86 M ODEL AVIATION
SINCe MY LAST few columns have focused on exotic or
historical aspects of the hobby, this month I’ll include some
“nuts-and-bolts” items.
Although some of you may be aware of all these little tricks,
some of you may not be. Most of what I will discuss are not my
ideas, but are things I have observed and borrowed from others.
In some instances, I have forgotten the source.
Fuel Lines: When bending the required curves in metal pickup
lines for fuel tanks, use a drill bit selected to fit loosely inside
the tubing, then slowly withdraw it as the curve is formed.
This avoids the inevitable kinks and flat spots one produces
when trying to bend tubing with pliers.
It is essential that the drill bit be undersized, and that you bend
slowly and withdraw the bit slightly ahead of the curve. With
practice, very nice radius bends can be created with this simple
method.
To keep the flexible fuel line on metal tubing, it is very
helpful to wrap several rows of soft copper wire (Sig SH-330
or any .016), then flow acid-core solder over it. File the
resultant “lump” smooth, to prevent tearing the tubing.
This technique is particularly helpful when the tank is going
to be inside the model, without access hatches. One of
modeling’s major annoyances is filling the fuselage with fuel
when a line has slipped off the tubing.
The buried tank is much easier to remove when it is wrapped
horizontally with a double-layered loop of strapping tape, and has
a tab/handle of excess tape protruding from the back.
When the fuel line does slip off the tubing, discard the foam
rubber that surrounds the tank; it
is nearly impossible to remove all
the oil residue.
Flying buddy George Sauer
told me he placed oil-soaked
wooden parts of his 14-year-old
Andrews Aeromaster in a kittylitter-
filled pan, and baked it in an
oven at 300° for three hours—
with good results.
George sprayed K2r™ fabric
cleaner on less-soaked areas,
allowed them to dry, then brushed
off the resultant powder.
Sealed Fuel Systems: Rather than
pump out the remaining fuel after
each flying session, close-loop
two line setups with a short
section of inner nylon control rod.
This simple step prevents fuel
from leaking in the car and in the
shop between flying days.
You shouldn’t do this if you
aren’t going to fly again soon, and
you certainly shouldn’t use it as a
long-term solution. Although the
fuel tank is made from the same
plastic as the gallon jugs you buy
fuel in, the stopper may not hold up
indefinitely when immersed in fuel.
However, there is little reason to
D.B. Mathews
F l y i n g f o r F u n
909 N. Maize Rd., Townhouse 734, Wichita KS 67212
A pragmatic loop closure for fuel systems prevents leakage between flying.
A simple technique for bending required curves in tank lines.
empty the tank at the end of each day if you fly the model
regularly.
It is almost impossible to completely drain a tank, so use the
small section of nylon rod to join the lines—even after pumping it
dry. This will prevent the dreaded accumulation of moisture
drawn into the alcohol.
Paint Stand: If you need somewhere to put parts after you
paint them, or if you need something to hold the pieces while
you paint them, try a plastic-wrapped block of polyurethane
January 2001 87
A handy paint stand made from polyurethane foam, available at craft stores.
Superior 1⁄2A control lines are made from
SpiderWire™ fishing l ine, which is
smooth, light, and inexpensive.
foam. These blocks are sold prewrapped in craft stores, and
they can be placed in baskets to hold artificial flowers, etc.
The material is soft and noncrumbly, which makes it easy to
push wire into, it has enough weight to be fairly stable, and it’s
not affected by paints we use in modeling. However, they
cannot be white or blue foam for that reason.
The cabane struts in the photo were pushed into the foam then
sprayed with Rust-Oleum™, and newsprint was used to protect the
work surface. (The shop windows were open, and a box fan was set
up to blow out a window.) Nonwire parts can be slid over short
scraps of stiff wire, and painted the same way.
This sure beats trying to hold freshly painted parts or
leaning them on something!
Speaking of box fans, try one of the inexpensive units in
your workshop with a furnace filter taped to the back, to help
collect sanding dust and other particulate matter. You’ll be
amazed at the amount of stuff that collects in the filter, rather
than your shop and in your lungs.
Micro Pushrod: Hobby Lobby is importing small, lightweight
wire in-tube Kavan pushrod units for small Radio Control
models, from 1⁄2A-size down.
The units are supplied in 36-inch lengths of 5/64-inch outside
diameter (OD) outer plastic tubes with galvanized (for easy
soldering) 1⁄32 wire running inside.
Included are four threaded couplers, which are soldered
onto the wire after it is cut to the required length, then tiny
nylon clevises are threaded onto the couplers.
The sets are very lightweight, at only 1/2-ounce each. This is
a nice, simple, durable solution to connecting microservos to
control surfaces.
A Weighty Matter: The construction or repair of a model
frequently requires a source of weight to hold the assemblies
flat while the adhesive is setting. Bags of lead shot, books, and
full cans of vegetables can be used.
I have been using discarded ballast from fluorescent light
fixtures for many years, with success. These parts have the
advantage of flat metal bottoms and concentrated mass, and
they are free!
Office and industrial buildings replace burned-out ballast on
a regular basis, providing a bottomless source of weights for
our use.
Many years ago, ballasts contained Polychlorinated
Biphenyls (PCBs), which are proven carcinogens; modern units
do not. (This makes you wonder what is buried in landfills,
doesn’t it?)
Nonmetal Control Lines: In the very early days of 1⁄2A
Control Line, most models were flown with kite string. It
didn’t work very well, because of the material’s tendency to
stretch noticeably from the pull of the model in flight.
Later, single-strand, then .008-inch-diameter stranded cable
became available. It was much better, but rather heavy relative
to the small models. Such fine wire was rather tricky to reel in
and out, and there was the ever-present danger of getting metal
lines caught in power lines.
SpiderWire™ is .010-inch 12-pound-test fishing line, available at
Wal-Mart™ and other stores, and it works very well.
It is a Teflon®-coated composite material that is smooth,
light, and easy to reel—not to mention inexpensive.
Three-views are essential and illuminating for Scale modelers,
and for those with an abiding interest in airplanes.
Before World War II, a prime source of three-views was the
Aircraft Year Book, published annually from 1919 on. In many
instances, these three-views are the only reliable data for some
of the more-obscure and forgotten prototypes that were
manufactured before 1946.
It would be difficult to collect all volumes of the Aircraft
Year Book, because of their rarity and the expense. However,
John McDonald has compiled all 939 three-views, and has
reproduced them in a soft-bound book—Aircraft Year Book 3-
view Drawings.
John’s book not only includes American civilian and
military aircraft of the period, but includes airships, autogiros,
balloons, and gliders. The drawings are presented four threeviews
per page, including the captions, dimensions, and
specifications.
Contents are indexed alphabetically by manufacturer and by
year. Therefore, it is easy to locate a specific aircraft in the 24-
page index. Also included are 17 pages of specifications as
supplied by the manufacturers.
I highly recommend Aircraft Year Book 3-view Drawings as
a Scale source for model builders, aero historians, and aviation
nostalgia fans.
For $35 (plus $4 shipping and handling), the book offers
three-views for four cents each. It’s available from aviation
book dealers or direct from John W. Mc Donald, Box 23,
Windom KS 67491. MA
