Well, "real welders" do crazier things than that. About 500 yards from my back door, there was a bad train wreck in 1991. 30 cars went off the track, and made a real mess. There was a carload of 120,000 lbs of sugar that made a puddle that is still attracting bees. There was a carload of autos that were crunched into paperwads. Another carload of 2x4's turned into toothpicks. But the big problem was 4 carloads of white phosphorus. This stuff is shipped in sealed tank cars, because if it meets with oxygen or water it IMMEDIATELY bursts into flame. They exacuated everybody within 2 miles of the thing. I was out of town glued to a TV set watching my farm get blown up. Some of the phosphorus tank cars were cracked, letting in just a little air and dumping their contents to burn. the solution was to dump truckloads of sand on the cars, but eventually they had to seal them up so they could be removed. So some POOR SCHMO REAL WELDER had to weld up the crack. They paid this guy some astronomical sum. They had fire departments from four counties standing behind him with foam trucks, and four dumptrucks with beds raised and 13 tons of sand in each, ready to dump. Fortunately, the rolling bombs did not ignite when he welded them sucessfully. The rest of that summer, a dozer drove back and forth across where the mess had been, pulling a big plow. Every once in a while, a little more phosporus would pop up and begin burning, and a standby hazmat team came in a scooped it up. I packed out several hundred pounds of big gauge steel (with permission of course) then the demolition crews were in cutting the twisted cars apart. What a find! --Lawrence ----- Original Message ----- From: "John Ferrell" To: Sent: Tuesday, June 25, 2002 8:17 PM Subject: Re: [OT]: RE: [EE]: Fuel tank sensor / real world solutions > The old fashioned remedy was to run a hose from a running engine into the > tank and purge it with Carbon Monoxide while you welded it. I never heard of > a "real welder" who was willing to do it that way though. I certainly would > not. > > I have been known to make a few puddles and I don't consider myself a welder > BUT I doubt the validity of welding a tank filled with water. I think the > water/steam will cool the metal too much to work. Of course, if you do a > good job of sealing it up you are in for a certainly lethal steam explosion. > Like the US Army reactor in the late 50's that suffered a power excursion > resulting in a deadly steam explosion in Idaho. I was a Lab tech at a small > research reactor at the time. Steam is as dangerous as any other form of > energy! > > ----- Original Message ----- > From: "Pic Dude" > To: > Sent: Tuesday, June 25, 2002 7:31 PM > Subject: Re: [OT]: RE: [EE]: Fuel tank sensor / real world solutions > > > > Many years ago, I needed to move the filler hole on > > a fuel tank and my local welder wouldn't touch it. > > The idea I came up with to totally eliminate the fuel > > residue was to use a model-rocket ignitor and ignition > > system, and just light the tank up from afar in a big > > open space to burn off any traces of fuel. > > > > Of course I'm not stupid enough to try this, but wonder > > if it would be practical with some form of inert gas to > > slow down the burn rate and make it burn rather than > > explode. > > > > Usual disclaimers, etc apply to anything stated here. > > > > Cheers, > > -Neil. > > > > > > > > > > -----Original Message----- > > From: pic microcontroller discussion list > > [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Andrew Warren > > Sent: Tuesday, June 25, 2002 5:48 PM > > To: PICLIST@MITVMA.MIT.EDU > > Subject: Re: [OT]: RE: [EE]: Fuel tank sensor / real world solutions > > > > > > Spehro Pefhany wrote: > > > > > > Don't think I will try, but according to the instructor, > > > > you can weld tanks which have already had fuel in them, > > > > by filling them with water. > > > > > > I've heard of steam cleaning plus filling them with CO2. > > > > Seems like a lot of trouble; the only method I've ever seen is > > the one previously mentioned (filling the tank with water). > > > > I've never met ANYONE who likes welding on fuel tanks, even when > > the tanks are filled with water; I can't imagine a welder being > > comfortable working on a tank filled with an invisible gas. > > > > -Andy > > > > === Andrew Warren -- aiw@cypress.com > > === Principal Design Engineer > > === Cypress Semiconductor Corporation > > === > > === Opinions expressed above do not > > === necessarily represent those of > > === Cypress Semiconductor Corporation > > > > -- > > http://www.piclist.com hint: To leave the PICList > > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > > > -- > > http://www.piclist.com hint: To leave the PICList > > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > > > > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu