Be aware Fatal Error!

[stuvy]

That would depend on the "fuel" if the flame front (I think it's called that) moves very fast, ie creates lots of gas very fast then even if the bungs were out, then it could explode, as the bung hole is not big enough for the gases to exit fast enough.

rather than the barrel exploding wouldnt it just fire like a missile?

 

[stuvy]

I have chopped open a few engine oil barrels to make scrap metal bins.
Opened them using an angle grinder, never even seen a wisp of smoke.
Am I putting myself at risk or had this poor guy's barrel had something a bit more volatile in it. Petrol?
Something to think about before i do the next one.
Maybe open it with a jigsaw.

iv cut a few open too and never done this in the past, im going to think about it in the future though. As in a rinse with water a leave for a day

 

[ChrisJohnsSculpture]

One of the big problems is that flammable material can leech into seams and even the steel itself especially if there is any corrosion inside, this can then be forced out when it's heated, it takes very little vapour to cause an explosion and it's very hard to clean out every last bit. Even things like engine oil which aren't particularly flammable in themselves can liberate explosive vapour, especially when heated.

The safest thing is to fill with water as this physically fills the space, displacing any vapour.

It's one of those things where most of the time nothing will happen but you only have to be unlucky once....

 

[hotrodder]

rather than the barrel exploding wouldnt it just fire like a missile?

The explosion is multidirectional so barrels/petrol tanks etc tend to do this sort of thing* usually except that due to there typically being a smaller opening/escape route for the gases it can be a LOT more violent... they tend to jump more, often change shape from the force or even split open.

As said everything also depends on the flavour of the fuel and the mixture... petrol normally burns in an engine but can explode (pinking/detonation). As Shox said it all depends on flame speed... low explosives like gun powder usually just burn VERY fast (deflagration is the precise techy term). 'High explosives' detonate rather than burn, something to do with exothermic reactions and supersonic shockwaves

* i still start giggling way before the 'Wooomph!' despite having seen it many times

 

[Rrunnach]

I use to deliver a unit to fab/weld students titled "Repairs to Tanks, Drums, and Vessels".

Lots of examples from various industries, most horrific was at an MOD naval repair yard, guy cut in half making repair to MTB fuel tanks, which went off, not all procedures were followed, BTW, this was many, many years ago.

At our old campus, one arty-farty not got a clue evening class student, walks in with a 15kg butane bottle, his plan was to make some kind of garden sculpture, he changed his tune when I ran a few scernario's by him.

I've also had folks ask me to repair fuel tank for bike or high end rare breed car. I instruct owner to have vessel steam cleaned, I also ask for a certificate stating cleaning procedure and safe to hot work. Because if it did go BOOM, at least my family can sue someone!!!

Sounds a bit OTT, just reflect back to OP, a man is dead.

 

[Drains]

Yep, steam cleaning is the standard way of moving such containers on to other uses safely.
An "oil drum" means a 44 gallon drum. There's nothing to say what's been in it. I see them having held allsorts of things, not least high volatile solvents etc, as well as extremely unpleasant chemicals (although the plastic drums tend to hold the worst liquids).

 

[chunkolini]

I remember seeing an idiot trying to light a fire in an old oil drum, chucked in the logs and kindling then a pint of petrol.
Spent about 5 minutes looking for a light, dropped in the burning rag. kapow!!!!!!
Amazing; especially the bit when his wife punched him.

A mix of hydrocarbons and air/oxygen burns very very fast, real fast.
I think the US military calls it a Thermobaric bomb.
Get a (stoichiometric?) mix of fuel gas and oxygen and light it up. Not a good idea.
I read somewhere weight for weight petrol has more explosive force than TNT. if you can get the mix right in air. They might also have been called Cookie Cookers because of the pattern left underneath the detonation point.
is the difference something like power and torque? a gas explosion has massive destructive force in a very condensed time makes a massive bang, but wont damage a solid structure unless it is enclosed. Whereas TNT etc will blow a crater into the floor but make a smaller bang.
How do I know this stuff? not sure of the science but I do recall a session with my old chemistry tutor on this one.

I bet this is one of those situations where you have to do everything exactly right/wrong. So unlikely it should never happen, but if it does.......

No more chopping oil drums up with angle grinders for me.

Thank you Gordon and Al.
Chunkolini.

 

[Lewis Medlock]

The safest thing is to fill with water as this physically fills the space, displacing any vapour.

I do that and gas the top off.

Jim

 

[CRB]

I remember reading once that if you were quick enough, petrol would extinguish a match. It was just getting through the fumes that was the tricky bit.

 

[tttonyyy]

The Daily Mail said it contained gasoline and the poor guy whacked his head going over backwards on the patio.

Periodically I give away barrels, people take them for garden burners and barbecue projects. As they were used for Methanol storage I rinse them three times with water (Methanol is soluble in water unlike petrol) and stand them open for at least a week first. And the new owners get warned about the previous contents (though the labels on the top make it pretty obvious).

 

[stuvy]

The explosion is multidirectional so barrels/petrol tanks etc tend to do this sort of thing* usually except that due to there typically being a smaller opening/escape route for the gases it can be a LOT more violent... they tend to jump more, often change shape from the force or even split open.

