Any ideas or experience in cutting a heating oil fuel tank in half that i removed from the house? It is the standard 275 (i think) gallon size. It is “empty” – except for some of the sludge in the bottom. I have read some people say that it is safe to cut – other sites claim that the vapors (as one would assume) are dangerous.
Anyone have an idea? Thanks.
Replies
cut them in past w circ saw w metal cutting blade, also sawzall don't know about flash problem w fumes, but do have environmental issue w sludge and sludge-lined tank itself
Frank,
A guy here locally got killed a couple of years ago trying to cut one in half to make a bbq. The vapors in the tank are actually worse than if the tank was full of oil. If you are just trying to get rid of it, see if your local oil supplier has a program to dispose of them. If you want to use it for something, I would suggest somehow getting it totally cleaned out first, then fill it with water while you are cutting it. Even then, it is not something I would try. All it takes is one small spark and ........
Bill Koustenis
Advanced Automotive Machine
Waldorf Md
"A guy here locally got killed a couple of years ago trying to cut one in half to make a bbq" --Was he using a cutting torch?
I'd like to know more of the particulars, like did he try to "rinse" the tank with something first? i've cut four tanks apart and seen sparks land in the puddles and die. Fuel oil itself just isn't volatile enough. Something else had to be there or a breakdown of some kind had to have changed the makeup of it to make for an explosion.
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Pif,
I dont know the particulars, just that it happened and made the paper. If I remember correctly it was a "harry homeowner" backyard type thing. He might not have even drained it, never mind rinse. Either way, I would not recommend it to anyone unless they are absolutely certain that there are no fumes present.Bill Koustenis
Advanced Automotive Machine
Waldorf Md
Maybe I've been lucky and maybe he used something volatile in trying to rinse it out first.
Somebody made the suggestion to fill it with water - maybe soapy water, and then do the cuttiong. Tjhuat sounds like the ultimate in safe to me. A full tank would not have any fumes and the soap or degreaseer would cuyt the oil if any spilled. Then a plasdtic sheet spread under with kitty litter on it could handle any oil that did seep. I'll do some more thinking the next time i undertake this and stillllll want to hear more from any chemists who really know something. Thanks for the heads up.
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I have never done this but seem to remember hearing of tank removal companies throwing dry ice into the tank to displace oxygen.
But then again it may just be the voices in my head.
Purge oxygen with inert gas, nitrogen or co2.
They likely used the dry ice to keep the temps down so no vapors would form. Evidently, it takes 100F to make fuel oil vapors.
This article does give one pause.
http://www.santacruzsentinel.com/archive/2003/July/09/local/stories/01local.htm
I've cut a few of these apart over the years and never had an incident. Can't remember what the ambient temps were, but I doubt they made that 100F.
Knowledge is power, but only if applied in a timely fashion.
Water sloshing about my sawzall makes me tingle like pizzing on an electric fence.
Never heard of double insulated tools and GFCIs?
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The information in this thread now has me wondering. I was going to cut up the fuel oil tank in my basement with a metal cutting blade on a concrete saw or use a sawzall. Thought I could save myself the $350 that a local company charges for removal. While I am skeptical about the combustibility of the fuel oil vapor, I also don't feel safe ignoring what I've read here.
Piffin,
I think you are incorrect on this one. (rare occurance) When I was a young man I worked in a maintenance department that was charged with the upkeep of 18 homes on the compound. All had fuel oil furnaces. One evening I was trying to get one to light, it fired then went out. I hit the reset and the atomized oil started going into the now warm fire box, I did a hot start and BOOM it blew me across the room, the doors to the old fire box open and the metal chimney pipe off the wall.
The vapors are explosive. I would fill it with water. I think you have just been lucky in the past. Glad for your good fortune. DanT
Yep , But the checks in the mail , we will get it done on time , Promise I'll pull out in time .
on a slightly different note..I am contemplating using an old propane tank..30'' dia. x 6' long for a wood stove body..it would have a door on each end with neo-ceram glass ( hot proof)
besides the obvious ( purge the old propane fumes) any good Ideas on the feasability..?
