Abstract: A method of passivating the interior surface of a gas storage vessel to protect the surface against corrosion. The interior surface of the vessel is first dehydrated and then evacuated. A silicon hydride gas is introduced into the vessel. The vessel and silicon hydride gas contained therein are heated and pressurized to decompose the gase. A layer of silicon is deposited on the interior surface of the vessel. The duration of the silicon depositing step is controlled to prevent the formation of silicon dust in the vessel. The vessel is then purged with an inert gas to remove the silicon hydride gas. The vessel is cycled through the silicon depositing step until the entire interior surface of the vessel is covered with a layer of silicon. The vessel is then evacuated and cooled to room temperature.