Well, not what I had in my head, but it is working well !
Got a simple sprayer & took a couple parts off the nozzle , hook a hose & length of (new) brake line.
I set up the same on the air gun.
With the car on it's side so the POR 15 will run down the seam. Use 25 lbs air to force into the seam.
Started in the middle & down.
I'll rotate the car to do the other half - windshield side first. Front of inside cowl will be done after the back is done & dry.
It's all I could come up with , after visiting Bumpers , NAPA & other stores.