There is provided a ceramic coating of zirconium diboride, silicon carbide, zirconium phosphate and silicon phosphate, that protects carbon-based materials from oxidation in high temperature oxidizing environments. The coating is applied at room temperature with a brush, roller, squeegee, doctor blade, spray gun, etc., and cured at room temperature. The cured material forms a hard, protective ceramic shell. The coating can be applied to various carbon based materials including, but not limited to, amorphous carbon foam, graphitic foam, monolithic graphite, and carbon-carbon composites. Alternative compositions of the coating can be the partial or complete substitution of hafnium diboride for zirconium diboride. Additional modifications of the coating can be accomplished by partial substitution of the borides or silicides of Ti, Ta, Cr, Nb, Ti, V, Re, for zirconium diboride.