The present disclosure is directed to a method of producing a surge arrestor module, comprising the acts of (i) providing a plurality of MOV blocks arranged in a stack, (ii) applying an epoxy-reinforced structural layer to an outer surface of the stack, (iii) after the applying, inserting the stack into a flexible bladder, and (iv) curing the epoxy-reinforced structural layer with elevated temperatures while the flexible bladder applies radially aligned pressure to the stack and a tool applies axially aligned pressure to the stack. The present disclosure also includes an apparatus for performing the methods described herein. The apparatus includes an outer case structure and a flexible bladder that fits within the outer case structure. A hollow inner region of the outer case structure is pressurized to force the flexible bladder against the surge arrestor module as the surge arrestor module is curing.