A reforming mandrel and a method of use reforming mandrel to reform glass are described. The reforming mandrel comprises an upstream portion, a downstream portion and an at least partially hollow interior. The upstream portion may have an intake inlet for fluid flow. The downstream portion may be axially spaced from the upstream portion. The downstream portion may have a flattened cross-section defined by flattened peripheral portions joined by curved peripheral portions. At least one curved peripheral portion may be made of porous material resistant to a temperature of at least 1000° C. The at least partially hollow interior may communicate with the intake inlet and the porous material.