Carbon Fiber 101
By Jason Helferich
Carbon Fiber: What exactly is it??

January 2005

Who out there has heard of carbon fiber? Do you even know what it is? It has become apparent to me over the past few months that almost everyone in the sport compact scene is aware of carbon fiber as it explodes in popularity. It is being used to manufacture everything from the popular hoods to even fenders and interior pieces now. But another thing that became apparent is that although many enthusiasts are aware of it, very few actually know what it is. Well in this month’s column we will discuss where carbon fiber came from, the properties of the material, and how it is used.

Carbon fiber has been around for over fifty years with its earliest history in the aerospace and military industries. It was normally reserved to these industries as the costs of manufacturing carbon fiber were sky high, and cost consideration is low in these two industries. Only in recent years has production of carbon fiber climbed, therefore lowering the price and making its use more widespread.

Carbon fiber can be produced in one of two ways. These are “wet” lay-up and pre-impregnated lay-up processes. The “wet” process has been used since the beginning of composites. It creates molded shapes from glass or carbon fiber and resin. Do-it-yourselfers use this practice extensively as it is the least labor intensive and expensive money wise. When manufactured in the “wet” lay-up, dry fibers are laid into a mold and resin is poured onto them. The resin is then brushed over the fibers in a relatively uncontrolled manner. Resin is added in layers and layers until the desired thickness is achieved. If this process is not performed correctly the fibers can become saturated with resin which causes added weight, and reduced strength and stiffness. This method can also create inconsistent products as certain areas are saturated and others are not thick enough.

Pre-impregnated lay-up has been refined over the past 20 years to create better products with more predictable results. In this method the fibers are pre-impregnated