A car in need of a complete rework of its paint will typically need its existing paint to be removed.
If you want the job done right then you'll have to start from the beginning, making sure each step along the way is performed correctly. Larry Kosilla, the man behind the Ammo NYC car care brand, understands this completely, which is why he's taken great care to make sure his own Porsche 911 is treated properly.
Larry has documented the process of restoring his 964-generation 911 on his YouTube channel. It makes for a fascinating watch, because the videos take a deep dive into the work being performed. Larry wanted to clean his car up completely, and to someone with a fanatical eye for detail that means a lot of work will be involved.
In order to achieve the level of quality Larry wants, especially on a car painted black, the original paint needs to come all the way off. Stripping paint is a gruesome process for those of you who like a nice finish. For those of you who enjoy seeing chemicals doing their job though, you're going to love the video above.
Body panels are removed from the car and then taped off where necessary. After that, aircraft-grade paint remover is applied and then covered for a bit to both retain fumes in place and speed up the process. Other parts are sanded and fixed because portions of the car needed more serious attention.
Once the paint remover has been allowed to sit for awhile, the cover is removed. From there, the paint is scraped right off. In fact, the paint stripper is so powerful that much of the older black paint pops and ripples off the bodywork all on its own. It takes more than one round to get all of the paint off, but that's a credit to the prior paint job applied in the past.