Because I never seem to have more then one or two gassers set up at any given time I sort of do the same thing as John. I just mix one gallon at a time so I use it up and mix up a fresh gallon in another can before I run out. I use one cheap Magnum hand pump for my gassers. Just transfer the pump and lid from can to can. Going electric is fine but unless I have several planes burning gas I wouldn't bother. This from a man that doesn't like hand pumping at all. I do use electric for my glow powered planes but I usually have two or three of them with me at the field and only one gasser.