well ive been trying to roll 3mm flat steel into a half circle
and I know ive seen it on this forum someone using a wagon rachet and gas bottles to do it
well ive tried it and what a swine it is to do ended up putting it in the vice to get some shape then was able to roll it much better around them just dropping gas bottles sizes to do it
by hand is not easy to do but it will do it
im now making it much smaller by using the telegraph pole to make it even smaller in size but to shape it right at the start was hard work and im only rolling 3mm x 660mm
its taken me a good few hrs to get a 7" deep x 10 1/2" wide and ive still got to close it up more