The plan is to get the ends off..add a shelf/baffle near the top with smoke channel openings to serpentine the draft to the flue collar..use the ends with the glass now installed and gasketed, reversed so the part that was the convex out side now faces inside..and hinged..add a gasket flange and a lock/handle mechanism..oh and a slider for incoming draft
it's either this route or pilfer some flat plate steel and make a sq. box..
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Repairs, Remodeling, Restorations.
Old Propane tanks are a bomb ready to go off? From what I have been told the propane actually soaks into the pores of the metal. The risks are not worth the presumed benefits.
Thanks for the heads up..while "from what I have heard" may be accurate, I would like some real factual evidence.
I have made a few barrelstoves from 55 gal. drums..at least one that had stored MEK in it's prior incarnation..is LP more readily absorbed by steel then MEK?
I would think the guy I have in mind for the cutting welding may have some input..lol..it's his butt going to the moon.
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Repairs, Remodeling, Restorations.
I have heard the same thing about old propane tanks. People want to use them as air compressor tanks and experienced hands say to avoid them.
I think the recommended method for cutting into a used fuel oil tank is with shears, air chisel, or maybe a sturdy nibbler. Even the air chisel can create a spark so caution is advised. I like the previous suggestion of dry ice. Not only could it cool the remaining crud, but the carbon dioxide would likely purge out much of the air and render the remain too oxygen deprived to support combustion. Don't know just how much you would need, however.
I lived near some refineries outside Martinez, CA, and more than one worker was launched into low earth orbit from working on crude oil tanks. They tended not to survive reentry...
"I like the previous suggestion of dry ice. . . . . Don't know just how much you would need, however. "
Each pound of dry ice will sublime to 65 gallon gaseous carbon dioxide. e.g. 4 pounds would fill a 250-gallon tank. If only the top of the tank is open, the CO2 (beign cold and heavy) will nicely fill from the bottom up and displace the O2.
Go have lunch while this happens. A few minutes is not enough time, typically, for the CO2 to sublime completely - the heat of vaporization keeps the remaining solid cold.
Helpful hint: Don't even think about plugging the tank with dry ice inside. 1) you want the O2 to flow and 2) we're trying to PREVENT an explosion. David Thomas Overlooking Cook Inlet in Kenai, Alaska
Ok ,If you plug the 250 gal. tank with dri ice . How much do you need ,and how long do you leave it cook to make a 300 gal tank ?
I think dry ice used inside a basement is a hazard itself in that it (co2) is heavier than air.
CO2 is 12 carbon plus 32 for oxygen = 44
molecular wt of air is 29
so co2 is heavier than air.
the basement needs to be well ventilated.
4 pounds of dry ice goes to 260 gallons of gas. So it adds about 15 psi to a 250-gallon tank. What are those tanks rated to? Tested to? 300-500 psi? So they are probably good for at least 1000 psi?
To make the 250-gallon tank go to 2000 psi, you'd need about 500 pounds of dry ice.
A much quicker way way to go to 2000 psi would be to add 0.2 pounds of gasoline or propane, stir well, install an ignitor, and get WAY far back. But we were trying to avoid that kind of thing, right?
When you fill a small glass vial with dry ice and (quickly) leave it on a fence post, it turns into very small pieces of glass about 3 minutes later. Probably goes to 1000 PSI before it shatters.David Thomas Overlooking Cook Inlet in Kenai, Alaska
David,
That is interesting that it only takes so little dryice to make so much pressure.
I don't think that a feul oil tank is rated for even 200# I don't think I would want to be near it at anything over 100psi . Those large flat sheets tend to puffup very easily.
Ithink propane tanks are rated for 200-300psi. They might hold a 1000 psi . I would want to be a long way away from that experiment also .
I found this on a website about converting propane tanks to air tanks.
"Normal propane cylinders, such as those used with portable grills have pressure relief valves set to 375 psi. PRV settings for ASME (American Society of Mechanical Engineers) tanks are 250 psi. DOT engine fuel cylinders use PRV settings of 312.5 psi."
Yes, fuel oil tanks are designed only for atmospheric pressure (and hopefully earthquake loads. There have above-ground tanks that failed when someone put chloronated solvents in them (density = 2.7) instead of fuel (density = 0.8).
