Hehehe. That's alright - I knew what ya meant...

They really do rust up pretty fast, those other types. Even the *chrome* extinguishers (which you may have been thinking about) are bad like that.

I pulled aside a Helium tank years ago for some future project, but the more I think about it, the less useful the tank seems. It's about 4' in height, but it weighs a freakin' ton!