I was going to call this Instructable emergency tubing connections with string. But I now use this method often, even when not an emergency situation. It works when you need to connect any small flexible hose to copper tubing or metal pipe, and do not have hose clamps or barbed fittings.
Step 1: Materials
Assuming that you already have a rubber or vinyl hose, and a metal tube you need to connect it to, you will need:
String. Best is fine nylon cord, but it just needs to be strong. Several feet (a meter or so) long.
Tools: A knife or scissors.