So you’ve got your welder, a saw to cut metal, and a stack of tubing you want to make into something. It doesn’t matter whether it is a table frame for your house, a back half chassis section for your hot rod, or some special project the spouse put you on. Regardless of what it is, if you need it to be true and flat then this can work for you. If you have every tried welding a frame of tubing together on your garage floor, then you’ve had some issues with getting this flat and straight. Unless you have a perfect brand new garage floor, and even then it might not be as flat as you think, then this is going to come in handy. And there is no reason you can’t use this method on a workbench or table either. You’ll see what I mean when you watch this video from Fireball Tools. It works, it’s simple, and it makes so much sense after you see it.
But why does it work so well? In the video you’ll get a concise explanation, but the biggest and most important thing to remember is that a plane, as in geometry, is always flat and is always defined by three points. You can’t make a plane with anything less than three points and for each point over three the creation of a plane gets more and more difficult. So if you use three then you can make a really flat plane out of your material and insure that your project turns out just right instead of almost straight.