In past years I would and still do solder wiring. My shop teacher in high school tought me to use what is called a (western union splice) Its simple to do but difficult to describe without a picture. Maybe you can look it up on the web. Oh and I use heat shrink. I found heat shrink not only in all colors but also in any length and diam. you want at an electrical supply.

I didn't do it, no one saw me do it, you can't prove anything! "Bart Simpson"