Ever been next to a 55-gallon when it "pops" from vapor pressure inside going up (or down)? Not dangerous, but it gets your attention. DOT-h 55-gallon drums (that's 45 gallons, Canadian) get ugly around 6-8 psi and really ugly at 15 psi.David Thomas Overlooking Cook Inlet in Kenai, Alaska
many gas tanks and ships tanks are designed for minimal pressure - a pound or so.
Hadn't thought of that for the 4th David, good idea!
55 drum out in the yard, 50 ft air hose, plug the air hose to the compresor and wait till it blows!
Heard a lot of 55s pop . Reminds me of one of my brothers buddies wanting to do some welding on his tow truck . His gas tank filler was on the side he was to weld on . He wet a bunch of shop rags and wraped them around the filler cap . Then he started welding . In the meantime my brother had rounded up his 20# sledge . hit the other side of the tow body with enough force to clean the road dust and rust from the whole truck. Never saw a guy exit the shop at that pace before . I think he was heading for the terlet.
With friends like that . . .
I have seen that one before. I still bust out laughing every time I see it. Thanks.
I used the information in this now-old thread and finally cut up my basement fuel oil tank. Thanks! I used a sawzall. I left the bottom portion uncut, threw a half dozen rags in it so I could carry it up the stairs/outdoors without fuel oil spashing all over, and set fire to it. Every trace of oil and gunk disappeared into ash. Finally it's gone.
The propane does not permeate the steel of the tank, but the ethyl mercaptan (stink juice) does adhere to everything and takes a long time to degrade. Years later you can smell the "stink" in a piipe that has been used for gas.
Locally there is a scrap/recycle yard that cuts down propane tanks by purging/filling with water and then torching or drilling open the remaining very small unfilled area. It may or may not pop when cut open but the volume is so small it doesn't matter.
Most of the tanks have been setting for an extended period of time with the valves removed to allow for venting and are usually quite empty.
.............Iron Helix
Sphere,
I've cut a few Propane tanks in my past.
The procedure I've used is to pull all valves and plugs, then set the tank in the sun with the openings on the bottom for a year.
Cutting them with a torch will cause a lot of pops and slags, however. The first fire in them will drive out any slight residual gasses.
One procedure that sounds promising is to remove all valves, etc, put the openings on top, drop in a pound or so of dry ice, wait 10 mins, then cut with a saw on slow speed.
Once you have one end off, you probably won't get a BOOM!!!, maybe just a SWOOSH!!.
SamT
I'll probably be more carefull cutting up oil tanks in the future but would neer cut a propane tank. With any of these, it is the fumes or atomixed particles that explode, not the liquid,
Usually, when I am cutting one up, it is to get it out of a basement closed area where it is cool and fumes are far less likely. guess that's the source of my luck.
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Thanks..I ain't got a year..gotta have heat this winter..dry ice or maybe scrap the tank and buy plate..$$$$$..then again, I also used a waterheater tank in the past for a shop stove..just for this I need a larger Dia, than most WH's. Gotta heat 2400sqft log leaker..
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Repairs, Remodeling, Restorations.
dry ice releases CO2 which does not support combustion.
saw z all with water spray on the blade to cool and prevent sparks is a good idea also
thats what I was thinkin..'cept oil for the sawzall blade..cutting oil like for drilling.
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Repairs, Remodeling, Restorations.
1 pound of dry ice will EVENTUALLY sublime to 65 gallons of carbon dioxide gas (if at room temperature). That would, if well mixed in the 800 gallon vessel, be 8% CO2 which would reduce the possibility of an explosion. It would certainly narrow the explosive range of the fuel vapors.
HOWEVER, it takes more than a minute for a pound of dry ice to sublime. It goes quick in hot water but takes a while in air. Also, the heavy, cold CO2 vapor will stay low in the tank and not provide protection for the whole tank until something causes the low,heavy, cold CO2 to mix with the rest of the vapors in the tank.
The times I've seen dry ice used on large tanks, it took a long time to displace the regulated amount of oxygen. Typically the contactor would switch to compressed N2 for future tanks.
