use in this invention preferably is in the form of a powder having a particle size of from 4 to 7 u03bcm silicon hexaboride is preferred and an exemplary silicon hexaboride is 98 silicon hexaboride sib 6 200 mesh from cerac corporation milwaukee wis an exemplary fiber coating contains sio 2 powder in an amount of from 23 0 to 44 0 wt and preferably from 29 0 to 39 0 wt colloidal sio 2 in an amount of from 25 0 to 45 0 wt and preferably from 29 0 to 40 0 wt silicon hexaboride in an amount of from 0 5 to 4 5 wt and preferably from 1 5 to 3 5 wt water in an amount of from 19 0 to 39 0 wt and preferably from 23 0 to 35 0 wt the content of each component is given in terms of the total weight of the protective coating the protective coating 15 is prepared by first forming a slurry of the components of the protective coating and then ball milling the slurry to provide a uniform solid dispersion the slurry is then placed in an appropriate storage container e g pint or quart plastic bottle and rotated on a kendall or equivalent mixer until just prior to application onto the fabric 14 the protective ceramic coating 15 is applied to the ceramic fabric 14 preferably by use of a spray gun the coated ceramic material is preferably uniformly coated such that all filaments yarns and threads of the ceramic material are completely covered a dry.