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Welding Angle Iron. Travel angles beyond 20 to 25 degrees can lead to more spatter less penetration and general arc instability. When you clamp it to a piece of box use a box section with a large radius on the corner this will clear the radius in the corner of the angle iron.
If angle iron has no curve when laid on flat surface it should be okay to use. Short pieces of angle iron are placed the entire length of the parallel pieces forming alternate V shapes. By welding the angle iron to the metal frame structure it will provide not just strength but also make the workspace look smooth and neat and helps avoid the possibility of the pieces coming apart because they will be joint together.
If angle iron has no curve when laid on flat surface it should be okay to use.
Also angle iron is weakest in position you described. If angle iron has no curve when laid on flat surface it should be okay to use. Also angle iron is weakest in position you described. Tools to Use When Welding With Angle Iron Welding Machines.