The hand wire splicing technique has been around for awhile, so I cannot take credit for inventing nor perfecting it.

Poor electrical connections cause heat. The longer the current flows through the connection, the hotter the connection will get. This in turn increases the resistance even more. The problem with a butt connector is that is one surface area. Since electricity flows “on” the wire strands rather than “in” them, this doesn’t make functional use of all of their surface areas. Using this hand splice method will allow for the wire to transfer more of its electrical effort than using a butt connector and will produce less heat.

Step 1: Strip back about 3/4 of an inch of insulation from both wires. Add a section of shrink tubing onto the wire. (Don’t forget this step… or you’ll regret it after you’ve finished the splice.) Divide the bare strands into two equal sections and form them into a “Y”.

Step 2: Holding a wire in each hand, take the “Y” and interlock the two wires together. But, leave room between the two “Y”’s large enough for the outer insulation from the “none” strip section of wire to easily pass through. Lay the “Y” sections down along the wire without bending them backward, straight and even with the wire. Find the edge of the gap you left in the “Y”’s (That thickness measurement of the outside insulation, just about halfway between the two wires).

Step 3: Using one hand, pinch down on that spot while taking the legs of the “Y” from the same side and stand them straight up 90 degrees from the splice. Now, using your other hand, with firm finger pressure rotate the two legs of the “Y” around the splice towards the opposite wire. If done correctly, the spacing you left between the two “Y”s will actually lie down and end up right where the insulation begins. Also, as you pinch and roll the bare wire, keep it snug as possible. You want to end up with it no larger than the outside diameter of the insulated sections.

Step 4: Now switch procedures from the right hand to the left and and stand the other set of “Y” legs 90 degrees and do the same crimp and turn all the way to the othe
r insulated section of wire.
When soldering, be sure not to soak the splice with solder. The solder is only to aide in holding the splice in place so it won’t unravel, and the shrink tubing
is for overall weather protection, and to shield the bare wire.Once you’ve got the hang of it, you’ll find that the splice is extremely strong even without solder or shrink tubing.

Done right, the splice should have plenty of mech
anical hold without soldering. For battery cable, 4 gauge and larger, crimp or soldered connectors are still the best method. But for the average gauge wire, this method works extremely well.
Give it a try, and when you’ve mastered the technique, try it on your friends and see how much effort it takes them to pull it apart, even without soldering it.