As said everything also depends on the flavour of the fuel and the mixture... petrol normally burns in an engine but can explode (pinking/detonation). As Shox said it all depends on flame speed... low explosives like gun powder usually just burn VERY fast (deflagration is the precise techy term). 'High explosives' detonate rather than burn, something to do with exothermic reactions and supersonic shockwaves

* i still start giggling way before the 'Wooomph!' despite having seen it many times

A guy i worked with did this and was standing right over it when it went, even though i was midly concerned i did laugh til i was nearly sick and he over reacted shrieking "im blind, im blind"

 

[tttonyyy]

This is how to do it properly

http://www.youtube.com/watch?v=ANoKOmGOong

 

[chunkolini]

Interesting point from tttonyyy
The barrel was full of petroleum.
After the hysterical petrol hordeing (how do you spell that? 3rd attempt) a few months back are we going to be exposed to loads of idiots blowing themselves up?

 

[MattF]

After the hysterical petrol hordeing (how do you spell that? 3rd attempt)

Hoarding.

a few months back are we going to be exposed to loads of idiots blowing themselves up?

If that's the case, there'll be a few less idiots about.

 

[CRB]

If that's the case, there'll be a few less idiots about.

Darwin probably said something like 'Stupid people are a self-eradicating species'......maybe.

I remember reading this in Bike a very long time ago, and it was said to be the police interpretation of the evidence. ?True story?


Once upon a time, in some out-of-the way part of the country (take your pick of locations) a maniac took a rocket of some sort, and mounted it on the back of a car (make and model depend on automotive trends when the story is told). The maniac then sped down a deserted stretch of highway, and when he reached an appropriate spot, he lit the rocket. Unfortunately, the rocket (which was either a JATO bottle, a surplus ICBM engine, or an experimental Shuttle booster) proved to be far more powerful than the maniac anticipated. The car reached an incredible speed in a matter of seconds (somewhere between 150 miles per hour and Warp 9) at which point the car's brakes and steering became... ineffective. This development would've been bad enough on a straightaway, but through some error in planning or navigation, the maniac found himself hurtling down a road that curved sharply, not far from where he ignited the rocket. When the car arrived at the curve, it went straight ahead instead of negotiating the turn. Pilot and car then flew like an arrow (for a distance only limited by the imagination of the person telling the story), before crashing into an inconveniently-placed mountainside.

 

[tttonyyy]

Nah sorry that classic tale is false

http://www.snopes.com/autos/dream/jato.asp

 

[CRB]

That's the one

Never mind, Wylie Coyote lives on somewhere though.

 

[RonA]

I wonder if he did think about the risks involved beforehand or just attacked it, Would be nice to know what the drum had contained, but anything like that I am going to cut into gets washed,drained and air purged immediately before cutting and never had the slightest problem,

When I was still working often got asked to carry out checks on diesel tanks for rail diesel shunting engines before they welded up cracks. In times of yor we would have them drained, washed out & then part filled with water to the level of the crack before welding commenced. Laterly the tank would be drained, washed & the trickle purged with Nitrogen, which was much safer (albeit making sure the welder didn't get a mouthful of Nitrogen).

Feel very sorry for these people who work in small numbers like farmers, I would doubt they are privy to the red stripe safety alerts we were always getting raising awareness of issues like these.

 

[Shox Dr]

Well since this has turned into a story tellin thread.

When I first left school, I worked for a Construction Company on the North Selby Mine Complex. One day I was given the job of sorting the good concrete shutters from the bad, burning the bad ones, . It was a dumping ground for everything, at the back of the pit including hundreds of empty 25ltr barrels of Aqueous Hydraulic Oil.

We soon found that throwing them on the fire, would launch them skywards at a great rate of knots, although we then found that most would just blow the bottoms off... flying off in any direction (usually ours) like a frisbee on fet

 

[jimzzr]

I use to deliver a unit to fab/weld students titled "Repairs to Tanks, Drums, and Vessels".

Lots of examples from various industries, most horrific was at an MOD naval repair yard, guy cut in half making repair to MTB fuel tanks, which went off, not all procedures were followed, BTW, this was many, many years ago.

At our old campus, one arty-farty not got a clue evening class student, walks in with a 15kg butane bottle, his plan was to make some kind of garden sculpture, he changed his tune when I ran a few scernario's by him.

I've also had folks ask me to repair fuel tank for bike or high end rare breed car. I instruct owner to have vessel steam cleaned, I also ask for a certificate stating cleaning procedure and safe to hot work. Because if it did go BOOM, at least my family can sue someone!!!

Sounds a bit OTT, just reflect back to OP, a man is dead.

To be fair cutting open a empty propane cylinder is for several reasons actually safer than an oil drum. Firstly the contents have a high vapour pressure at room temp and thus once the cylinder valve removed is relatively easy to free of gas with eg. an purge. Secondly even if it did ignite the worst case pressure generated would be 8 times the initial pressure 1 bara if the cylinder is empty giving 8 bara overpressure which happens to be around the same as the vapour pressure of liquid propane. In other words an explosion wouldn't exceed the normal working pressure of the cylinder and unlikely to catastrophically fail in such a way as to seriously injure (unlike an oil drum or petrol tank).