Pulling the plugs and letting it sit for a long time is an excellent approach. Alternately, you could hook a BLOWER* up and ventilate it. I would be comfortable cutting on it after 20 or so tank volumes had purged and would leave the blower going while cutting.
* A blower and not a shop vac because the shop vac pulls vapors through its motor for cooling. That could go boom. A shop vac with blower option would be okay.David Thomas Overlooking Cook Inlet in Kenai, Alaska
Dave,
Yeeeah, the blower!
I've never had to use dry ice, I've always had long hot summers to "dry" out the tank. Interesting about 1lb only equals 65cf.
I have used the bottled nitrogen, cuz that's what was available.
I've also seen them preburnt. Build a fast burning pile of brush around them, and watch from a distance. Got a 10' flame out the valve that went whoop, whoop, whoop, for a second and the show was over.
Sphere,
I figgered you would be using a blade and oil to cut with. But no'in how stuppit and iggerant you is, me gotta remine yu do it outside away from de home.
True story. Baad true story. . . 2 farmers were working on a truck in the field as it wouldn't start. They tried this and that and decided the in tank fuel pickup was clogged. Tried to use bottled O2 from the welding rig to pressurize the tank. Explosion killed both of them. Closed casket services. One was my accountants husband. Sad.
SamT
outside away from home? what fun is dat?
hell man, I gotta cut it to MOVE it..it is outside lol. bigger than I thought too..looks like a 500 gal. perfect for what I need just a challange to do and get in the house after an outdoor burnoff..
your farmer story reminds me of a guy I knew in Pa. had a bent frame on his P-up..chained it to a tree and floored it..went through the windshield...killed hissef.
I figgure a ten pack of 'fire/rescue' or 'torch' blades will do it..I got a buddy for the MIG work..my Lincoln is too small I think. An I am not a very good welder.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
"Interesting about 1lb only equals 65cf"
Nope, I posted that 1 pound equals 65 gallons. At 0.1170 pounds/cubic foot, CO2 is 8.5 cubic feet to the pound.David Thomas Overlooking Cook Inlet in Kenai, Alaska
Coolest thing I saw done with an old propane tank was making a mini-submarine that really worked. It is on display on a pier in San Francisco next to a WWII sub.
The two effective (but hard to achieve) features in a wood stove that would help a lot are 1) pre-heat the incoming air - for instance a heat exchanger off the flue pipe. And 2) downdraft through the coals. Easy with a high-temp blower, harder with natural convection. But bringing flue gases through an area of coals reduces the emissions and ups the efficiency by burning the smoke and vapors. A catalytic does the same thing, but has a narrower temp range for operation.David Thomas Overlooking Cook Inlet in Kenai, Alaska
did you mean preheat the supply air?..I'd have to have a fire first then huh? lol.
An yep I know about the catalyic effect..
This is a strange one I got going on in my head..it has to have a MAX. 6'' flue, the firebox can be any size provided that the draft openings don't exceed the flue capacity.
The larger FB is mostly for scale of where it's going, and I also don't enjoy cutting "stove wood" real short. With two glass ends I also want it long enough to not knock out a door when loading from the other side.
The blower idea for cutting is real interesting..so is the submarine, but the KY river is a little fast for me in a steel coffin.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
' but,they said it could'nt happen" (as he sails thru the air)
Actually, Diesel fuel don't ignite until its approx 140 F.
So use a 'cold ' cutting method .
"but,they said it could'nt happen" (as he sails thru the air)
How many people's last words were, "Watch this!"?David Thomas Overlooking Cook Inlet in Kenai, Alaska
Piffin: I'm not a chemist, but I studied chemical engineering and my last 16 years of environmental engineering has mostly been with spills from underground fuel tanks.
An empty gasoline tank is more likely to go "boom" than a full one. In a full one, the vapors are too rich to burn - they are above the Upper Explosive Limit (about 5% by volume) - typically they are 50-70% depending on temperature.
