Dave, I'm doing the same; it was #6 in the PPG advice, sans the DPS3055 sanding sealer which we don't need. Appreciate your RV-9A report.
I was also unhappy with DX1791 adhesion. Early on I shot a seat back, got a run, and elected to strip and start over. It came off way too easy, often in sheets, and all I used was a water hose and scotchbrite.
Dan,
I've noticed that the DX1791 improves with time (wine??). A day or two after shooting it will be really soft and not well adhered (over alcad) but will firm up and become much tougher over time. Still won't adhere great though unless scuffed. I used it inside just to bring a little zinc to the surfaces. Probably a waste of time really. The sherwin williams wash primer that I used inside of my RV-9A seemed much better. Should have stayed with it.
I also have a real problem with the etch/alodine system. I know it's been around forever but what happens after the aircraft is built and ready for the paint shop. The etch has to be thoroughly flushed with water as its corrosive. I wonder how the etch and alodine chemicals affect wires and electronics that it may get into. With a high quality self etching primer this is not a problem. I called several A&P friends and both said the acid etch must be flushed throughly from all crackes and crevices or it will actually cause corossion. Can anyone with experience with the etch and alodine primer system weigh in here.
Dan,
I've noticed that the DX1791 improves with time (wine??). A day or two after shooting it will be really soft and not well adhered (over alcad) but will firm up and become much tougher over time.