Did you take shop class in Junior High School? Back in the days of adequate public school funding and less emphasis on college preparation, young men were given instruction in the "Manufacturing Arts" and young ladies were taught "Home Economics." Conventional wisdom of the time held that we needed to prepare your youth for their eventual careers: Men on the assembly line and girls at home keeping house. American society has outgrown this quaint anachronism, (although the children's school year is still constructed around a three month summer holiday so the young'uns can be home to help bring in the crop at the family farm). Shop class is now a distant memory for us older folks, kids today are more likely to get a computer arts class that is certainly more relevant to today's job market. Which is kind of a shame since the basic skills learned in shop class are important to the At Home Mechanic.
We learned in Wood Shop how to appreciate the danger of power tools; at least one kid each year discovered a way to permanently disfigure himself with the band saw. In Metal Shop we learned that making toolboxes was boring, but you could use scrap sheet metal to make your own Ninja Throwing Stars (imagine a palm-sized, star-shaped Frisbee, used for teen-aged mischief), which would be confiscated if found by the shop teacher.
But we also learned how to use hand tools, the importance of measuring carefully twice so that we only needed to cut once and we gained confidence in fabricating something from raw materials as opposed to assembling form a kit of pre-formed parts. Fabrication is to assembly from a kit as free hand painting is to paint by numbers.
There is eventually come a time in the garage when the "guaranteed to fit" parts may not or you will be forced to make what you need on your own because no one sells that kind of part for your car. Those fabrication skills will serve you well in this situation. I take pride in being able to define a problem and then design a solution using scrap metal and my imagination. A garage vice, a ball peen hammer and a hacksaw have served my needs well.
I created a front air dam for a 1958 VW Beetle using sheet metal, a hand drill and some screws. I made a new set of seat supports for a 1966 Mustang using a hacksaw and some angle iron. And I have fab'ed a Cold Air Intake for my 1987 Honda CRX from some PCV plumbing supplies. While none of these items will ever earn a design award, they are perfectly functional. And I was able to make them from raw materials because I had the experience of building stuff from scratch that dates back to Junior High School shop class.
My next fabrication project is also for the '87 CRX. I am going to remove the power sunroof and all of its associated mechanism from the car and I need something to fill the hole that will be left in the roof. I could just screw down a sheet of metal over the hole, but that offend s my aesthetic sensibilities, I want something that looks as if I made an effort to creatively solve this problem. So I will be doing some fabricating to make a slick filler for the resulting hole and I will be posting the process in the coming days.