The standard radiators are blast-cleaned and given two coat each of Red Oxide Zinc Chrome primer and Enamel finish paint (providing for a total dry film thickness of 70 to 100 micro-meters) on the outside, and one coat of heat-resistant varnish on the inside. Other external primer/finish coatings such as yellow zinc chromate primer, zinc rich primer, micaceous iron oxide primer, epoxy primer/finish, polyurethane finish, spray galvanised etc, can be provided, as required.