<<I'm getting ready to paint my airplane and will be draining the fuel tanks
and removing the wings.  Does anyone have specific recommendations for
venting the tanks thoroughly so that the potential for exploding the wings
is eliminated?>>
<<This may sound really silly but if you were going to do this kind of work
on a non metal airplane wouldn't it be prudent to drain the fuel and leave
the caps off to vent out the fumes.>>

Here's what I usually do:  After draining the fuel I add a couple of gallons
of kerosene.  The kerosene dissolves the remaining gasoline pretty well and
a couple of gallons, especially if you can slosh the tank (easier if the
wing is off..) will get to all the spots gasoline could remain.  Then drain
the kerosene.  Leave the cap off and let it sit at least overnight.  Sniff
in the filler neck - if you don't smell gasoline there isn't enough to cause
a problem-you hope.  The idea of introducing nitrogen (or argon, they both
have the same effect) is okay if you have the gas available, but how do you
know you added enough to get rid of enough oxygen?  Air blowing through a
vacuum cleaner hose seems to be a really good source of electrostatic charge
so I would be hesitant to put a hose like that into a tank.  However, most
of the static charge buildup while vacuuming is probably from the dust
entrained in the air, so maybe clean air isn't as bad.  I wouldn't want to
test that theory on a fuel tank, but in any event I would blow fresh air in,
not suck vapor out because of the reasons explained by others.  And besides
all that, doing any of this on a really dry day is scary.  Humidity helps
more than almost anything else to eliminate ESD events.

Gary Casey
ES kit, no fuel, no worries