PaulMarcel said:
The heat gun, though, once to temperature will make quick work of softening up the paint for the scraper. Handy, too, that the scraped off paint can just fall down since you're scraping above you.
Heat guns are slow, if you go the route of scraping the paint away, for a large project I'd use a real methane/propane burner instead. Bit riskier but also a lot faster. Keep a bucket of water or an extinguisher at hand. I also keep a plant sprayer in reach, works best for me.
The fact that you work above your head is not handy at all, everything will fall down on you, preferably in your eyes. Removing paint above your head is a truly rotten job and worthy of an episode in Mike Rowe's Dirty Jobs. To make it a bit more bareable I use a full face screen which I highly recommend to anybody doing this kind of job.
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What I think works best in this application is not a sander but the
Metabo LF724 paint remover. It's basically a router with a very low depth setting (measured in micro meters) so you won't be sanding the paint away but cutting it away. It works very fast and with a connected vac you can control the dust reasonably well. If you're used to Festool prices, it's pretty cheap also.
If it HAS to be the Festool route for you, the RAS115 is of course the best choice with the RO150 a good second. If you're the Hulk you could even consider the RAS 180 since it's a large project, but for us mere mortals that beast would wear you out quite quickly working above your head.
The RAS gives you the fastest paint removal of any Festool sander, and the 115 is a pretty light machine so it will do nicely when working above your head. Forget about any dust control though when working above your head, it's impossible with a sander, even a Festool. You will find yourself covered in dust from top to toe.
Don't worry about the heat built up PaulMarcel is talking about, it is really not a problem with the oil based paints we use here in Europe outdoors.
But I'd go for the Metabo LF724, works fastest and cleanest.
After you've done the rough paint removal, whether you use the LF724 or the RAS 115, you can clean up with the ETS150 or the DTS400.