"Discus 44" wrote in message
ups.com...


Anyway I was just curious if there was a secret competition reason for
roughing the surface to keep the airflow attached longer than a shiny
smooth surface would give.


There is research to suggest that a slightly rough surface will keep airflow
attached a bit longer than a mirror smooth surface. I've flown wings sanded
with various grits from 400 to 2000 and find no difference in performance.
Stopping at 400 grit is a LOT less work than continuing to 2000. The REAL
reason for a mirror surface is that it's a lot easier to keep clean.

That said, I've always suspect that the "sand your wings" suggestion came
from a well known competitor trying to mess with another competitors head.
80 grit anyone?

Bill Daniels