Wing Profiling Advice

Andy Blackburn wrote in message ...
Thanks to all for the input and theories. I'm going
to go find/build a wave guage and measure the depth
of all these emerging imperfections and report back
here. My ship arrived with perfect skin, the blemishes
didn't arrive until 'puberty' (age 18-20 months --
this year).

Anybody able to point me to a source and/or plans to
make a wing wave guage?

Thanks!

9B

At 18:18 15 September 2004, John Sinclair wrote:
Larry,
The dimples you see are from holes in the foam core
that allow resin to penetrate the foam and insure a
good bond between the cloth and core. Usually don't
cause a performance problem.

Some ships are perfect and stay that way, others go
to hell in no time at all. Ever wonder why? We have
a 27 here in Northern California that is absolutely
perfect and it shows. It's owner just won the 18 meter
nats with it.

JJ's theory--------------Oh, lets hear yours first.
:) JJ




Hi Andy,

Apparently I misunderstood what I was told regarding the
spots(dimples) on the wing surface. During the layup of the foam core
onto the outer fabric a roller with spike like protrusions is rolled
against the foam, penetrating it. Follwing the placement of the inner
skins the assembly is vacuum bagged. I am told this is done to help
eliminate excess air. The resuting pressure forces the excess resin
into these depressions in the foam producing little spikes of hardened
resin upon curing. Apparently these spike like discontinuities cause
a non uniform deflection locally about the spikes when the wing flexes
which causes the skin to refect light differently. I am also told
that in time they could produce a slight "pimple" or dimple. At least
in my case I have not seen anything other than a reflective difference
on the surface.

You might give Ed Byars a call for a inexpensive surface gage
employing a dial indicator that he was selling a year or so ago.

I guess I now know more than I really needed to know about this.

Lorry