A huge amount of time went into deciding where to put these common sump hard points. It is reasonable to know where the pipes are all going before you place the permanent termination points in place?
I'm using 2024-T3 1/4" thick aluminium. Three points are tapped for the 3/8 or -6 pipes I'll be using for fuel lines and vents. These will be in 5052-0 AL tube probably 0.035" ID wall and 3/8 OD (0.375")
I've made provision for the fittings by tapping them out. One of these will be a low fuel sensor and I have a 1/4 NPT tap coming in the mail so that may have to be finished off after the tank sides are in place. I have dilled it up as far as I can go.
I've dremmelled out cavities and I'll flox them in place, glass over and retap later.
