Free CO2 for MIG welding / robot testing

Hi guys I may be teaching granny to suck eggs here but I thought Id post this in case some of you hadnt thought of it.
Contact your local fire extinguisher dealer / servicer (small businesses preferably) and ask if you can have any old CO2 (out of test date) extiguishers, explain what you need them for (mig welding / robot testing etc).
My local bloke gets a small skip in about once a year or more and fills it! Most are the water type but there are always lots of CO2 and most of them are full!
I havnt bought CO2 for my mig for 5 years!
From one skip diver to (I suspect!) many others!

Youre a mine of information Mike! :)

I have done this many times. Often the dealers are more than happy to give you as many bottles as you can fit in you car :D

Thanks Kane, when your as old as me (and as tight!) you pick up a few tricks.
Talking of skip diving, some very useful stuff can be had from engineering companies waste!
Mike.