Diesel (which is used as fuel oil in some areas) is less volatile, but if the vapors are above 1% (the Lower Explosive Limit), they can explode. And kill you. And all the other people on TWA Flight 800, for example. This is more likely to occur with fresher fuel, on a hotter day with tank in the sun and especially if any solvents were used to clean the tank.
To greatly reduce the chances of going boom, several detergent rinses would help. Laundry detergent is great (and cheap) and the hot the water the better. A steam cleaner or a pressure washer hooked up to the hot tap is much better than cold. And you don't need to flood the tank, multiple low volume rinses are much better than a single big rinse and generates less waste water. Working on a cold day in the shade would be prefered.
Flooding with detergent/water would be very safe.
Note that in many areas the recycling of used fuel tanks is regulated and you need to be registered and certified to do so. Partly to minimize explosions but also so dirty tanks and dirty rinse water are properly handled.David Thomas Overlooking Cook Inlet in Kenai, Alaska
Fill it with water, buy a few good blades and use a Sawzall. Depending on how much heel is left and where you live, you may have to make arrangements to dispose of the contaminated water.
Either of the above tools plus eye and ear protection.
Fumes no problem with fuel oil - just gas. But make provision for catching the sludge.
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I'm certainly no chemist ...
but I do know a good way to scare the snot outta half the guys in the garage ...
when the occasion of a bucket fulla gasoline presents itself ....
do a "watch this" to get their attention and throw a lit match into it ...
half the guys will scream like little girls and jump ...
the other half already know .... gas vapors explode ... gas(liquid) don't ...
and those vapors only explode when inside a container of some sort ...
and a bucket fulla gas don't qualify.
all ya have is a fun way to put out a match.
Good clean ... potentially dangerous and explosive .... fun ......
ok .. here's another ... similar idea ... not really .. but I'll include it too ...
many years ago ... my brother and law/fishing partner showed me a "trick" ...
Ever see a match burn twice? he asked ...
he lit it ... said that's once ... then stuck it to my forearm ...
that's twice!
grown man burning a kid .. something wrong wit that guy ....
or me ... after yelping in pain ... I thot it funny enough to remember and try on my buddies ...
ahh ... fun with matches ....
Jeff
Buck Construction, llc Pittsburgh,PA
Artistry in Carpentry
Huh, so that's why it didn't work. I remember as a kid thinking I was going to detonate a glass container of gasoline.
Had it sitting on a sidewalk on an inverted foam cup with a firecracker under the foam cup with a long fuse.
I was disappointed.
Not to give anybody ideas, but it is near the 4th and related to the way this topic is going.
For a non-pyro 'boom', take the valve off a 5 gal propane tank and put about 3-4 pounds of dry ice into it, (or 30# into old water heater) then a pipe plug with the overpressure vent also plugged - get about 300 feet away and leave it in the sun - nice boom in a little while. Heelps to grind a notch halfway around the tank first, cause there are a few of the propane tanks will withstand the 1071 psi, then you gotta shoot it 'cause you don't want to walk anywhere near.... .
Next topic will be stochio oxy acet. mix blown into a tire to 5 psi then shot - again get far away.
BTW, IMHO, flt 800 was a KKV, not diesel fume self ignition.
my neighbor seats tire beads by squirting in starting fluid, and then a lighter near the unset bead..POOOMMFFF..tire is filled. Slick as snot way to set a bead on a lawn tractor tire.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Can you trade your lp tank for NH3 tank ? If not use the blower setup and take out all the plugs when cuting . or for fun the fire method.
That one scares me. Here's why -
When I was a young feller, our neighbor had a recapping business so he mounted a lot of tires. He was filling with air to seat the bead one day and when it went POP, the rim broke into scrapnel and he lost half his hand and a piece of his face.
A rare one, I know, but it sticks with me still. You'd have to see him to have the same reaction, I guess.
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Don't try that gas in a can trick when it's warm. The vapor will rise over the edge of the bucket and spread along the floor. Then when Mr. Smartypants throws in the match he may find the WHOOOMP goes up his pant's leg. Sounds like the Homer Simpson BBQ method.
