Quote Originally Posted by wogster View Post
I think also common today are propane or butane, both are heavier then air, not sure whether either gas could separate or contaminate chemistry. Obviously you wouldn't want to smoke around them, but you shouldn't be smoking anyway, especially in the darkroom....
And since propane/butane are used as lighter fuel, they are a lot easer to get in house hold quantities than argon. And BTW: argon is quite expensive, too ...