Setting the top longeron perfectly horizontal and vertically aligned required cutting 4 jigging timbers of equal length and securing them to the workbench with angle iron. The top longeron is coped to the tail post but not welded. It had to be aligned vertically above the centre longeron marked on the workbench. This was done using a plumb bob before securing the longeron with plumbing straps . The laptop and a coffee are never far away. The Pandora playlist varies hugely and is always playing. From 1930s Robert Johnson blues to Pink Floyd, classical music is all I can listen to when welding. The focus and precision of both these art forms go hand in hand for me.
I have become more comfortable using the flapping disk freehand and without templates to cope the tube ends which meet at the clusters. When happy with the top and bottom ends, the tube is held in place with duct tape so it can be tack welded. It's important to preheat the cluster before welding.