"Rob" wrote in message
...
Hi folks

I have 300 gallon tank formerly filled with gas oil / 35 sec heating oil /
medium diesel (not sure
of the U.S. terminology). The only way I can remove it is by first cutting
it
up. Any suggestions / comments
so as to do this safely?

Regards
Rob


following this thread with interest.
i had heard of someone who hand dug around a 1000 gallon tank, was in the
ground since the 70's. was too heavy to pick up with a compact tractor so
he plugged the tank and filled the trench with water and floated the tank up
and rolled it out of the trench, he felt clever and was proud. after
getting it out he cut a 2' x 2' square hole in one end with a bosch jigsaw
and scooped out the inch or so (on the low end of the tank) of sludge. he
said he was amazed there was only *slight* pitting at the bottom of the tank
so it was obvious there couldn't've been any oil leaking at all, the tank
was in good/excellent condition but the fear of a leak precipitated it's
removal. the empty pit was entirely oil free, thank goodness. tank was
made of (surprisingly) 3/16" thick plate. cut it up the rest of the way
with a plasma cutter. no fire/smoke problem at all.
second tank he cut up was dragged out of the woods from an abandoned
farmer's road. 275 gal. tank had obviously been sitting there for like
15/20 years. actually had tiny holes rusted through in a couple spots.
sniffing inside BARELY smelled at all of oil. figured it was safe to start
cutting with the plasma and forego the hassle of starting with the
sawzall/jigsaw. this person wasn't aware of the dry ice trick and was too
cheap to go get a bottle of CO2, figured he'd chance it. figured whatever
traces of fuel oil vapors that remained weren't volatile enough to ignite.
there were mice nests inside the tank and when plasma cutting the tank the
mouse nests started to smoke. was kinda scary because the smoke was like a
funky green or brown color. he was worried there might be enough volatile
material in the funky colored smoke to ignite, and there was great fear it
might ignite explosively. scariest part was when he was spraying water into
the open bung holes of the tank it actually seemed if the smoke increased!
it didn't start to subside for a WHILE. there was a increasing fear that
there might've been something in the tank other than old evaporated fuel
oil. he attests it was really quite terrifying. i think he was very lucky
that time(!). after cutting this tank had no sludge but organic (weeds,
grass, straw) mouse nest materials (and two oil mummified mice). recently
there was wondering if it would be possible to get a small (80cu.ft) tank of
CO2 and empty the CO2 gas into a 275 gal. fuel oil tank to safely cut it up.
now there is wondering how many pounds of dry ice would be enough to make
enough CO2 gas to fill a 275 oil tank to safely cut it up. this person
doesn't have the electronic sniffer tool mentioned in a post to this thread.
there was something recently on-line about a local tank removal company
writing they "inert" an 1000 gallon tank and then there were still photos of
an access hole being cut with a demolition saw w/ abrasive wheel.
the person cut the tank in half, lengthwise, and then trimmed the two halves
so they could be used as a large "tray" or "scoop" on the forks of a
"forklift" thingy on the three point hitch on back of a compact farm
tractor. turns out they're really quite useful for hauling rocks (full
bucket in front and a "full" tray on the rear). and hauling firewood from
the area where his log splitter is to the woodshed, a 275 gal. fuel oil tank
cut lengthwise holds more than the front bucket of a compact farm tractor,
easier, less trips. i think the steel "tray" is possibly even lighter than
if it were to be built of wood.