Stage two is the encouragement of polymerisation, turning the Styrene-Polyester with which the wood has been saturated into polystyrene.
With the carriage impregnated with styrene-polyester resin, it is then placed into a shielded cell and exposed to a Cobalt 60 radiation source. This acts as a catalyst allowing the Styrene to bond with the reactive parts of the Polyester, forming a strong 3-Dimensional structure that is both rigid and waterproof.
With the water in the wood replaced by polystyrene in this way the carriage will be protected and preserved, however there will be minor physical alterations as a side effect.
Firstly the carriage will suffer a small amount of shrinkage (approximately 7%); and secondly