[Hope Springs Hauler]

It's one of the original methods. It takes a steady hand. It can use but does not require the use of filler like arc or mig. In general terms, you are melting the two pieces into a single puddle.

I am more of the opinion that body work is a MIG process rather than oxy-acetelyne. MIG allows for a distribution of heat and reducing warpage in thin materials. Oxy process requires the concentration of heat.

Oxy-acetelyne can be used to join pieces of great thickness and is a good tool to have. My welding instructor taught that first to teach weld puddle control. Then we moved to arc, mig and tig.

My personal experience is that I wouldn't try anything but mig on sheet metal.