Powder Coating is a type of coating that is applied as a dry powder. The main difference between a liquid paint (spray paint) and a powder coating is that the powder coating does not require a solvent to keep the binder and filler parts in a liquid suspension form. The coating is typically applied electrostatically and is then cured under high heat to allow it to flow and form a thick skin. The powder may be a thermoplastic or a polymer. It is usually used to create a robust smooth finish that is tougher than conventional paint. Coating objects in this way is perfect for household objects and car wheels for example.
The problem comes when combining the powder coating process with an old reclaimed cast iron radiator, due to the individual sections that make up a cast iron radiator having fibre or paper gaskets. When the process of powder coating gets to the curing stage in the oven, the paper gaskets singe and burn. This means when you get your lovely powder coated radiator back home and back on the heating system, there is a very high chance that the burnt or singed gaskets will now leak!
The only sure way to powder coat your reproduction or reclaimed cast iron radiator is to take all the adjoining radiator sections apart, then powder coat and finally rebuild with new gaskets.