Because of the rainwater run-off into the fruit trees and also because it isn't as effective now due to chemical prohibition, we don't use weedkiller. Instead we have bought a large weed burner which is quite effective, although needs to be used often. Problem is it needs 2.5 bar pressure which it has initially, but after a short while the 13Kg bottle chills off (condensation on it) and the pressure drops. Then the flame isn't hot enough and it has to be left to warm up again. I've been using it with over half full bottles and putting the remainder aside for the cooker hob, which works better, but used it this cold morning and it was useless in seconds, even with a full bottle. At the moment it runs on Butane, as does the cooker hob, but the instructions say I could use Propane with the same regulator (we have different fittings to the UK).
I think Propane burns hotter? But is it less affected by the cold or chilling from evaporation- does anyone know? I don't want to stock more gas bottles unless I will get a practical benefit from that.