This three inch copper coil is made up of two different coils. The outside one is made with 1/4in copper tube coiled to fit inside of a 3 in copper tower. The inner coil is made of 3/16in tube coiled in a double helix for maximum surface area.
These coils are soldered into a 3 in cap with quarter inch brass compression fittings soldered onto the ends.
All made in shop!