The present invention is directed to disposable composite downhole tool formed of a resin-coated fiber. The fiber is formed of a degradable polymer, such as a poly(lactide) or polyanhydride. The resin is formed of the same degradable polymer as the fiber. It chemically bonds to the fiber, thereby making a strong rigid structure once cured. The fiber may be formed into a fabric before being coated with the resin. Alternatively, the fiber is formed of a non-biodegradable material.