After 96 hours there has been a very slight change in the inflation of the balloon. You will note the outline around the quarter can still be seen but the reference circle is about 1/8" smaller in diameter than on day one. If there is an air leak somewhere in the tank it must be extremely slight. So slight, in fact, that it is not likely to show in a soap bubble test. The very slight deflation could also be caused by environmentals or leakage in the actual balloon itself. I have noted that party ballons when inflated and tied off do, in fact, lose pressure over time. I suspect the average party balloon is somewhat porous and bleeds pressure over time. That's my guess and I'm sticking to it until I see blue fuel stains on my tanks.
I think 96 hours is long enough but I plan to leave the balloon attached a few more days just to see the results.
