Christopher Tidy wrote:
Hi Grant,

I spent a while yesterday looking at people's project pages and came
across your propane tank degassing page. I've considered reusing propane
tanks on several occasions, but had a different method of degassing in
mind. Before I get to the details I should point out that our propane
tanks (in the UK) might be a little different from yours, and that I'm
talking about the largest (47 kg) variety.

Take the valve(s) out and turn it over for a day. The gas will run out,
it's considerably heavier than air. I've cut dozens of LP tanks, from
20lb to 1000gal. without problem, except for a couple that flashed
because I didn't let them drain long enough.

When cutting sealed containers I always make a point to start as far
from the hole as possible. If it does flash at least the fire isn't
between the not-yet burned mixture and the hole.

John