Posted by Eric Frasco on March 25, 2002 at 14:32:12:
In Reply to: Old air posted by Bob on March 24, 2002 at 13:36:33:
Bob:
Where did you get the tank filled last? Did you do any boat diving and get fills from the boat's compressor since you bought the tank?
Under normal conditions, the air that is pumped into your tank should be free of impurities and moisture, but this is not always the case - especially on boats, for more reasons than I have time to go into in this posting.
Also, when was the compressor you got your fill from last serviced? Sometimes the shops get a little late in their maintenance routine and forget to change the filters on time (for example, how often do you take your car in for an oil change exactly every 3000 miles?).
As Kendall said, you should be able to top it off and go for it, but there are too many factors out of your control. So as Ken K. said, for peace of mind get a fresh fill.
Finally, if you still haven't made up your mind, then do this: put your reg on your tank, and take a couple of breaths of air from the tank. Then take a couple breaths (from the surrounding air, not the reg) then another few breaths from the reg. If you notice any difference in taste between the air around you and the air in your tank, then drain the tank and get another fill (of course, if you live close to a freeway and it is rush hour, the air in your tank may taste BETTER than the air around you!).
-Eric-