i had to weld a mild 1/8 steel shell, seam weld to 100% using .045 flux, the shell about 50 inches diameter 4' long, it came in rolled already, thier was no gap and the surfaces had scale and rust, they wanted the shell cleaned and beveled out on the inside and welded, than grinding out the outside and welded. In following this I ended up having more garbage to grind out than weld, now if it where left up to me, I would have seperated the shell cleaned it up and re-attach it leaving a .045 gap and welded it inside than grinding out the back side and weld, I detest too much grinding, and repeative weld and grinding is nearly intollerable, not to clean the surfaces before rolling makes me wonder, any other imput would be grand