"The vapor will rise over the edge of the bucket and spread along the floor. "
Don't you love it when it burns off your leg hairs, inside your pants? A lot quicker than shaving them.David Thomas Overlooking Cook Inlet in Kenai, Alaska
never been done in doors ... unless you count a garage with on open door indoors ...
but as far as I can remember ... I don't think I've ever done it when it's anything we'd call cold outside .... so I'm sure it's been done while hot outside.
maybe in the back of the garage .. in hot weather ... you'd have problems ...
but any kinda breeze is gonna blow any fumes well away ...
gas just ain't that flamable.
Neither is grain alchol .... tried to test some on a fraternity house floor once ... we didn't think it worked ... after we realized we'd just tried to light a hardwood floor on fire ... we figured we were more drunk than not?
as a bartender .. I can attest ... to the fact that 151 needs to be warmed first before it'll take flame ..... either it's lots colder here in Pgh than we realize ... or all those flaming shots in the movies are faked!
JeffBuck Construction, llc Pittsburgh,PA
Artistry in Carpentry
Something tells me that you could start a thread entitled,"Embarrassing ways to gain admittance to the ER" that could rival the stories on the Darwin awards site.
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Yeah, I could. Let me give you a clue on foreign objects in body cavities. Own up to the real orgin promptly. We're not going to believe any made up story. You'll get a lot less raised eyebrow snickering when you tell the truth.
While I'm on this subject, remember that once you pass the equator on a round object it promptly pops past the sphincter and disappears. If it gets late at night and I've had a beer I could tell you some anonymous stories involving disappearing whiffle balls and the use of cordless drills to retrieve them.
I've been following this thread and have read the posts, including those from people who've cut up fuel oil tanks with neither problems nor any thoughts that they could have had problems. However, some of the warnings have made me quite paranoid about cutting up that 280 gallon tank in my basement. Would you cut it up? Sawzall? Metal cutting abrasive disc on circular saw? My back is too sore right now to use a concrete saw.
Must be my age that makes me forgetfull.
I think I answered or at leaast meant too that I wouled not hesitate to use a sawsall with four or five metal cutting blades, ( not all at once) and eye and ear protection.
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Thanks. Sounds doable, as it has been done by many before.
I once saw a guy run a hose from the exhaust pipe of a running car into a gas tank from a car in order to eliminate the oxygen in the tank.
He went and welded a patch on that tank with that configuration.
'Course I was a good ways off in back of him at the time.
Guy always was kinda strange.
OK, Storytime.
I was on a condo job and a guy was trying to get a trash pile burning by pouring some liquid out of a can onto the fire. Apparantly, he thought it was kero or fuel oil, but he had the can of mixed gasoline with a pour snout on it.
Of course, the fire on the pile got big in a hurry, which made him sort of flinch and jump back, but he was still hilding the five gallon can which had a small flame at the tip like on a malotov cocktail. It was only burning enough as it got oxy right there.
But everyone started yelling things like "Run", jump", "Throw it away from you", So he threw the can away and ran the other direction. as the can rolled across the concrete, every roll produced a spray of flaming gas for abourt five or six roll opvers intil it came to rest with the snout buried in some debris where it promptly went out. But the sprays of burning gas were interesting fro a few minutes 'tilll the fuel got burnt off.
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Frank,
I don't think you should be cuting up the tank myself . . . But, sometimes ya gotta do what ya gotta do.
So, first pour 2 gals of naptha or mineral spirits in the sun warmed tank. Slosh it around every couple hours, then drain into a container so you can take it down to the petroleum recycler. Repeat this till the spirits come out thin and not %100 black.
Now dump a large bottle of Dawn Dish Soap, a small box of Tide, and a pound of driveway cleaner into 10 gals of hot water. Bring the water to a boil if you can, then dump all that into your tank and roll the tank around for 15 minutes. Repeat if the tank is not clean. You can reuse the water as long as you get it to make a bubble.
Dump the mixture out and while the tank is still wet, make your cut. Once you have a largish opening in the tank, it will no longer explode. Might swoosh or burn, but won't be a bomb. Set the soapy mix aside to evaporate, then properly dispose of the petrochemical residue.
When I worked in the oil field support industry, the Tide, Dawn, and driveway cleaner was the most effective water based formula we found for cleaning crudes and tars off the equipment. An overnight soak in an unheated dip tank would remove 2" of crude the consistancy of Vaseline.
