I've Got Gas

It was going to happen eventually...I finally encountered some bolts that simply wouldn't budge.  Years of rain, grit and grime basically fused the nuts and bolts securing the truck's rear fenders. To get them off, I had two options...use a nut splitter (an inexpensive hand tool which I don't currently own but have since ordered) or torch them.  My buddy Jim happens to own an acetylene torch and was kind enough to bring it over to my place so we opted for the later method of removal.

About 8 years ago, I attended a few basic welding classes at a local community college and got to use an acetylene torch.  Despite this experience, I never really understood how this device actually worked (beyond the basic premise that the torch "melts" the metal).  To improve my understanding, I did a little reading.  As one might surmise, an acetylene torch uses a mixture of oxygen (pure 100% oxygen as opposed to the air we breath, which is about 20% oxygen) and acetylene.  Pure oxygen allows for a higher flame temperature.  For an idea of how much higher, use your BBQ gas grill as a point of reference.  A traditional gas grill uses a propane/air mixed flame that burns at about 3,600 degrees Fahrenheit while a pure oxygen/acetylene flame burns almost twice as hot (about 6,300 degrees Fahrenheit).  When used for cutting, the oxy-acetylene torch basically heats the metal to an unstable state and forms a thin layer of iron oxide.  A quick blast of oxygen (controlled by a trigger on the torch) then super-heats this surface layer of iron oxide which in turn cuts the metal (this happens because Iron oxide has a much, much higher melting point than most metals).  In other words, its the iron oxide that does the cutting, not the torch.  The brief oxygen blast also helps push the melted metal out of the cut.
 

From a practical standpoint, there are flow valves at the base of the torch that enable titration of how much oxygen bleeds into the flame.  You then heat the target (which in this case are the bolts securing the rear fenders) until they become cherry red, then you squeeze the oxygen trigger and Voila...bye-bye bolt.  When its all said and done, it takes about 5-15 seconds to obliterate each bolt.  As you can see from the photo below, the process is not unlike me on the beach in the summer--lots of sparks, smoke, and some burn marks (did I mention I'm a pale-skinned ginger?).

Jim showing me how its done

The best part of using the torch (aside from it saving a butt load of time & effort) is that you get to wear cool-dude shades like the guys on all those Discovery TV shows.

With the fenders off, my next step will be to remove the bed and start sandblasting the frame.  I'd also like to remove the cab from the frame so I can blast and prep the entire frame, but I'm not sure I have the space yet (my wife doesn't start parking in the driveway until September) or equipment (no overhead hoist, no rafters to use, etc).  I'll make a definitive decision once I get the bed off.