Parasitic drag question

Well, maybe a bit more than a nit. It takes about 400 hours to smooth
a 100 sq ft glider wing to the tolerances needed.

In article , "Morgans"
wrote:

"d b" wrote in message
hlink.net...
paint adds zilch, nada, nothing. Smooth means a lot, but you
can't get smooth by painting. It takes sanding of the paint (or gel coat)
until the divits and lumps do not exceed .003 +_ inches in a 2 inch arc.
For most power type planes, lumps and bumps don't mean anything
behind about 20 or 30 percent chord in any case.

Agreed. Given that most people sand and fill when they paint, I was
thinking the painting process was going to make it smoother, as you suggest.

Any other nits to pick?

Hi Group, lost my identity somehow when the computer locked up so to reply
to all the good imput you have made I have had to make a new one.
The manufactireres and my plane is almost identical with a ground adjustable
prop (Bolly 3 blade) Same fire wall forward kit..identical. Both climb and
top speed are down so suspect the pitch is not the answer, I may be 10kg
heavier though.
Interesting to hear the concensus that the paint will make very little
diference so will have to put my faith in the four last bits of fairing
(front wheel pant and three leg fairings around 1 1/4inch tube) I like the
coment "Manufacturers ALWAYS achieve better performance than their
customers. It's a fundamental law of aerodynamics". Thanks for that and all
the other comments. Derek.




"Derek Anderson" wrote in message
...
We are currently test flying an all fiber-glass experimental plane in an
unpainted state and wondered if any of you have done the same and
experienced as much as a 10% increase in air speed and improved climb rate
after painting your planes.
I know most of you are happy to wait until your pride and joy is painted
but
we opted to test fly in the raw. The manufacturer who has a similar plane
is
achieving around 10 knots better speed for the same revolutions, at 4,600
rpm on a Subaru conversion with a 2:1 reduction he gets 100 knots and we
are
only just getting 90. The only difference in configuration is the addition
of front wheel fairing and three leg fairings plus nice shiny paint. Our
climb rate is also very low compared to predictions. It will be several
months before it is painted and back in the air so am asking the group.
Replies appreciated. Derek.