Samt
Skip the naptha! Using lighter hydrocarbon increaces the explosive risk. Just go straight to your detergent cocktail. As you say, it is very effective on pretty heavy stuff and fuel oil / diesel is easier to clean than those.
Hot water & detergent - Yes. Solvents - No.David Thomas Overlooking Cook Inlet in Kenai, Alaska
I'm a relatively cautious type, but I think you guys are scaring Frank needlessly.
I have cut up a few of these.
Fuel oil vapors can only explode given enough temperature and pressure. The tank on TWA 800 (I saw the wreckage in person, long story) was not open to the atmosphere, and sat directly over very hot A/C units.
Basement temperatures are not high. Any pressure (there will not be much), and indeed most of the vapors can be release by opening the tank to the environment. Remove fill/vent pipes, and plugs before cutting.
I use a combination of sawsall and an angle grinder with a cutting wheel.
Have a plan for containing the sludge, as there is likely to be a couple of inches of primordial ooze. Organisms actually grow at the oil/water boundary near the bottom. You can literally shovel the gel out. Several 5 gallon pails with covers is probably the best choice.
I made 2 workbench tabletops out of my old tank.
Best of luck.
Frank, I can't answer any questions about cutting the tank, but I just want to add that once the tank is removed don't forget to remove the pipe from outside that was used to fill it. You don't want the oil delivery guy to get the wrong house and pump 275 gallons of oil into you basement.....
I watched a crew cut up and haul off a large heating oil tank. The way they did it was to drain it down into 5 gallon buckets. The inside was swabbed with rags. A detergent solution was sprayed in and blown out with compressed air. Everything was saved for proper disposal.
Once completed dry ice was added. This releases CO2 gas and lowers the temperature of any small amount of remaining oil below its flash point. In a couple of minutes the CO2 was gassing out of the top and they used a Sawsall to cut the tank in half.
They told me that sometimes they filled the tank with water, used a CO2 cylinder and might have used a cutting torch but the saw was safer. They said the trick was to keep the area flooded with CO2 as this kept the oxygen at bay eliminating the chance of flash over or explosion.
Frank,
This is one of the things the company I work for does a lot of, so I feel qualified to advise you.
The first thing I will suggest is that you contact a professional company that regularly does such work. It's possible that your state has a program that pays most of the cost of proper removal and disposal. If so, a local company may do what ours does, and pick up the deductible cost in exchange for getting the work. Net cost to the customer is $0, plus no worries about fire, explosion, or violating environmental regs.
If that is not an option, you may be able to do it yourself, but I don't recommend it. I can tell you for sure that heating oil CAN explode from sparks during the cutting process. I own a house built by a man that saved a few bucks by cutting up a tank himself. Took him three days to die after the explosion. Taking even a small risk of this to save a few hundred bucks seems like a bad bet to me.
The most common methods of preventing explosions involve either displacing the air with co2, usually from dry ice, or purging with LOTS of fresh air. We monitor the vapor level inside the tank with a special meter that you probably can't easily rent. Without adequate vapor monitoring, you're playing Russian roulette. The human nose has been thoroughly proven NOT to be an adequate vapor monitor.
While flooding the tank with water should prevent fire or explosion, if there's any significant amount of oil in the tank, you then need to figure out how to keep it from spilling on the ground. If you can manage that, you may be OK.
On the other hand, depending on your locality, it's quite possible that fines for getting caught doing it wrong might amount to thousands of dollars.
Good luck
Dave
Thanks Dave (and everyone else who took the time to respond.
I think I will try to see how much it is to dispose of this without cutting it myself. I would prefer not to have an explosion on my property - or an oil slick either.
Frank
Auto mechanics have some sort of "wash" they use for gas tanks before they try to solder/weld on them. I would assume that a well-stocked auto parts place would have this.
The other alternative would be to dump a bunch of dry ice (5-10 pounds, I'd guess) into the tank. The CO2 would displace any oxygen in the tank and also keep temps down. In a pinch you could use vinegar and baking soda.