An inert gas chamber for use in continuously curing oxygen sensitive coating compositions by the application of radiation, employs a jet of inert gas to displace the air boundary layer on the coated substrate as the coated substrate moves into the chamber. The coated substrate is also blanketed with inert gas and subjected to the radiation. The use of inert gas to cool the window of the electron beam accelerator may be used in the chamber, thus avoiding ozone-based pollution.
