Solar Thermal Wiring

What type of splice should I use when joining sensor cables to system wiring?

What type of splice should I use when joining sensor cables to system wiring? Do not use wire nuts or connectors. Solder all wire connections, and cover them with shrink wrap tubing. Additionally, since most shrink wrap tubing is not rated as high temp or UV resistant, make sure that those connections are tucked inside UV sheathing, but outside the...