If your old porcelain sink has lost its shine and has become dull, you can re-glaze it like you would a bathtub and restore it to its original shine. You need to cover all the metal and aluminum fittings connected to the sink with painter’s tape before you start. You then apply hydrofluoric acid, which is an etching solution, to the surface of the sink. Proceed by spraying a healthy amount of primer on the sink to coat and protect it and prepare it for the glaze. After this, spray on paint specifically made for porcelain resurfacing. This can be bought at your local paint, hardware or home improvement store. All these steps should be done when re-glazing your porcelain sink.