Recently I re-started work on my closed cab pickup project. The design requires that I lengthen the chassis by 5 inches, which means a bunch of other stuff needs to be lengthened as well.
This week I have been working on lengthening the running board splash aprons. Over the years I acquired 3 sets of aprons, all of them beat up but more or less salvageable. Splicing the aprons together required a set of butt clamps to hold the pieces in alignment for welding. A quick online search showed me what I needed and since I had the raw materials lying around I decided I could make a set to suit my purpose. I used 1 ¼" square tubing, ¼” bolts and rod, and some stamp sized pieces of sheet metal that I cut from the splash aprons I was working on.
The bolt heads were slotted with a hack saw and the bolts and tabs tacked with a MIG welder. Commercial butt clamps use a square pin. I found the round pins made fabrication easier and they work well when clamping curved pieces.