Once upon a time I heard a rumor that acetylene tanks were full of acetone which made them really heavy, like they weren't heavy enough all ready. Supposedly you could store more acetylene by dissolving it in acetone than you could by just pumping it into the tank.
Today (two weeks ago actually) we were over at Jack's house using his oxy-acetylene torch to remove the previously mentioned uncooperative bolts from the exhaust header, and Jack mentions that acetylene tanks are full of balsa wood because acetylene is explosive under pressure. Okay, that explosive bit is weird, but back up just a second. How you could weld a steel tank around a big chunk of balsa-wood without burning it to bits?
All these rumors got me curious about acetylene, so I looked it up on Wikipedia, and found some very interesting stuff. I collected the interesting bits on a single page for your reading pleasure.
We tried just heating up the broken bolts and then drilling, but we had no better results than John and I got the other day using a propane torch. Next we tried an E-Z-Out, because Jack had some, but that went nowhere. Then we got out the cutting torch and burned out the remains of the bolts.
Cutting with a torch is a tricky business. It requires a steady hand and the ability to understand what you see. I think both of these come from practice, and I haven't used a torch since I don't know when, so I was a little rusty. I got the job done with destroying the flange, so good enough.
When you are cutting, you are looking through very dark glasses. This is to protect your eyes from the very bright light of the oxy-acetylene flame. But what you really want to see is the steel, which to start with is only illuminated by the light from the torch. But it quickly starts to glow red, and this red light is your clue as to what is going on. Do you have a big enough puddle to start cutting? Or is that only a fragment hanging in the flame? Pushing the go button too soon and your cut won't start. When the cut does start you have to be Johnny-on-spot, ready to start moving the torch in the direction you want to cut. Mistime that and you simply get a small notch and get to start the heating portion all over. It takes practice to be any good at it.
Jack's father worked in the shipyards during WWII cutting steel with a torch, 8 hours a day, five days a week for four years. The thickest thing he ever cut was a 24 inch diameter propeller shaft.
P.S. Google Documents has forgotten how to format a page of text to display on a computer screen, so I stuffed my acetylene story on my new-ish Google web page.
P.P.S. ahab showed me a trick to display Google Documents. So here's the link if you want the printer-ready layout.