Archive for the ‘techshop’ tag
I learned oxyacetylene welding and cutting last week at TechShop
Oxy acetylene cutting torch
I took a class on April 2, 2011 at TechShop in Menlo Park, California to learn oxyacetylene welding and cutting.
I butt welded two pieces of carbon steel together. I only got to try this once, as there were 2 other students and limited time. Liisa, the instructor, gave me millimeter-by-millimeter instruction as I was welding. She’s a good teacher because after the welded steel cooled, we put it into a bench vise and tried to snap apart the weld by banging it hard with a mallet.
It didn’t snap — instead, the metal bent 90 degrees just like it would have if there had been a single piece of steel in the vise. While it wasn’t a pretty weld, it did seem to hold well.
I found oxyacetylene welding to be easier than TiG welding, which I also learned at TechShop, on January 30, 2011.
The really exciting part of the class, however, was learning to cut steel with the torch. On my first try, I cut 3/8″ thick plate steel like it was Jello brand gelatin.
Types of gas torch heads, from Wikipedia.org
Sadly, one can cut only carbon steel with an oxyacetylene torch — stainless steel and aluminum won’t cut. You can melt a crude break in the metal, but that’s not the same as what happens when properly fuel cutting carbon steel, which is the rapid oxidation of the steel in the presence of a lot of pure oxygen. The pressure setting for oxygen when cutting is 25 psi. The oxygen pressure when welding is 2.5 psi, so that should give you an idea of how much more oxygen there is when cutting.
I took the class to learn how to cut metal on my RTS bus conversion. I didn’t know oxyacetylene can’t cut stainless steel. My RTS is nearly all stainless steel. Fortunately, a plasma cutter will cut stainless steel, and TechShop also has a plasma cutter. That’s a different class.
If you’ve ever wanted to weld, don’t be nervous like I was for so many years. Just jump in and take a class. It’s fun!
