care by PL Horn, E Badowski – Orthopaedic Nursing, 2015 – ingentaconnect.com

New synthetic casts: what nurses need to know by PL Lane, MM Lee – Orthopaedic Nursing, 1982 – journals.lww.com