Can welder is frequently used to join dissimilar materials, such as titanium or stainless steel to carbon steel in petrochemical pressure containers or aluminium to carbon steel in ship hulls. Precision welding methods like plasma arc welding are frequently used in aerospace situations where the metal thickness is less than 0.015 inches. An air seal or motor blade would be two examples of such an application. Ionizing gases inside the arc are used to generate heat in can welder, which uses a method that is very similar to TIG welding but with a recessed electrode. The typical gas mixture is argon + 2 to 5% hydrogen for the shielding gas and argon for the plasma gas.