The extrusion shape is a simple square tube. If I set it down on a perfectly flat surface with its curvature upwards, the middle raises up by around 5mm over the length of 1m.
So far I tried to just put a weight on it while its laying on a glass pane (my perfectly flat surface) but after 24h that did just about nothing.. maybe if I left it there for a year? I'm not that patient.
Are there any other options for me to straighten it without specialized tools? I could heat it up with a torch if that helps..?