Most paints are too thick to spray directly
from the bottle and must be thinned prior to use. All paints are different
and will have unique spray characteristics. Experiment until the paint is
the proper consistency and dries almost on contact when sprayed. A rule of
thumb is to start with 3 parts paint to 1 part thinner (you can always add
more thinner), you want it to be the same consistency as skim milk. Check
with the manufacturer for their recommendations and proper thinner as a
Some paints (lacquer based) dry very quickly.
To prevent clogging, avoid stopping once you have started the spray
process. Always keep and extra jar of clean thinner handy to rinse out the
paint that may dry in the brush (especially if you are using lacquer).
Some of the new acrylics are capable of being
sprayed directly from the bottle without any thinning, however, most will
require the addition of water (or denatured alcohol) to allow the smooth
flow through the brush. There is no absolute rule as what ratio of paint
to solvent, you must adjust it to the current working conditions.
Moisture, atmospheric conditions, "phases
of the moon" etc. will affect the performance of the paint and brush
set up. Be flexible, change to match the conditions. It is an inexact
process so you must learn to shoot from the hip to get the results you
need. Keep experimenting until you are able to get a smooth flow and even
coverage which dries almost on contact.
TIP: A general rule is that a siphon feed brush will require
more dilution or pressure to work than a gravity feed brush.
When painting the most important thing to
remember is keep the brush clean. Let me repeat this -- keep it CLEAN!!!!
A build-up of paint even a slight one will cause spattering and uneven
coating. It will also provide those around the air brush user with a
variety of new four letter words to add to their vocabulary.
To produce a good quality coating requires a
clean airbrush. Always clean immediately after every use by rinsing with
clean solvent. Thoroughly clean and disassemble before storing your brush.
1. Attach bottle with clean
2. Open paint flow to
full and spray several times onto a newspaper, paper towel or rag.
3. Stop the fluid with
a soft cloth and force the air and solvent back through the cap and tip.
4. For thorough
cleaning disassemble tip and clean with solvent and soft cloth. If using
quick drying paints it is
advisable to soak the tip and needle for several minutes in solvent.
5. Reassemble and store
in a closed container to prevent the accumulation of dust.
I recommend thoroughly cleaning with
solvent after each colour. If you work from light colours to dark colours in
is easier as you can do a quick rinse on the brush and put in another
colour. At the end of the session disassemble the brush and soak it in
solvent. Care should be taken with rubber parts if you are using lacquer
thinner, prolonged exposure can cause them to swell and no longer fit into
your brush . It can also melt some parts. This is from personal experience
when I soaked the rubber O-ring from a Badger in thinner all night and
then couldn’t get it back into the barrel of the brush.
CHOOSING AN AIR BRUSH
Before choosing an air brush, consider the factors unique to
your particular situation.
What type of work will the air brush be used for?
What type of materials will be sprayed through the air brush?
What is the scale of the project?
What is your level of experience?
Starting with an inexpensive external mix
gravity feed is fine. It will allow you to learn the basic of airbrush use
and the proper maintenance of a very simple tool. I still use my old brush
for laying down base colours and anytime I need to apply large amounts of
colour. For details and weathering you will need an internal mix brush.
Either siphon feed or gravity feed is fine, the determining factor is the
volume of paint you will be working with. For small quantities or frequent
colour changes a gravity feed with a paint well is best.
Don’t skimp on the second brush you buy, get
the best you can afford. A high quality brush will work better and give
better results than a cheap tool. If you have to, check with the Chief
Financial Officer of the household to see if funding is available for this
unit. It is worth the extra money.
The airbrush is held in the same manner as you would hold a
pen, with the index finger held comfortably over the trigger.
1. Attach hose to air supply, turn on
compressor and allow to blow at full pressure for approximately 30 seconds
to clear the line of dirt and moisture. Turn off pump.
2. Attach the other end of tubing to airbrush.
3. Attach colour cup and add paint or attach
bottle filled 2/3 full or fill paint cup on top of brush.
4. Test your spray on old newspaper or other
scrap material -- adjust as needed by turning spray tip.
5. Always test the material you are spraying to
assure compatibility of paint and surface materials. Certain paints can
melt plastic pieces that are being sprayed.
6. Press down on trigger to paint.
7. When finished, clean airbrush as directed.
-- indicates that air and paint mix inside the air brush. Air and
paint come together inside the head assembly to produce a
thoroughly atomized fine dot spray pattern.
-- indicates that air and paint mix outside the air brush. Air and paint
come together outside the head, or fluid assembly. External mix air
brushes produce a larger dot spray pattern than internal mix air brushes.
-- refers to air brushes on which the trigger controls both air and colour
(down for air, back for colour). This simple manoeuvre allows the artist to
change the width of the line, the range of value and the opacity of paint
without stopping their hand motion.
