A method for forming a high temperature coating includes forming a pre-sintered ceramic coating on a ceramic composite substrate. The pre-sintered ceramic coating comprises a plurality of ceramic particles. The method further includes sintering at least a portion of the pre-sintered ceramic coating by heating the portion of the pre-sintered ceramic coating to a sintering temperature of the pre-sintered ceramic coating using one or more non-contact radiative heating elements. The sintering temperature is greater than about 1000 degrees Celsius (° C.).