So when sanding a 19 ft Southwester one will expirement with every available type of sanding instrument, device, tool, etc....
That being stated, I am having great success with this cheap little tool I devised.
Its just a cheap dremel with a right angle attachment with a 1 inch sanding pad. Its great for getting into tight little areas. Instead of buying the precut sanding discs I just draw a bunch on bulk sandpaper and cut them out.
https://www.dremel.com/en_US/products/-/show-product/tools/dremel-4300
https://www.dremel.com/en_US/products/-/show-product/tools/575-right-angle-attachment
https://www.woodworkingshop.com/search.aspx?q=fp25100