Remove Undercoating
I just remembered when I did my '68 GTX about 28 years ago. I started it in winter (on Long Island). I remember using a paint scraper and a hammer and the stuff popped off in chunks. You guys jogged my memory of that experience. That was when no body panel re-pops were available and I had to hand-form all the patch panels from sheet steel. UGH!
Anyway, because I now live in Hell (temperature-wise), it will never get that cold for me to have the same undercoat removal experience. As the saying goes, "Ya gotta do what ya gotta do."