We have been using Scotch Tape (This might be called TESA in Europe). Depending on how clean a splice you need, you can arrange the two ends of the tape with their back side on the scotch tape and trim off the remaining scotch tape. A diagonal cut is best. The alignment is a little tricky, but it gives you a splice that will work for a while.... We even fixed broken VHS tapes this way..... In the past we had a rig and some special tape..... long gone.... Otmar