Canned air is extremely explosive...

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olympic

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Just a note on burns here. If you have a stove-top tea kettle, make sure the lid is on properly before you pour that boiling water into the teapot. Though not quite "live," the steam will poach your little fingers in a trice--and please don't ask me how I know....
 

Ken I

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I had a similar experience with a hand held air horn - the "air" is in fact butane.

It ignited producing a big ugly yellow billow of flame - no harm done but nonetheless a surprise.

Regards, Ken
 

RonGinger

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I always was fascinated by naptha engines used in boats. They used the naptha not only to make the heat, but as the working fluid in the boiler. This was done to get around laws that required licenses to operate a boiler. Boilers were defined as steam and water items, so naptha was not against the law.

I have seen one naptha launch, at Mystic Seaport Museum. Would make an interesting model.
 

Master

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About 1960 in our town an old galvanized metal water heater safety valve stuck. It went through the roof and traveled a good distance before it landed. Luckily no one was hurt.
 

Steamchick

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Hmmmm... A few salutary tales there. Hope you fingers heal quickly. We all know the intense pain from even tiny burns....
I once saw a motor repair man spray WD40 into a wet engine bay of a car with a very hot engine, the was running badly with sparks all over.... The loud "whoomph" as the whole engine bay was engulfed in a large plume of flame was drowned out by his shouts of "Oh F........!" The nearby family - only 2 yards away - looked at him and were upset by the swearing while he grabbed a fire extinguisher and extinguished their burning car.... Needless to say, the car was taken away on a trailer.....
Working in car manufacturing, we were taught that most car fires in accidents are started when Brake fluid hits hot exhaust manifolds.... it has a very low flash point! Petrol and diesel fuel don't flash so easily, but always take care with any fluid and hot surfaces.
Old fire extinguishers use flame extinguishing chemicals that were converted by hot metal into toxic gases, e.g. phosgene, like those used in trench warfare in the Great War.
And weedkiller sprays contain chemicals that can be absorbed through the skin and kill nerves.....
Take care,
K2
 

TSutrina

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Such a list of people getting hurt by explosions. Lucky I do not have a story. As a young boy we had fun creating a dust explosion. Candle sitting on the ground at the center of a 3 inch diameter by about 6 foot long aluminum pipe resting on bricks to have an air inlet. We dropped down a little bit of particle board saw dust. About a third of the times a flame shot out the top of the pipe. Not a little flame but at least a foot above the end of the pipe.
As an adult engineer I designed phase change products a few times. The water tank going through the roof is different then other examples. A water heater doesn't have an air bubble when it is at normal hot water temperatures. As it gets hotter some air may come out of the water as bubble comes out of pop. Still there is not sufficient are to produce the launch of the water heater. What happens is that the water is super heated so that the actual vapor pressure of the water is well above the city water pressure. Something causes a trip of the water to go out of super heat. The energy in the water is converted to create water vapor. This creates a huge water bubble at the water pressure. The flame that heated the water caused the metal to be the weakest so if fails. Water is pushed out at a high velocity with the reaction force lifting the heater up. As the pressure drops due to water being pushed out more water boils so water is push out until atmospheric or a lower pressure is reached.
 

doc1955

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Mr. Rupnow and ShopShoe,

I havent seen gas irons before but it does make me think of those old gasoline powered torches. Same configuration with the pressure pump and they would compete easily with Oxy-Acetylene torches. Very unsafe though! You can still find them for sale on Ebay every now and again.

Thanks,
-J.Andrew
Lol among other things I collect old irons I have many that you sat on a potbelly stove a couple coal fired and a couple gas. I attached some pictures of the gas.


Speaking of canned air canned fix a flat is bad news also. once put in the tire it becomes a bomb and you can set it off with a spark while removing tire from rim not good.
 

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GrahamJTaylor49

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I did my apprenticeship as an Aircraft Toolmaker and ended up as a self employed compressed air engineer. I am also a pressure vessel examiner and carry out work for the HSE and some insurance companies. Whilst on a course with BCAS in London an example of how dangerous compressed gasses can be. This includes compressed air. A large car franchise in London had a workshop that had a compressor. The fitters in the workshop complained to the manager that the compressor was leaking and could he do something about it. The manager investigated the noise and found that the safety valve was lifting and to paraphrase the saying "A little knowledge is a dangerous thing" replaced the safety valve with a plug. A little while later the motor burnt out and instead of getting it rewound or replaced with the same size motor, he found a spare motor in the stores. Unfortunately, the replacement motor was of a size nearly double the size of the one that had failed. Now on compressors the motor is sized to the pump so that in the event of pressure switch failure the motor will stall before there is an accident. Now with the safety valve removed and replaced with a plug, the motor now being way larger than was required the "apprentice" who was supposed to turn everything off when leaving for home in the evening forgot to switch off the compressor. During the night the pressure switch failed ON. The next day when the manager and staff came into work they found that the works was missing two walls and the roof and that four customers cars were rite offs. At the public enquiry the comedy of errors that had led to the devastating explosion was laid at the feet of the manager who, due to his interfering with the plant, had caused the problem. The insurance company used this as an out and refused to pay out and the manager was fired. Had anyone been inside the building at the time they would have been killed.
Compressed air, which is a gas, is more dangerous that electricity, and as we all breath it and consider it as harmless it cannot hurt us. Oh yes it can. So gentlemen and ladies, please be careful and remember compressed gasses are dangerous.
Please keep making these models and I will put the story of my Stuart Turner Major beam engine, which I will finish one day,
Regards to all,
Graham Taylor. B.Eng. Verwood, U.K.
 

harborfreight8x12

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Lol among other things I collect old irons I have many that you sat on a potbelly stove a couple coal fired and a couple gas. I attached some pictures of the gas.


