ThomasPowers Posted August 27, 2012 Share Posted August 27, 2012 Perrin it's that sort of thinking that can get you killed! I have generated sparks using a hack saw on rusty metal before. Safer to be using a "dangerous method" with precautions than to use a "safe method" without them! Best of all is to use a safe method with precautions! Quote Link to comment Share on other sites More sharing options...
Dr Dean Posted September 4, 2012 Share Posted September 4, 2012 This isn't probably the safest method but it worked for me. I had a 20Lb tank that needed cut in half and I was a bit nervous to be close when it was initaly opened. The valve wouldn't budge even with a 36" pipe wrench on it. Here is the part where you have to remember I live out in the country. I set the bottle out at the 400 yard mark on my shooting range. 4 shots later with my 22-250 I had a well ventilated container, the bottle was empty before shooting. After retrieving the bottle it was filled with water and cut with a torch. Quote Link to comment Share on other sites More sharing options...
Bentiron1946 Posted September 4, 2012 Share Posted September 4, 2012 I like the sound of ventilating with a .22-250. Only problem with that is once I started ventilating I might forget to stop :D Quote Link to comment Share on other sites More sharing options...
Dr Dean Posted September 6, 2012 Share Posted September 6, 2012 Yes it was pretty cool! 1/4" hole in about 1/2" hole out. I would be willing to do some custom ventilation if the bottle was brought to my range. We may even have to take out some little orange ufo's. Quote Link to comment Share on other sites More sharing options...
Robert Yates Posted September 7, 2012 Share Posted September 7, 2012 It has been done many times be safe . Sam Seen 4 just 2 days ago turned into forges . Quote Link to comment Share on other sites More sharing options...
macbruce Posted September 7, 2012 Share Posted September 7, 2012 I like the sound of ventilating with a .22-250. Only problem with that is once I started ventilating I might forget to stop :D A man after my own heart...........Be aware, a bullet passing through a tank will NOT make it explode if there is fuel in it......It will explode after the remaining gas has had an opportunity to mix with air..... http://www.google.com/url?sa=t&rct=j&q=mythbusters+james+bond+propane+tank&source=web&cd=2&cad=rja&ved=0CCMQtwIwAQ&url=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3Drhti2xAB-Gk&ei=aYNKUP2uFtOHqwHsyYGACA&usg=AFQjCNGHpGrbC3mvJ7lE0OB4RySas5jQ8w Quote Link to comment Share on other sites More sharing options...
Bigcity Posted September 8, 2012 Share Posted September 8, 2012 i might have to vent one with my .223 :) but then again i would pry use the water method and cut it open while its full of water. i also agree with glenn about having a pro do it for me better safe than sorry Quote Link to comment Share on other sites More sharing options...
Zengineer Posted March 7, 2013 Share Posted March 7, 2013 I think I found the best possible way to do this. I bought a virgin propane tank, never been filled, brand new off the shelf for $34. Those of you in the US could likely find a substantially better price than that. Peace of mind, and keeping my mind in one piece is worth $34 to me. Quote Link to comment Share on other sites More sharing options...
Charles R. Stevens Posted March 7, 2013 Share Posted March 7, 2013 What was the new tank presher tested with? They have to be certified. I'd still take aproptiate precautions. Like having some one that knows the # to 911(fire fighter joke). Quote Link to comment Share on other sites More sharing options...
David Gaddis Posted March 7, 2013 Share Posted March 7, 2013 100 % dry air There are special regulations in the LP industry to vent the air....then a small charge of LP added...then venting that gas! This info came from my LP fuel friend. In a way it makes sense....no fuel / air mixture available to explode inside the cylinder, should the inevetible occur. The only way a cylinder can explode is to have more pressure inside than capable of holding, such as an explosion. carry on Quote Link to comment Share on other sites More sharing options...
Dale M. Posted March 8, 2013 Share Posted March 8, 2013 OK.... Propane Limits of Flammability - The lower and upper limits of flammability are the percentages of propane that must be present in an propane/air mixture. This means that between 2.15 and 9.6% of the total propane/air mixture must be propane in order for it to be combustible. If the mixture is 2% propane and 98% air, there will not be combustion. If the mixture 10% propane and 90% air, combustion will not occur. Any percentage of propane in a propane/air mixture between 2.15% and 9.6% will be sufficient for propane to burn. However, an improper air/gas mixture can produce Carbon Monoxide (CO) that is a deadly product of incomplete combustion.Flash Point - The flash point is the minimum temperature at which propane will burn on its own after having been ignited. This number states that below -156°F, propane will stop burning on it's own. In other words, if the outside air temperature is -155°F, propane will burn on it's own. If the outside air temperature falls to -157°F, propane will no longer burn on it's own. However, if a source of continuous ignition is present, propane will burn below - 156°F.Ignition Temperate in Air - This number states that propane will ignite if it reaches a temperature between 920-1020°F. If propane is heated up to a temperature between 920 and 1020°F, it will ignite without needing a spark or flame. Taken from this document... http://www.propane101.com/aboutpropane.htm Any time you can prevent the propane/air mixture from reaching ideal ignition point, you are "probably" safe.... Some thing as simply as removing valve from tank ... Be sure its empty first - New OPD valve have a no-flow valve that if there is not a regulator or connector fitted to valve outlet there is no release of gas.... By simply putting a hose from air compressor into valve "hole" (not connected, just freely inserted) and saturate inside of tank with a free flow of air, to upset the fuel/air ratio (ignition point) can prevent explosion....Maybe CO2 or nitrogen would be safer, but all you are doing is upsetting the chemical balance of the ignition point of the propane.... DISCLAIMER: Please do not hold me responsible if you have accident, and you did not do your own research to prove me right or wrong.... The information you need it out there .. YOU have to do independent research for yourself till you are comfortable with process.... Dale Quote Link to comment Share on other sites More sharing options...
waianvil Posted March 13, 2013 Share Posted March 13, 2013 have you check out fire extengisher busness they have co2 tanks that what I used and they are real cheap to buy Quote Link to comment Share on other sites More sharing options...
