I wrap my bottle in a duvet, with a couple of picnic freezer blocks and leave 'em in the back of the car for 1/2 an hour before I set off for the dive shop.
That means the cylinder is at about 5 celcius when I arrive, ready for a full fill, without the cylinder ending up warm and under filled.
The laws of physics are always useful.
[QUOTE=krisko;7302306
there are some quite good Chinese compressors out there for 2-300quid, and no more worries about the need of having periodic tests on cylinders etc.[/QUOTE]
Chinese Compressors and untested Cylinders, now that seems like a recipe for a long life