Originally Posted by HAL Pilot
I have seen some builder logs where only the mating surfaces are coated. But that's a subject probably for the primer Wars ;-) I don't have an opinion on it yet just the input.
I have no interest in the primer wars, thankfully. It probably makes no appreciable difference whether I prime the mating surfaces of the spars and spar doublers or just the exposed surfaces after mating the parts, but as long as it's not a thickness concern where two layers of primer cause the vertical stabilizer not to fit onto the airframe, I'll be okay.