A ladle car opening is closed during the period between pouring and subsequent refilling of the car with molten metal by a closure plug comprised of an open wire mesh support and a lining of fibrous insulating material attached thereto. The plug has a tapered configuration providing for the outer end thereof to be larger than the opening into the ladle car, and the wire mesh support and lining provides for the plug to be flexible so as to conform to the peripheral contour of the opening and to engage a peripheral outer edge of the opening to close the opening and retain the plug therein.
