Wayne, like you, I scrapped most of the "crud" off, then sprayed several cans of Oven Cleaner on the frame.
Let it sit 15 or so minutes, then take the water hose to it. ( A pressure washer would be ideal!)
It takes it all off, including paint and primer!
Be SURE to wear eye protection! This stuff is caustic, and will eat skin! - I know, I was wearing shorts, and didn't feel it on my skin, till I started burning!
Again...wear EYE Protection, one stray gust of wind, a little overspray in your eye, and it's BAD news. Good Luck!
