Lighter "Freezing"
 

Lighter "freezing" is putting a lighter in the freezer for about 30 minutes before filling, believe this is a part of the instructions for filling a Dupont and a few other lighters.

I know it works, but does anyone know the "why?" behind it?

Re: Lighter "Freezing"
 

Butane is only a liquid under pressure or colder temperatures. When a lighter is empty there isn't enough pressure in the tank to maintain the butane in liquid form so it changes to gas while filling and causes it to be "full" sooner. Freezing helps to keep the butane liquid while filling and allows a more complete fill.:2

Re: Lighter "Freezing"
 

:tu
That was so simple I feel dumb for asking!