The present invention describes a method for curing polymers and polymer composites with X-rays generated by the bremsstrahlung effect, using a high power, high energy electron beam. The process generates X-rays with sufficient throughput and penetration for commercial use. The present invention employs high power, high energy electron beams to create the X-rays. The beams are typically run at energies ranging from 1 MeV to 10 MeV, preferably from 3 MeV to 10 MeV, and more preferably from 5 MeV to 7 MeV. The beams typically have powers ranging from 30 kW or higher, preferably 80 kW or higher, more preferably 100 kW of higher, and ideally at least 200 kW. Suitable polymers and polymer composites include, but are not limited to, polymeric molding materials, fiber reinforced molding materials, reactive monomer impregnated wood, similar and dissimilar materials bonded through adhesives.