Dense thin β/β’’-alumina electrolyte films of less than 50 μm thickness were fabricated using vacuum dip-coating on porous substrate tubes. The porous substrate tubes were fabricated using a slip casting method. Fine Na-β/β’’-alumina powder was obtained via traditional solid state reaction processing. It was found that vacuum dip-coating is an effective method for fabricating thin dense layers coated on the porous tube. The mechanical properties of the porous tube, with and without the dense layer, were tested using a C-ring method. The optimized sintering process was also studied.