How To Repair Cracked Nylon Gears?

How To Repair Cracked Nylon Gears? Reinforcements. Glass and carbon fiber reinforcements increase the load capacity of plastic parts. Compounded into a thermoplastic resin, these fibers also increase the rigidity, and in the case of crystalline resins, the temperature range. How do you fix a broken gear? How do you weld a broken gear tooth?