Red Seal Welding Practice Exam

Propane is the best choice for heating material 6 inches thick or larger because it has a higher calorific value compared to the other options. Acetylene is highly flammable and has a low burning temperature, making it more suitable for welding or cutting but not for heating thicker materials. Butane also has a lower calorific value and can produce less heat compared to propane, making it less efficient for heating thicker materials. Methane has a higher burning temperature but is typically not available in tanks or cylinders like propane, making it less practical for heating purposes. Therefore, propane is the best choice for heating material of this thickness.