Pics of a flexible  sanding block.
Appalled by the high cost of large
flexible sanding blocks, I made this
one from a typing wrist support pad
and a piece of computer packing foam.
The green pad is a very dense foam, and
is perfect for contour sanding. I glued the parts
together with white glue.The pad surface measures
2-3/4" X 18-1/2". 
For the retaining clip bases, I used some 22GA steel
from an old cookie sheet. The retaining clips are 
standard heavy duty paper clips. Originally, I attempted
to spot weld one of the release levers to the clip
base, but the high carbon steel of the lever just
burned through with a shower of sparks.  With
classic out-of-the-box thinking, I passed a section 
of coat hanger through one of the eyelets and spot
welded that to the base. Perfect.
The bases are glued to the pad with epoxy.
This sanding pad is for final primer finish on my
Datsun Roadster project.
Questions/comments:
jasonrnorth@bigfoot.com