Hello,
Having refinished only a shk which is primarily wood construction with fiberglass cockpit and leading edges, IMHO if you decide to purchase a pneumatic (air) driven sander, dual action orbital or "air file" there is a world of difference between quality tools and Harbor freight cheap imports.
I recomend Hutchins brand tools, powerful, smooth action, and easy on air demand. also you can use a water flood with air tools.

For heavens sake wear a high quality air mask, that previous comment of not needing one because the particles are too big is B.S. and dangerous!
As an ICU RN I work with pulmonologists every day and ran that one by them, one simply stated "I wouldn't breath that with your lungs"

As far as time required, I removed three complete top coats of paint (about 75 lbs worth) and primers and fillers. brought up the new coatings and used polyurethane top coat, 18 meter wings, 4 foot wing root, big constant taper fuse, about 1100 hours.
B.T.W. prestec products ROCK!
Good luck and best wishes!
Scott W.