I primed the parts of the rear spar assembly today, well only on one side, then I ran out of primer, I've got a more on order. Since I was only going to use the grey self etching primer on the inside of the airplane (for aesthetic reasons), I'm back to using the ugly green aviation grade primer, I don’t think it makes too much of a difference since the 6061 grade aluminium is not very prone to corrosion but these parts will be more exposed to the elements than the inside of the cabin so it’s probably best to use the good aviation primer.
