SpudFiles

hey, does anyone know if after combustion there is still propane in the chamber hence the need to ventilate using a fan to get knew oxygen in the chamber?[/list]

With a correct mix there should be little, if any propane or oxygen left in the chamber. Both are used up in a combustion reaction to make carbon dioxide, water, and heat.

To answer your question, yes it is necessary to vent the chamber between shots to get fresh oxygen into the chamber.

The product is co2 and water, and both of those would hamper the combustibility of the mix you add afterwards