Jerome Yuzyk wrote:
> In article <e28c444.36f961dd(at)aol.com>, TIGEROOTES(at)aol.com wrote:
> > ...or you could throw a lit match in...
>
> Al that would ignite would be the dust that's collected in it over the
> last year...
Jerome:
Don't assume this, since I had a farmer friend who was killed cutting the
top out of a barrel that had water running through it for 5 years! The
pressed steel seams on tanks of various types can trap enough gasoline to
form an explosive mixture with air when heated (3-5% vapor is all it
takes).
Also, I served part of my apprenticeship in a tank shop and the only way we
would weld or cut on any tank was to steam it for 24 hours and keep the
steam running through it while we were working on it. An alternative for
quick repair was to use a semi -inert gas (nitrogen or CO2) after a shorter
period of steaming This all takes speciallized equipment (steam generators
and regulators for applying gas etc.). Most dents we used to pull unless we
could see that they would pop easily. We also used pressure to remove dents
but would seldom exceed a few psi and always used a regulator to avoid
damaging or blowing up the tank . We also used a resistance (spot) welder to
weld studs to the exterior of tanks (similar to Jarrod's method) and then
pull the dent.
Filling the tank with water will limit the size of the explosion that may
occur, but will make it impossible to weld, braze, or solder with a torch,
unless there is air (and vapor) under the area you are working on (I assume
Jarrod did his work with the traditional soldering copper which is fairly
safe). Exhaust gas, while fairly inert, can and has blown up many tanks and
some people due to hot carbon particles being carried into the tank.
If you decide to use the pressure method, calculate the suface area of your
tank, use a good regulator,low pressure, and allow the air to flow, so that
you can increase pressure very gradually and carefully. ( I once saw a
5'diameter bulkhead blast through a concrete block wall and continue flying
for another hundred yards after a "creeping" regulator hadbeen left
unattended).
This is probably much more than you (or anyone) really wanted to know, but
I'd hate to see anyone on this list become a statistic!
Ron Tebo
This archive was generated by hypermail 2b30 : Tue Sep 05 2000 - 10:40:48 CDT