Mylar seals for PIK20D

[culverflyer]

any first hand experiences? i am considering some for my 20

[Chuck Lohre]

I purchased a PIK 20D which had top mylars. They were in good shape so
we just put some safety tape on them. The ship did not circle very well
because you couldn't slow up without hearing the separation on the
airfoil and feel the stall mush. I decided to put mylars on the lower
surface. Internal seals seemed impossible because the ailerons and flaps
have to move side ways to assemble. After Eastern Sailplane installed
the lower seals the ship performed much better. I had also installed new
push rod seals for the flaps and ailerons both at the root and the
outboard exit.. With its new configuration I could circle much slower,
about 43-45 kts with 8 degrees of flaps. Previously the ship needed to
fly at 47-50 kts. I finally settled with 6 degrees as the best setting
for average thermals here in Ohio. My theory was that the lack of lower
seals was allowing higher pressure air to go right up through the wing
escape through by pushing up the top seals and spoil the laminar flow
aft of the flaps & airelons. With the lower seals being pressurized an
pushed into the gap they created a much better natural seal. My
thermalling was much improved and I was able to stay in a gaggle with
much later glass without having to fly faster and have a larger diameter
circle. Weaker thermals were usable. I finally got the performance
expected. I can't remember if we used the 25 mm or the 30 mm mylar but
we chose the smallest tape possible. There is considerable stress on the
tape when the flaps are lowered for landing but good preparation and
safety tape will do the job. I recommend you have a professional install
them. We used a "Monocote" heat shrink model aircraft application iron
to improve the adhesive seal where delamination was taking place in a
few stops. It is a small iron with a Teflon coating. I glad you asked a
question I could help with. Please e-mail me directly or call if you
want to chat. REMOVE "NOSPAM" from my address to respond.

culverflyer wrote:
>
> any first hand experiences? i am considering some for my 20

--
Best Regards,
Chuck Lohre, Lohre & Associates, Inc., Marketing Engineering
2330 Victory Parkway, Suite 701, Cincinnati, OH 45206
Toll Free: 877-608-1736, 513-961-1174, Cell: 513-260-9025
Fax: 513-961-1192, E-mail:
Marketing Handbook: http://www.lohre.com/extra/index.html

[Janos Bauer]

Chuck Lohre wrote:

> Internal seals seemed impossible because the ailerons and flaps
> have to move side ways to assemble.

Hmm, it should be possible somehow since our pik was factory installed
with it.

/Janos

[Chris]

"S" seals are possible and I've replaced them in a PIK, just make the seals
long enough to allow side movement when refitting to hinge pins, probably do
not require "S" seals if Mylar's are fitted top and bottom

Chris Runeckles
Universal Plastics P/L

"Janos Bauer" > wrote in message
...
> Chuck Lohre wrote:
>
> > Internal seals seemed impossible because the ailerons and flaps
> > have to move side ways to assemble.
>
> Hmm, it should be possible somehow since our pik was factory installed
> with it.
>
> /Janos

[culverflyer]

With the S seals would there be an advantage to have the external Mylar's?
"Chris" > wrote in message
. au...
> "S" seals are possible and I've replaced them in a PIK, just make the
seals
> long enough to allow side movement when refitting to hinge pins, probably
do
> not require "S" seals if Mylar's are fitted top and bottom
>
> Chris Runeckles
> Universal Plastics P/L
>
> "Janos Bauer" > wrote in message
> ...
> > Chuck Lohre wrote:
> >
> > > Internal seals seemed impossible because the ailerons and flaps
> > > have to move side ways to assemble.
> >
> > Hmm, it should be possible somehow since our pik was factory installed
> > with it.
> >
> > /Janos
>
>

[F.L. Whiteley]

Of course, only empirical testing will provide an answer WRT the PIK20D,
however, positive results were achieved in the Dick Johnson Ventus 2 flight
test. See part 2
http://www.ssa.org/Johnson/80-1996-06.pdf

Good sealing generally yields good results.

Frank Whiteley

"culverflyer" > wrote in message
...
> With the S seals would there be an advantage to have the external Mylar's?
> "Chris" > wrote in message
> . au...
> > "S" seals are possible and I've replaced them in a PIK, just make the
> seals
> > long enough to allow side movement when refitting to hinge pins,
probably
> do
> > not require "S" seals if Mylar's are fitted top and bottom
> >
> > Chris Runeckles
> > Universal Plastics P/L
> >
> > "Janos Bauer" > wrote in message
> > ...
> > > Chuck Lohre wrote:
> > >
> > > > Internal seals seemed impossible because the ailerons and flaps
> > > > have to move side ways to assemble.
> > >
> > > Hmm, it should be possible somehow since our pik was factory
installed
> > > with it.
> > >
> > > /Janos
> >
> >
>
>