Gluing, welding or screws??

Hello guys, I plan to build a roof support for my camper (Mercedes Sprinter – high roof). 6 feet made of galvanized 4-kant tube should provide the basis for 3 traverses. Since the camper is already isolated from the inside and I don’t want to drill so much I wanted to ask what do you think about it if I stick the feet with Sikaflex 260 or similar stuff? Epoxy resin or n glue from Jowat might be an alternative. these super glues are an alternative to welding in terms of durability. Thank you for your answers… LG Carsten