I have many situations where I have circular hollow sections (say 100mm Diameter) that have been rolled into say a 10m radius, which I have to attach cleats to them. The cleats are like an extruded letter "D'' and it is the vertical side of the "D" that I want mated to the the outside of the rolled tube. The mating face of the cleat is say 75mm x 8mm and flat. I can mate each corner of the face to the outside of the hollow section and put it at any angle by mating the side of the cleat to a plane, BUT it often (read mostly) wants to flip into the inside of the hollow section on the otherside. PLEASE has anybody got a solution to this?