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Advanced Modeling Products - Clearfield, Utah : "Model
Sized - Model Compatible" modeling supplies, from Sandpaper, paint strainers, tack
rags, cotton & nitrile gloves, plastic polish, clear coating. Home of
"AeroNotes"; aircraft camouflage and markings reference.
Alclad 2 - Model
Lacquers - Natural metal finish laquer for model kits
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Chemical Compatibility of Common Model
Finishing Materials
Cover Foam Wings
With Brown Paper - Ezone
Covering & Painting Techniques
Coverite Home Page
Covering Models with Tissue and Mylar
Coverings by I.
Cooper of MArcEE
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Fibreglass Cloth
Covering by Jim Ryan
Flite-Metal - Self adhesive,
malleable, .0015 inch thick aluminium scale covering for the look of the "Real
Thing".
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KENS HANGAR : VENEER
WALNUT, CHERRY, MAPLE & MAHOGANY.
Klass Kote (epoxy paint)
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Model Research Labs
25108 Marguerite #160, Mission Viejo, CA 92692 FAX (714) 248-1074
clear
0.0015 mylar that goes on like MonoKote and other neat covering products.
They sell it in 75 ft. rolls. Composite building materials also available
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Monokote
MonoKote &
LustreKote Surface Preparation & Painting
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Polyurethane (Water based) - adhere and
finish fibreglass and Koverall cloth etc.
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Scale
Rib Stitch
Scale Stits Covering -
Polyester vinyl paints and fabric covering for models and full-sized aircraft.
Solite
- How to apply this ultra lite film
Solite -
Advanced Covering Techniques
SPAD (Simple Plastic Model Design) - use of
plastics
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Two Color Covering -
rcFU
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UltracoteŽ ( =
ProFilm =OraCover) Tips & Tricks = Horizon Hobby :
USI Laminate: Use 3mm thick film
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ARTICLES OF INTEREST :
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IRON ON
COVERING TIPS
MARKING
When cutting Iron-on type covering material, try a Farber-Castell
Uni-Ball pen to mark the covering where you want your cuts.
These type
of pens will actually write on the covering and the marks will wash
off with a damp cloth.
CUTTING
Cutting Iron-on type covering material with an X-acto knife is
made much easier when you lay the covering material on a thick bed of
newspaper. The newspaper allows the X-acto blade to completely
penetrate the covering material.
You will get straight, smooth, even cuts every time.
BACKING MATERIAL REMOVAL
Use two pieces of masking tape. At a corner of the mylar, stick
a piece of masking tape on the front and back of the covering , with
about half hanging over the edge so that the pieces of tape stick
together past the edge of the covering material.
Then peel the two
pieces of tape apart. The backing peels right off.
 Pennyplane
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lightweight building & covering for indoor duration
BLIND NUTS
Use a paper punch to cut out little circles of gummed paper. Stick these pieces to
the backside of firewall blind nuts.
by doing this, you can fuel proof the tank compartment with resin without fouling the
threads of the blind nuts.
CONNECTORS
Slide a piece of 3/8" or 1/2" heat shrink over one of the pig
tails, then push the connector together. When satisfied, slide the heat shrink over the
connection and shrink it down with your heat gun. The heat shrink can be easily removed
when necessary with an Xacto knife.
The Hows and Whys of Silkspan Covering
Author: Bruce Cronkhite
INTRODUCTION
About the time control-line started to become a very popular form of modeling,
a new type of covering material, called Silkspan, became available. It was
stronger than Japanese tissue, much easier to use, and lighter and easier to
finish than silk. Control-line modelers took to it strongly, and still use it
because of its many good points.
It, and other coverings that required dope for attachment and finishing, fell
into disfavor when high-nitro fuel proof plastic iron-on films came along. But
now the worm has turned. Electric power has now made it possible for us to take
advantage of the things we liked about Silkspan in the past: light weight, ease
of finishing, ease of repair, etc; not to mention the wonderful smell of
nitrate dope in the shop. Let me try to convince you to try it, particularly on
the new breed of small scale electrics (speed 400 types) where you need to save
weight but also want to be able to finish the plane in scale colors.
