Out of curiosity what do you pay for a J of Helium? Does that come in different grades too? In the past I have used CO2 for welding and also what the call 'Tavern Gas' which is food grade CO2 to make fizzy drinks with. There was no discernable difference to weld with. We used whatever was cheaper. Is this just one of those Heinz / supermarket things where the products are all the same? Out of curiosity since many dive shops seel these gases by the litre, how many litres are there in a J? That's how many does it hold not how big is it...
