SEN-451 August 9 2000

News and Reports 2000 - second half
SCAT Electronic News 9 August 2000 issue 451


Table of Contents
=================
Colors and Dust Devils part 0 - Thorkildesen
Dust Devils pt 1 - Ditto
Dust Devil pt 2 - Bogie
Your mother's Saran Wrap is not what it used to be - Markos
Carbon Foam - Ross
RE: Icarex Inquiry - Gregorie
Help at the US Team Selection Finals - Slobat
Likely Icarex suspects - Hines

Colors and Dust Devils part 0
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I have had the same problem with yellow and on a small model with yellow
tips the tips just disappear at high altitude. I like to use a couple of
yellow rib bays before the dihedral break and use red for the tips and then
the contrast shows up great.

I once timed a blue B gas model of Gene Terra's against a blue sky that had
no turn in it and flew straight down wind at the 84 Reno nats. That was
good for about 1.5 to 2 minutes before it was out of sight.

Thermals,

Terry Thorkildsen

[ I have Red and Green on my F1B - I know I'm in going up in good lift
whan I cannot see the green any more. I think I've got to replace it with
black with a white dot - that seems to work well! :-)]

Dust Devils pt 1
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I always thought that with a small light model launching into a dusk devil
can be a real disaster but if you launch a larger gas model about 25 or 30
secs after it goes through you can get into the lift without getting dumped
out.

I have done this on occasion and I assume this doesn't make me a relative of
a donkey.

Thermals,

Terry Thorkildsen


Dust Devil pt 2
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Your launching after the center of the dust devil blows by is the safe way to
do it. I was remembering people launching power models and HLG to center
around the small tornado with hellish results. Things are a lot safer
several hundred feet up around the center.

Bill




Your mother's Saran Wrap is not what it used to be
===================================================
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Roger,
The brand name "Saran Wrap" can no longer be found on supermaket shelves.
However, the same stuff is now called "Saran Classic." Don't confuse the
Saran "Cling-Plus" with the former. Cling-Plus is a new brand with the
Saran name; it's polyethylene plastic (replacing Handi-Wrap) while the Saran
Classic is a polyvinylchloride plastic (PVC). Several of us use the PVC
plastic with epoxy set-ups since epoxy does not stick to PVC and it also has
good thermal qualities; heating to 200 degrees F does not melt PVC but
causes it to shrink quite a bit to compress the epoxy/CF to the mold....no
need to vacuum bag small parts. Most of us also know that CA glues will
stick to PVC but not to polyethylene when it's used to protect the part
under construction from sticking to the plans.
Chuck


Carbon Foam
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The info on carbon foam sounds very interesting. I intend to follow up to see
if it is useful on small FF models-Thanks -Don Ross



RE: Icarex Inquiry
==================
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> As I have two wings ready to cover, one carbon and the other balsa, I am
> debating the feasibility of using Icarex polycarbonate fabric.
>
So far I have only one model, a carbon F1A, covered with Ikarex and haven't
flow it very much. However, I like the covering and will certainly use it in
future.

However, I'm not certain its suitable for a balsa structure. If your wood
wing relies on the covering for stiffness I'd suggest you cover it with
paper instead.

> The test panels I've done were very encouraging, in terms of ease of
> application, shrinkage, strength and rigidity. One concern is the
> porosity
> of a woven fabric, as air does move through this material, albeit very
> slowly. With the help of methanol and nitromethane, engine lubricants
> also find their way though the weave.
>
Yes: you can rub fuel through Ikarex and it will work its way through during
normal use. The folks who are using it on power models are fuel proofing
their inner panels.

Don't forget that Micafilm isn't fuel proof either though you might get
lucky with some batches.

Another option is Toray. Its the same weight as Ikarex, comes from the same
sources and doesn't have the range of colours as Ikarex, but the sample I
tested seemed to be completely fuel proof. I intend to use it on an F1J when
I get a round tuit. Maybe next year.

> Also, the ripstop pattern of this covering does not duplicate the smooth
> surfaces easily achieved with film coverings.
>
I don't think this is a disadvantage at all. The drag increase seems fairly
minimal and the surface is self turbulating. The worst I'd say is that its
probably harder to wash engine goo off it than off a moneycoat type of
finish.
>
Martin
London, UK




Help at the US Team Selection Finals
====================================
"George &/or Judi Batiuk"



Hi Roger, We are off to Prague tomorrow, I will send results as they become
available. On another subject; when I got the list of finals flyers, I
did some simple math and came up with a 20 timer shortage when F1B flies. I
asked the committee to try a different scheme this time, but they said I am
bound to the present system. I would therefore like to put out a call to
anyone available to come help us time. There is money available to pay
people, but not much, probably not even enough to cover Lost Hills
expenses. $1200 divided by the number of timers. Anyway, anyone that
could help us should contact me ASAP. I'll be back on the 20th. Thermals
GB


[George,

All the best at the Junior World Champs. On the other subject
I did that math too .. one plea I would like to put is out
is to the helpers for the sportsmen in F1A and F1C to also help in
timing F1B. I'm not sure how George can up with his numbers
but looking on the back of my envelope I see that there will be about
45 - 50 in F1B and half that number each of F1A and F1C.

The popularity of F1B is a major problem for the finals that
the team selection commitee and the current selection process does
not address properly. For example at the last
finals when flying F1B - my timer was only there at the beginning the
round about half the time and I had to go off and find either the
organizer or timer.

So if you can help out e-mail George at This email address is being protected from spambots. You need JavaScript enabled to view it. or SEM
This email address is being protected from spambots. You need JavaScript enabled to view it. ]


Likely Icarex suspects
======================
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Dave, I saw several Icarex covered planes at the Nats and they did look good.
Ed Keck and Dick Covalt were the flier/builders. Also Art and David Ellis
use it on F1As, top surface only as I observed.
Eds' looked shiny and Dick was sure he had put a clearcoat on for pore closure
and fuelproofing. Dick had not, but will in future, since oil had
seeped thru in places as you mentioned.
It seemed a good product which they are happy with.
Try to get in touch with them for the straight answers.
Lee Hines



..................
Roger Morrell