Danny C Posted March 28, 2013 Share Posted March 28, 2013 We cut quite a few for BBQ pits in our shop, anywhere from 50 to 500 gal tanks. safest way to cut it 50# co2 remove the tank fittings small regulated hose from co2 to tank fitting holes fill the propane tank till sniffer says safe or carefully fan a top opening until you get a whiff of the co2, caution it will burn/irritate your nose if you get to much. The co2 is heavier than air so when it comes out the top your tank is full of a non combustible gas, put the torch to it and feel 100% safe, Have never had a problem doing this but did pop a 25 gal full of water once, That will scare the daylites out of you if you are still in one piece Quote Link to comment Share on other sites More sharing options...
Gazz Posted March 31, 2013 Share Posted March 31, 2013 I have cut many of the older ones with no problems. Open the valve and turn it upside down and leave someplace where the sun can work on it. Propane is heavier than air and the heat from the sun expands whatever gas is in it and drives it out. When the sun goes down, the bottle cools and draws fresh air into it. The next sunny day repeats the process and after several days, you have respirated all the flammable gas from it. When I am ready to cut, I heat the bottle with a rosebud and occasionally I run the flame by the open valve. If there is any flammable gas in it, it, it will ignite and burn briefly. If it does not light, there is no flammable gas in it. If it is a newer bottle you want to cut, a fitting needs to be screwed into the valve as the new valves need a proper kind of fitting screwed in to activate the safety valve while it sits in the sun and respirates. Quote Link to comment Share on other sites More sharing options...
BobL Posted May 3, 2013 Share Posted May 3, 2013 I realize this is an old thread but thought I would add my experience on opening up a 10 gallon gas cylinder. It took a fair bit of effort but eventually I got the valve off. Tipping it upside down and a handful of rust fell out that had a faint odour of mercaptan (the smelly oil they add so that gas can be smelled) Then I filled it up with water and left it in the sun all day and then tipped the water out. I did this at least 5 times. Then I cut it open at one end with a thin kerf cutting wheel - no problem. The steel was 1/8th"thick and encrusted with a 1/16" layer of rust Then I cut the other end - this was through a weld - I had gone half way when there was a small woof and a flash of flame from the open end. What I suspect happened was even after what I did there was still a small pocket of gas trapped either in the weld or rust. Quote Link to comment Share on other sites More sharing options...
Frosty Posted May 3, 2013 Share Posted May 3, 2013 The cutting disk heated the mercaptan oil past it's flash point and you got a pop. No big danger, it's pretty low power. Next time mix a cup of chlorox bleach in the water and it'll neutralize the mercaptan and it'll flush right out. Multiple flushes don't do much of anything for propane, it's so volatile it doesn't hang around. One flush will purge the tank well below a flammable level, getting rid of the mercaptan is a higher priority at that point, it stinks. Frosty the Lucky Quote Link to comment Share on other sites More sharing options...
BobL Posted May 3, 2013 Share Posted May 3, 2013 The cutting disk heated the mercaptan oil past it's flash point and you got a pop. No big danger, it's pretty low power. Next time mix a cup of chlorox bleach in the water and it'll neutralize the mercaptan and it'll flush right out. Multiple flushes don't do much of anything for propane, it's so volatile it doesn't hang around. One flush will purge the tank well below a flammable level, getting rid of the mercaptan is a higher priority at that point, it stinks. Thanks for the info. While I agree your explanation sounds more likely it is worth noting I could not smell any mercaptan after flushing or when I cut the first end of of the tank off. Quote Link to comment Share on other sites More sharing options...
Frosty Posted May 3, 2013 Share Posted May 3, 2013 Rust can hold all kinds of stuff, it makes cutting ANY fuel oil tank VERY VERY dangerous. The cutting disk probably heated the rust on the other side enough to cook off the oil and a spark lit it. It was a pop right not a BOOM or even BANG. What I found was the welding shops who do oil tanks steam them for days and do the hot work with the steam going full blast. When I asked they told me the steam drives any air out of the tank so it can't ignite. If you do this much you get to where you just ignore pops and bangs. BOOM? . . . Probably won't suffer or remember. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
BobL Posted May 3, 2013 Share Posted May 3, 2013 Rust can hold all kinds of stuff, it makes cutting ANY fuel oil tank VERY VERY dangerous. The cutting disk probably heated the rust on the other side enough to cook off the oil and a spark lit it. It was a pop right not a BOOM or even BANG. Yep - a small woof. It reminded me of igniting hydrogen in a test tube Quote Link to comment Share on other sites More sharing options...
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