Renze
Super Member
We would weld the first part onto it, then use a sledge to bend them tightly over the I beam. Then use a clamp to hold it in position so it wont spring back.
On the inner of a gooseneck we bent them also with preheating of a torch, in a workbench vise grip. Then the occasional sledge blow to make it fit perfectly and clamp it.
On stepped chassis (deck above the 5th wheel about 105cm high, low deck 65 to 80 cm high, depending on tire size) we usually took a longer flatbar (or strip, whatever you call it) that would overlap both welding joints of the uprights.
It doesnt matter if the bend in the edge isnt exactly square, a little half inch radius caused by manual or vise grip bending of the flatbar, will only help to prevent peak stresses to occur.