is a natural high moleculr weight linear polysaccharide functioning as a hydrophilic colloid to maintain the micron particles of graphite in suspension and contribute to the penetrating of the coating as described hereinbefore effective coatings for the refractory tiles and runners may be formed with colloidal graphite in amounts between 5 to 25 by weight between 34 to 75 by weight of a solution of water and sodium silicate wherein the water is present at about 60 of the solution between about 2 to 10 concentrated hydrochloric acid of a 90 purity weight between about 33 to 75 of a solution of water acid carboxy vinyl polymer resin wherein the resin is present in amounts between 1 to 10 of the solution by weight and between about 15 to 20 water by weight those skilled in the art will observe that the liquid carriers described herein comprise an effective wetting agent which contributes to the ability of the particles of colloidal graphite to penetrate the refractory material of the tiles and runners and form a smooth dry coating on the penetrated surface it is believed that the penetrating ability of the liquid carrier and graphite suspension is improved by the addition of from 1 to 10 parts by weight of micron silicon particles it will occur to those skilled in the art that the thickness of the coating material forming the lining of the runner 15 and tile 23 as seen in fig2 and 3 of the drawings has been somewhat exaggerated and it will occur to those skilled in the art that the thickness of the coating formed after the penetration of the graphite material into the refractory may be varied by applying successive coatings of the graphite suspension.