How much gas...

I think you have that arse about face. You want the cylinder and gas to be cold. Then bring them into somewhere warm and wet to see where the condensation forms. Condensation only forms on surafces that are "cold", ie below the dew point of the enviroment they are in.

I was thinking along the lines of just opening the HP valve letting some of the gas boil off and seeing were the frost formed. This would only work on propane (orange) bottles not butane (blue) though.

weigh it. the weight of the empty cylinder is stamped on it so just subtract that and you have the gas left.

In message , "Mungo \"Two Sheds\" Toadfoot" writes

Just enough to get halfway through your next BBQ

can't you get some idea from shaking it and seeing how much flops around?

I was just about to suggest that

is it 15kg blue calor ?

If so, I have some spare empty containers

BTW, I pay £18 / container

You could put a jumper on and get someone to do impressions of a coffee maker - they always remind me of that with their hissy horrid sound.

It's orange. I bought it from a boot fair/sale about 10 years ago!

Si

ISTR a plastic strip you can stick on that changes colour with temperature.

Try a caravan shop.

Not having open air heating.

How else can one dine al fresco when the weather is inclement?

Slosh it as others have said and read Dennis@home's comments.

If it sloshes, there's enough for a domestic BBQ.

Last week, I used 2 of my 20kg? bottles to fuel 2 Burcos at a public event. On entering the field, I was asked why didn't you bring a spare. "We've enough" which was right. Either bottle will now keep me in for the season or perhaps years on domestic BBQs depending on our weather!

Maybe the gas is filled in layers, with the smelliest at the bottom precisely in order to warn you to order more.

MM

It was quite popular in the 1930s when special open-air schools and sanatoria were run.

Owain

Tell the butler to move the picnic further south.

Owain

Opps ... You're right... Wrong way round!

Slatts

I could well be wrong, but I thought they were not heated. At all.

"Exposure to cooling air a powerful therapeutic agent."

That's what I thought too.

Mary