There is a conversation about this going on in Another Place
snipped-for-privacy@oldengine.org
and it being quiet here, I thought I'd kick off a new thread. The thread started by discussing the use of old Propane bottles and refrigerant tanks as cooling hoppers et al.
I've come across a few ways of stopping your tank from going BANG when cutting or welding.
In the Isle of Man in the 1970's there was a very skilled aluminium welder who could weld up your tank while you waited. If you went for the expensive option, he'd throw a handful of dry ice (frozen CO2 which he kept in a big vacuum flask) into the tank first. The cheap way was to flash it off, done with a lighted taper on the end of a long stick. He always had plenty of space around him in an otherwise crowded paddock ;o)) Usually, there would just be a faint pop, but on a warm day, you might get a whoof of flame out of the petrol cap. Once I saw the tank converted into a roughly flattened sheet of aluminium that did not fly too badly at all. They stopped him doing it after that.
My mate Reg Lewis that removed dents from steel motorcycle tanks in the
1980's used to tip a bottle of AirWick into the tank before he cut the bottom out never once had any trouble.I've always filled them with water overnight and then swilled them out with a drop of washing up fluid (tepol) given a hearty shake and drained out.I work on the principal that if it doesn't smell of petrol, there isn't enough to explode.
I'd fight shy of taking an angle grinder to a Propane cylinder without some kind of precautions, I must say. Any ideas, anyone?