Summary I got tired of taped up cable joints. they become tacky and the cables short out. I fill the mould with marine grade silicone after joining the wires together. This helps with insulation, and provides some adhesive strength to the joint. You can also use hot glue from a glue gun, probably going to work better. Use a M4 bolt, between 15mm and 20mm long to fasten the 2 sides together. If you can get plastic bolts that is even better, for added safety.