From the newsletter of the St. Paul Model Radio Controllers, Inc., Coon
by Ellie Pflager
I was asked to research airplane
covering materials and their weight ratio. I have
learned a great deal in doing this article. I guess
you could say that I have had several “ah-ha”
moments and now a lot of things that were discussed
during show-and-tells make a lot more sense to me.
For my research I looked at both manufacturers’ Web
sites as well as many forum group sites and tried to
find multiple “agreeable opinions.” Bob LaBrash was
a great help when it came to the product weights; he
gave me a great head start. Hope you find this
[Tech. Editor’s Note: There is some
misinformation here. There are several types of
“tissue,” but the lightest and best is known as
Japanese tissue. The “grain” has to be determined,
usually by tearing, it is not that noticeable. The
grain is then laid down span-wise on a wing, and
this instruction is very important. Good tissuing is
This is not Kleenex, but more like gift-wrap tissue.
It really is paper that comes in different weights.
Tissue works best on the lightest models; usually
balsa models designed for Free Flight (not RC). It
has a noticeable grain to it, and this grain should
be applied in the direction needing most strength.
It is traditionally applied to the wood frame with
dope, although thinned glue works fine. Once the
tissue is applied to the structure, it is shrunk
tight with a light mist of water, then sealed with
dope or Krylon spray enamel.
This covering is actually woven silk fabric that is
applied with dope. From what I could tell this
covering is not used very often these days. I
couldn’t find any other information on this type.
This is like tissue but contains other fibers, and
is generally stronger but heavier. It can be applied
in the same manner as tissue. It is a good covering
for foam. The weight per square yard of this
material is 6.17 ounces.
Fabric covering can produce a very realistic finish
and can be painted or purchased painted. Some are
manufactured from real woven cloth and feature a
simulated, hand-rubbed lacquer finish like full-size
airplane finishes. It goes on like a film; roll out
and apply, then iron on at low heat to properly
activate the adhesive. Because of the low-heat iron
it can be used on sheeted foam. The weight per
square yard of this material ranges from 2.9 to 3.3
ounces based on brand.
This woven material is great on solid structures,
but not good over open areas. It can be used to seal
balsa wood or foam and comes in a great variety of
weights, the lightest (.5 ounces per square yard)
being very light but flexible. This is a great
substitute for silkspan when covering foam. It may
be applied with epoxy (wood) or water-based
polycrylic (foam). It adds great surface strength
for very little weight. It can be applied in (or
over) a form to produce a “shell” for a nose cone or
Plastic Coverings are also known as polyester films,
or heat-shrink coverings. These are all applied to
the wood frame with heat that activates an adhesive
layer on the underside of the film. Once the film is
attached to the finished airplane kit frame, it is
then shrunk tight with heat. Film types of covering
produce the lightest model. The weight per square
yard of this material ranges from 1.685 ounces to
2.700 ounces based on brand and color. Below are
some brand comparisons that I did based on forum
1. Ultracote by Hangar 9: polyester type with a
2. MonoKote by Top Flite: supposedly preferred due
to a high-gloss, smooth finish and is long lasting
3. 21st Century Film by Coverite: handles extreme
temperature and humidity changes.
4. Litespan by Solarfilm Company: much lighter than
MonoKote or Ultracote and has no adhesive on the
underside, said not to shrink quite as drum tight as
the other films. A 20 x 36-inch sheet weighs 31.8
5. Solite (Litefilm) by Nelson: super-light film but
has adhesive on the underside, some of the “opaque”
colors are somewhat translucent.
Painting is another option for finishing an
airplane. Wood or foam structures must be sealed
before painting to help produce a smooth paint
surface. Surfaces that are sealed should not need as
much paint and that will help keep the weight down.
A primer coat is often applied after sealing. Its
function is to create a surface that will bond well
(chemically) with the paint layer.
I found there are several types of paint, each with
their own benefits. Some examples are: dope, enamel,
acrylic, and latex. Dope is a cellulose lacquer.
Enamel gives a great finish but is tricky to clean
up and dries slowly. Water-based acrylic dries
quickly, easy to cleanup, and supposedly does not
attack foam or wood. Acrylics tend to dry flat, so
glass finishes need a separate clear coat. If your
model plane kit (or heli) will use glow or gasoline
fuel, the paint finish will need to be fuel proof.
Many common paints are not fuel proof so make sure
your topcoat is fuel proof, possibly a clear.
In my research I found the following Web site
tutorials that seemed good to me. Thought I would
pass them on.
Tips for covering RC airplanes with heat shrink
Tips for covering RC airplanes with fiberglass: