A portable conveyor belt splicing apparatus is provided that includes an upper press assembly and a lower press assembly which include, respectively, upper and lower platen assemblies. The upper and lower press assemblies may each include a forced air cooling system for rapidly cooling platens of the platen assemblies. The upper and lower press assemblies may include insulating assemblies with resilient members that support the upper and lower press assemblies. The resilient members provide structural support and insulate the platens from the frame which reduces the power required to heat the platens. In one form, the apparatus includes a power supply circuit that can alternate between providing power to upper and lower heaters in response to the apparatus being connected to different types of standard power supplies. Further, the power supply circuit permits the use of a single recipe for a particular belt irrespective of the type of power supply.