Here's a link to a new product out there. I would have sent this to Larry, but it would have been hard to include effectively without the video. It's a butt splice that includes low temp solder within and a sealant that keeps moisture out
I couldn't guess how many hours I spent butt-connecting wires to mate my 64 Chevelle harness to 85 Camaro steering column, aftermarket gauges, HEI, electric fans, actuators for my tilt front, etc. These would have been a huge time saver.
Sorry guys, I’m a little delinquent reporting back on the butt splices, but here goes. I ordered a kit from Amazon similar to the one Stan posted. I suspect it may be of inferior quality than the ones available from Summit, but it was less expensive and arrived the next day on the brown truck. The kit contained 105 splices for wire size’s ranging from AWG 10 through 26 and cost about $12.00 A buddy and I tried several splices independently from each other with 14/16 AWG using several different heat sources ranging from torches to cigarette lighters and then compared notes. We learned there is a fine line between just enough heat and to much heat. On several attempts by the time I got the solder to melt the wire would be protruding through the side of the splice or the heat shrink itself would began to bubble and deform. My buddy was having the same problem on the other side of the table. Not enough heat and the solder would appear to melt but the splice would pull apart with minimal effort. After a half dozen or so try's we both seemed to master the required technique, so they will work, it just takes a little effort to get past the learning curve. The splice itself is not attractive, certainly not OEM looking. I wouldn't use it were it would show and regardless I would go over it with regular heat shrink. I think I’ll stick with the old J hook twist soldered and double heat shrink.