Speaking of canned air canned fix a flat is bad news also. once put in the tire it becomes a bomb and you can set it off with a spark while removing tire from rim not good.
You mention tires becoming a "bomb", in my youth I worked in a scrap yard and we used to air up tires with a propane bottle. When it was time for a load of scrap iron we would pile all the junk wheels and set them on fire and wait for the ones filled with propane to .......................................!
 

TSutrina

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I did my apprenticeship as an Aircraft Toolmaker and ended up as a self employed compressed air engineer. I am also a pressure vessel examiner and carry out work for the HSE and some insurance companies. Whilst on a course with BCAS in London an example of how dangerous compressed gasses can be. This includes compressed air. A large car franchise in London had a workshop that had a compressor. The fitters in the workshop complained to the manager that the compressor was leaking and could he do something about it. The manager investigated the noise and found that the safety valve was lifting and to paraphrase the saying "A little knowledge is a dangerous thing" replaced the safety valve with a plug. A little while later the motor burnt out and instead of getting it rewound or replaced with the same size motor, he found a spare motor in the stores. Unfortunately, the replacement motor was of a size nearly double the size of the one that had failed. Now on compressors the motor is sized to the pump so that in the event of pressure switch failure the motor will stall before there is an accident. Now with the safety valve removed and replaced with a plug, the motor now being way larger than was required the "apprentice" who was supposed to turn everything off when leaving for home in the evening forgot to switch off the compressor. During the night the pressure switch failed ON. The next day when the manager and staff came into work they found that the works was missing two walls and the roof and that four customers cars were rite offs. At the public enquiry the comedy of errors that had led to the devastating explosion was laid at the feet of the manager who, due to his interfering with the plant, had caused the problem. The insurance company used this as an out and refused to pay out and the manager was fired. Had anyone been inside the building at the time they would have been killed.
Compressed air, which is a gas, is more dangerous that electricity, and as we all breath it and consider it as harmless it cannot hurt us. Oh yes it can. So gentlemen and ladies, please be careful and remember compressed gasses are dangerous.
Please keep making these models and I will put the story of my Stuart Turner Major beam engine, which I will finish one day,
Regards to all,
Graham Taylor. B.Eng. Verwood, U.K.
The only good thing to say is at least there wasn't combustible vapor or gas in the air, like the oil lubricant and a spark created when the failure happened.
 

Bentwings

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Worked in a big truck shop building a race car for the owner. They regularly used carb cleaner, brake cleaner and ether starting spray to mount semi tires. Spray it and light it, boom tire seated. It’s amazing they didn’t blow themselves up. I stayed in the car shop while they mounted tires. It’s no wonder why big truck tires explode if there is residual flammables in them. Steel portable air tanks can accumulate water in them then they get rust internally weakening them. Most of the time it just start arts as a leak but but they can explode too. An R&D lab I worked in did vessel pressure testing but it was always hydraulic. In a water tank. They just split and leaked water all over. Once in a while a weld failed but in the water tank it just created a big wave gas pressurization was not allowed.
 

Steamchick

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In the frozen northern countries, Iceland, Finland, etc. They do a lot of winter off road stuff and low pressure sin tyres to improve grip on snow and ice... but tyres pop-off frequently... After re-fitting, they squirt liquid butane into the tyre - it is sub-zero - then ignite it with a whoomph to inflate the tyre and set it on the rim... no idea how long tyres last though....
K2
 

Bentwings

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In the frozen northern countries, Iceland, Finland, etc. They do a lot of winter off road stuff and low pressure sin tyres to improve grip on snow and ice... but tyres pop-off frequently... After re-fitting, they squirt liquid butane into the tyre - it is sub-zero - then ignite it with a whoomph to inflate the tyre and set it on the rim... no idea how long tyres last though....
K2
I’ve seen this done on big truck tires too. It’s a scary process.
 

MRA

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Working in car manufacturing, we were taught that most car fires in accidents are started when Brake fluid hits hot exhaust manifolds.... it has a very low flash point!
I found that out when annealing a bit of brake pipe on a car, where I had sheared-off the nipple (and the flare on the end of the copper pipe) when taking off a very knackered slave cylinder. So when my ebay flaring kit turned up, I thought it would help to anneal the remaining pipe, on the car and full of (well, fairly full of) fluid. It didn't half make me jump, and I probably had my head inside the wheel arch when it went pop!
 

Eoin

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This has been a most interesting series of posts, to say the least.
I haven’t had any explosions but have been using various insect and ‘smell nice’ sprays for years to start reluctant engines, particularly the now ten year old lawn mower, it’s been a reluctant starter for all of its life but a quick spray from a can (above) sees it spring into life.
Once its hot it starts normally so I’ve never used the sprays around a hot motor.
 
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