I have an old propane tank that I want to turn into a gas forge.
I have the burner, gauge, regulator, and hose. All I need is to fabricated the forge.
My plan was to get the valve off the tank and let it sit outside for a couple of days, then rinse it out with water, and take a cutting disk and/or torch to it. However, I can't get the dang valve off it.
Should I try penetrating oil to loosen the threads? Should I punch a hole in it with a centre punch or something?
I really do NOT want to send myself (or anyone else) into oblivion. So before I do something, I wanted to see if anyone here has successfully accomplished similar.
-- As Iron Sharpens Iron, So One Man Sharpens Another. Proverbs 27:17
If the valve needs to be off for the tank's new use, then do it. If it's because you think that it has to come off in order to safely cut the tank, it doesn't. I've cut up plenty of tanks by simply doing it - they do not need to be purged! PROVIDING that an O-A torch is NOT used to do the cutting.
A propane tank does not have any oxygen in it, so the propane cannot burn in the tank. It may burn as it comes out the cutting kerf, but very quietly. I once drilled a hole in an empty propane tank and held a match to the hole, to convince my cautious stepson that it was safe. The result was a very languid flame, like a small candle.
Using O-A to cut the tank may introduce oxygen into the tank & be unpleasant. DO NOT DO THIS.
What I do is start the cut with a cut-off disk in an angle grinder and finish with a metal cutting blade in a Sawzall. Very fast.
When somebody says "I do this, and this, and this to clean the tank and I've never had a problem", I believe them. It's just that it's not necessary.
You know it's a compound. I guess Bob was referring to the fact that an OA flame can not only be lean, but a jet of pure oxygen is used to burn through the steel after preheating. It is unlikely that the jet is only the stoichiometric amount (the amount required to combine with the iron to form Fe2O3), there is probably considerable excess, and that's the oxygen he's concerned about.
The weld idle control is often gone on old welders. It isn't really part of the welder, and it isn't really part of the engine either. I am always amazed at how poorly they are designed and how enormous the parts replacement costs are.
I welded with it last night. I'm going to paint the outside vertical surfaces of the channel trailer red as soon as this wind quits. Also some of the International red here and there as per Lincoln color scheme. Then Black gloss for rims, tongue, and a couple of other things. I need to drag it to Vegas, as either the printed circuit board or the high idle/regular idle switch or solenoid isn't working. Did get the info from Lincoln that it runs at 2300 RPM, so can get a tach and run it there until I get the electronics fixed. Need to get a motor manual for the Continental, but they are priced through the roof, and a lot of them are just printouts or copied versions, and fuzzy. I am involved in a stair rail making project at our church right now, so that all will happen in a couple of weeks. It's coming along.
When I first dragged this old gal home, it looked like an ICBM control package. The more I get into it, the more simple it is becoming. I have decided to just get a tach, put a spring on the carburetor linkage, and then cut a link of small chain that I can hook to the spring to attain the right rpm, and use that whenever I weld. I may get fancy and make it a little more than that, but as long as the welding output and the AC output are working fine, I can do without the frills. $75 for diagnosis plus parts could add up to $500 real quick. The tekkie said they can't guarantee fixing it because of the lack of spare parts because of its age. Time to switch to Manual mode.
I do think I'll buy a motor manual, though, just to be sure to get it set right, and in case anything needs tweaking. I'm pretty much going to go around the electronics part. When I can find a person who's versed in such things, I'll probably just have them snip the proper wires.
For $500, I can live with a manual control, and that will buy a lot of rods, lenses, strikers, gloves, tips, markers, soapstones, wraparounds, cur-vo-marks, and all those little goodies we love so much.
I am not going to comment or argue with the science? of this logic but rather with the SAFETY attitude that it expresses.
In the bad old days there were LOTS of people injured and killed as a result of poor practices when welding and cutting on vessels and containers which have held combustible substances. I have done my share of 'hot taps' into 'in service' gas lines and various tank repairs and modifications, and I have lived to tell of them but, I have learned that it is not the expected that bites you but it is the unexpected or unrecognized thing that you were not aware of.
I have turned down lots of requests from customers who wanted me to weld on gas tanks without proper precaution. They always have stories about someone who did it all the time by just filling them with exhaust, but the bottom line is always that they did not want to do the job themselves and they did not want to pay the cost of doing the job safely. It is interesting that the most dangerous requests always seem to involve working with stuff that is not worth very much, or on projects that are also not very valuable or worthwhile.
When attempting to weld on tanks filled with exhaust we are hoping that the engine was operating at 100% combustion efficiency and when we cut into an old scrap propane tank we are hoping that nobody used it as a small carry air tank.
Every winter we get more reports of deaths caused by someone using a torch to thaw the frozen lock on the door of a tool box that contains a leaky torch or fuel gas bottle. This has been occurring for as long as I have been in the trade but it continues to happen regularly.
When we work on big jobs, there are firm safety systems in place to ensure that all work is done in a safe manner. We have layers of safety administration and training and firm policies on how safety issues are to be dealt with. We wear ALL the proper personal protective gear and unsafe practice will earn us a quick ride to the gate. It is when we are working independently or for small gypo operators that we are at the greatest risk as there is constant pressure to do the job as fast and as cheaply as possible and safety is considered just too expensive to pay more than lip service to.
The big jobs have learned from hard experience that 'If you think safety is too expensive, just try having an accident.'
Risk management is not about thinking (or hoping) that you are probably safe, it is about ensuring that you have eliminated ALL the risks that could have harmful consequences.
Always remember Murphy's Law, 'If it can, then it will.' and 'It is easy to cheat death, but death's advantage is that it only has to win once.'
'Be thankful of good luck, but don't count on it.'
Curve-O-Mark is a trade name for a line of pipe tools and especially the common marked wraparounds. I prefer to use a strip of plain heavy rubber covered gasket material for wraparound marking (cut from a big roll on a major pipe construction job, not commonly available locally from small suppliers) but many people use the more widely available branded wraps from curve-o-mark. They also make handy center punch protractors and flange tools but IMHO the handiest is their 'contour marker'
Google "curve-o-mark" "contour marker"
This is probably the best (and most essential) welders tool for doing layout of pipe and (with the structural adapter) wide flange and structural shapes. It is not cheap but once you have used one it will seem like a small price to pay for its functionality. It will probably save its cost with saved time and material on the first job. I use the standard size on even bigger jobs by moving it around the pipe or structural shape. They are a little fragile but will last a long time if treated with care.
IMHO this tool and an air powered flux chipper are the most under-used/rated but essential welders tools. IMHO both will be found on the rigs of the most experienced hands, and will also both be absent on most of the rest of the farmers and wanabe's rigs.