Advantages of Silkspan
1- Very light weight
2- Covering stays tight
3- Easier to apply than tissue or silk. It will conform to compound curves when
applied wet.
4- Excellent as base or filler coat over balsa
5- Takes any kind of color paint
6- Costs less than film or synthetic
Disadvantages of Silkspan
1- Not as strong as plastic film.
2- Not high-nitro fuel proof
3- Not shiny-if you care
WHAT IS SILKSPAN?
Silkspan is a type of light, thin, flexible paper with a loose random weave and
long fibres. Depending on the manufacturer it has quite variable weight, and may have
little or no "grain". That is, unlike tissue, it does not tear straight in one
direction and rough in the other. You should try to find whatever grain there is
though because, like tissue, it will shrink more with the grain than across it, so always
cover with the grain spanwise.
The random long-grain weave gives silkspan something that tissue doesn't have:
wet-strength. You can use it like cloth in covering. It will not fall apart when wet.
Silkspan now comes in three weights, at least as Sig sells it: 00, which is the lightest,
and is almost as light as tissue paper; GM, which used to stand for "gas model",
is some heavier; and SGM, which is the heaviest. There used to be some called "rubber
model silkspan" which was very light and was close to what Sig calls
"00".Silkspan used to come in colors, and may still, but Sig now sells only
white.
You should look around at some of the Free Flight or Old- Timer model supply houses for
some of the colored stuff which may be imported still.
HOW DO YOU USE IT?
Silkspan can be used to cover anything that's wood, and maybe some other things too. While
its primary use is to cover open framework, it can be used as a cover for solid balsa
before painting. In fact, it is better for this than wood filler because it is lighter and
basically smoother. The controlline stunt folks ( pardon me, Precision Aerobatic flyers)
use silkspan as the first filler coat over balsa, and they are the best airplane
finishers there are, I don't care what anyone says.
You will need:
1 Some silkspan of the weight you need. I use mostly 00, and I have covered 1/2 A models
up to a full size Buzzard Bombshell powered by
a Super Cyclone with it. It is a little delicate, so maybe GM would be better for large
models. Now is a good time to talk about delicate.
You can put your finger through Silkspan, unlike Monocoat, but you have to give up
something if you want light weight and a covering that
won't sag. 2 Nitrate Dope -- not butyrate. The difference is that nitrate will
stretch taut, and will stop stretching when it dries. Butyrate never
stops shrinking so it can warp light structures weeks after you think you've finished. I
buy my dope (and thinner) by the gallon at the
aircraft supply store at the local airport. If you don't have one of those, Sig sells it,
but the price will be higher.
3 Nitrate thinner---please don't use "paint thinner" or some such. Get it at the
same place you get the dope.4 Sharp scissors, sharp knife, sand paper of assorted grades,
and dope brushes ( 1/2 inch, and 1 inch, ) 5 A heat gun, like you would use for Monocoat.
This is a luxury; you don't
need it, but it's fun to use, and quick. 6 Dope "retarder"or plasticizer. Dave
Brown sells it under the name of "Flex All". We used to use Castor oil. Some
have used TCP. Whatever it is it is just an oil that won't dry out, at least for a very
long time. It prevents the dope from becoming brittle with age, like people. That's it.
You will need whatever finishing stuff (color) you want.
