Can't help with your baloon sander - sounds like it would be a neat
device. Perhaps small drum sanders in a Dremel tool or (or larger)
would do the trick. For example,
http://woodworker.com/cgi-bin/FULLPR...?PARTNUM=23689



dean wrote:
I think I saw somewhere an inflatable sander that could flex around
and inside curves, may have been on the end of a drill but I think it
had an air supply continuously pressurizing the system. Anyone know
what this contraption is called or how it runs?

If not, how best to sand a load of wooden octagonal rails, 6" apart? I
want to smooth them over after presure washing, to take the splinters
out and make it smooth.