Chemical plasticisation

It is a method of temporary wood softening using chemicals, mainly ammonia. It is a more effective plasticising method than steaming, however, the chemical is dangerous. Anhydrous ammonia can be either gaseous or liquefied by pressure (0.846 MPa at 20°C) or low temperature (-33.4°C). Wood swells in ammonia and becomes very pliable. When this chemical evaporates, the wood becomes rigid again. Compared to steam bending, the ammonia plasticisation method results in bends that are more stable in wet conditions.