APPLYING THE COVERING
Open structure, like wings and tails: First mix some some dope, a pint or so, 50/50 with
thinner. I almost never use any dope full strength, or any thinner than that. Paint the
outline of the frame to be covered with the mix, and let it dry. Cut a piece of silkspan -
grain going long ways- enough larger than the frame to be covered to grab ahold of. Some
Silkspan has a smooth side and a "rough" side, so check for it and cover
"smooth side out".Now the fun begins. Soak that piece of silkspan in water -in
the bathroom sink is fine- and wring out most of the water. Now lay that wet silspan over
the frame like a sheet on a bed. It will just lay there, unlike monocoat. Pull it out
until it is straight, again like the bedsheet. You don't have to be too carefull;it won't
tear unless you really pull hard.. Once you have the wrinkles out and the sheet is where
you want it, paint dope
around the outline of the frame. Use your fingers to rub the dope gently through the
silkspan onto the previously doped balsa. Rub the silkspan around the frame so that it is
stuck down over and around the frame. You will be surprised how easy this is. And you had
better get used to dope on your fingers. It won't hurt, is not toxic, comes off with
thinner, will wears off soon anyway, and is something we old timers considerred part of
the fun of modelling. Dope is not like CYA or epoxy. No matter what you get it on or in,
it will always come off with nitrate thinner, even after it dries. Again remember to use
only 50/50 thinned dope for everything.Now let the frame dry, and when it is, the silkspan
will also be dry, and will
have shrunk taut, with the wrinkles gone.With a knife, or better yet fine sandpaper, trim
the silkspan around the edges. Now, with dope on your fingers again, smoothe the silkspan
down all around the edges.Make up some plasticized dope by adding Flex-All, or whatever,
to some dope, in
the amount of one tablespoon per unthinned pint. Label this jug, because you don't
want to use this stuff for attaching covering. Slather this plasticized dope all over the
silkspan and the frame, and let it dry. The covering should now start to look pretty nice,
but don't touch it till it is thoroughly dry. Then sand the covering lightly with fine
sandpaper to remove the fuzz. Then apply as many more coats of plasticized dope as you
want. I use two to keep from adding more weight than necessary. You can use the heat gun
to evaporate the dope solvents and speed up the process.That's it You have a covered
surface. Do the rest of them the same way. (I remnded myself of the Briish motorcycle
repair manuals that used to say "reassemble in reverse order".)The shrinking
silkspan can cause a light structure to warp. Hold the piece down with light weights until
the dope is dry to prevent that. I use .45 Cal. lead bullets for weights, but that may not
be politically correct now, so you may use whatever you want. Once the Nitrate is dry,
you're home free.Light sanding between dope coats will improve the ultimate finish.If
after all of your care in covering you still have a wrinkle, sometimes an application of
full strength dope will stretch it out. If not, cut out the offending section and patch
it.
Covering balsa:
This is done just like an open frame except you put dope-not plasticized-over the whole
surface to be covered. Then lay on your wet silkspan and dope over the whole sheet, rub it
in, and trim it.For compound curves like cowls, use a knife or razor blade and make slices
through the silkspan in a fan pattern across the curve- not along it, before doping. Then
rub the dope along the fan slices to get the silkspan to overlap itself as it goes around
the curve. The natural ability of the silkspan to go around curves makes this
operation much easier to do than to explain.When the dope is dry, a touch with light
sandpaper removes the overlap ridges. You can't do that with film coverings.Now paint on
more coats of dope to suit your taste sanding between each. You don't need to use
plasticized dope here because there is no need to keep the covering flexible.One thing to
notice here is that you have totally filled or covered the balsa grain. You now have a
perfect surface for...Painting or color coat:Nitrate dope and silkspan will take any
finish known to man, I think. Because of its slight roughness anything will stick to it,
and you will not need many coats to cover. You can use primer or filler if you want it to
be shiny, but sand it all off to keep the weight down For color, one light coat of Krylon,
for instance, will do for most of us. Obviously, if you have found some colored silkspan,
your final finish will be the clear dope, and that stands up to weather just fine. I have
eight models currently hanging in my garage that are as much as 30 years old. Five
ignition old-timers and three electric old-timers, and the covering still looks good on
all of them.
A word about repairs:
If you do cut or puncture the silkspan covering a frame, it is easy to repair.
Cut away the torn section, out to the nearest frame member or not, whatever seems right.
The strength of the silkspan will prevent it from tearing any further.Cut a piece of new
silkspan as much larger than the hole as you need to attach it with dope. You can
apply it either wet or dry. If its small, I generally apply it dry. Dope the patch on and
let the dope dry. If you put the patch on dry, spray it with water to shrink it, and
procede to refinish it as you did originally. With the heat gun you can complete a patch
repair in 5 minutes, up to the color coats. This has gone on longer than I had intended. I
originally wanted to talk about Tissue covering, too, but that has to be some other time.
Unlike silkspan, however, there are many articles on tissue covering in the Free Flight
journals. I will answer any questions if I can. Also this article may be freely
distributed. Just credit EZONE, please.
Bruce Cronkhite minton@worldnet.att.net
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