Abstract: Methods for making an environmental barrier coating using a sintering aid involving: applying a bond coat layer to the ceramic component; combining at least water, a primary transition material selected from a rare earth disilicate, or a doped rare earth disilicate, and at least one slurry sintering aid to produce a transition layer slurry; combining at least water, and a primary outer material selected from a rare earth monosilicate or a doped rare earth monosilicate to produce an outer layer slurry; combining at least water, and a primary compliant material of BSAS or a rare earth doped BSAS to produce a compliant layer slurry; applying at least the transition layer slurry, and any one or more of the outer layer slurry, and the compliant layer slurry to the component; and sintering the component to produce the environmental barrier coating having at least the bond coat layer, a transition layer and any of an outer layer or a compliant layer where a reaction between the primary materials and the slurry sinte