TIL that switching from a 4-inch to a 2-inch backing strip on a 3/8-inch plate weld made a huge difference.
I was on a job in Toledo last month, and the foreman insisted we use the narrower strip on a boiler patch. I thought it was a waste of time and material. Over two full days of welding, the heat input dropped noticeably, and the distortion on the 8-foot seam was maybe half of what I'm used to. It took a bit longer to set up, but the fit-up was way easier and the final inspection passed on the first try. Has anyone else tried this on thicker plate and seen similar results, or was this just a lucky one-off?