-- refers to air brushes on which the trigger
controls only the air flow. When the trigger is depressed, a pre-set
amount of fluid is sprayed. The amount of fluid is regulated by turning
the needle adjustment screw at the back of the handle, or in case of an
external mix air brush by turning the fluid cap on the paint tip at the
front of the air brush.
-- refers to air brushes with top-mounted colour cups in which gravity
draws paint into the air brush. Less air pressure is required enabling
slower hand movement which creates excellent control for fine detail
BOTTOM or SIPHON FEED
-- refers to air brushes on which paint enters through a siphon tube or
colour cup attached to the bottom of the air brush. Removable jars or
various size colour cups can be connected to and utilized with bottom feed
air brushes. This configuration is generally more versatile and enables
the user to change colours quickly.
-- refers to air brushes on which a small colour cup fits into the
side of the air brush. The side feed colour cup rotates enabling the user
to work on either a horizontal or vertical surface. The side feed
configuration also permits the user to achieve fine detail without the
possible sight obstruction of a top mounted colour cup.
Weathering Tricks for novice modellers
Marcelo Scaminaci Russo
had chance to see military aircraft, know that there is only one time when
they look "brand new", when they come out from the assembly
line. The passage of time and the use, deteriorate the external painting
giving the airplane an aging aspect, remember that many of them fly at
supersonic speed and/or are exposed to extreme environmental conditions.
If you are building your first model, you will surely be doing it out the
box, but you can achieve incredible results, and give them a
characteristic aspect of "wear", with very few materials and a
couple of simple techniques.
process the seasoned modeller uses to give this look to the model is called
weathering. Many times it is represented on the model by the soot of the
exhaust, oil stains, chipped painting, etc., all that can really give the
model an amazing authenticity.
apply weathering techniques to a model we have to use the same logic used
by mother nature. For instance, we shouldn't put smoke stains (from the
exhaust) and then apply a gloss decal over the blackened surface. Usually,
airplanes are well preserved, they don't show dents, but smoke stains
start appearing around the exhaust exits, as well as oil drops, on some
surfaces. Many times chipped paint can be seen on the wings leading edges
and stabilizers, and on those places where the crew or mechanics walk.
Anyway, we have to keep in mind that all airplanes with a good maintenance
will show minimum amount of wear.
basic ways to show exhaust stains
The first way is with the use of an airbrush, this requires practice to
achieve the desired effect, but it's always advisable because the results
are excellent. We begin mixing three parts flat dark grey an one part flat
brown (3:1 ratio). We will apply this colour with the airbrush adjusting
needle very closed, spraying from a distance of 2 cm approximately, moving
from the exhaust exits to the back, trying to follow the exhaust gases
path. It is convenient to practice this on an old model or on a piece of
gloss paper, before working on our model. Then we will apply flat black in
the same way over the first colour.
don't get carried away with the black colour, because we want the
dark grey visible.
method is using watercolours, crayons or chalks on the black to grey range.
We begin grinding this material into a fine powder, then we will apply it
on the model rubbing it with an old paintbrush. On the exhaust outlet the
colour should be dark and thicker. The method for application should be the
same that the one used with the airbrush. The result of this technique is
not permanent, so it will be necessary to apply one or two coats of dull
varnish or lacquer, to prevent the stains from disappearing.
This kind of stains are usually very light so we will have to use very
little colour. (Oil really has very little colour so it only leaves light
We should colour thinner with some drops of black paint or ink in a 10/1
ratio, we allow a small drop to fall on the airplane surface area on which
we want the oil stains to appear, then we will blow the "oil"
drop along that area having in mind the direction the airplane flies, the
movement should be from front to back. It's not convenient to exceed with
this kind of weathering, so it will be enough to apply this technique on
one or two places.
Simulating paint chips is a simple technique, but like others is easily
overdone. A military airplane wouldn't have many chips; they usually
appear on the cutting edges of propeller blades, on the leading edges of
wings, on flying surfaces, and on the areas where the crew or mechanics
walk or they work. (i.e. on the wing roots). We should work
using aluminium colour to paint the chips, applying them with a fine pointed
brush with little paint, we apply the chips in small dots, the smaller the
better so, a very large chip would look unreal. Airplanes with control
surfaces covered with fabric (i.e.: ailerons), must have a different
treatment because the chips are not too visible, due to the flexible and
porous nature of the surfaces, making it difficult for the paint to
common technique, but for advanced modellers, consists on the double layer
paint. We apply a thin layer of silver or aluminium paint, it should cover
the whole model, then we use masking liquid (applied like white glue as
liquid dries off, and it is easy to be removed) we cover small areas in
those we want the chips appear (as we made with the silver paint in the
previous technique). When all is dried we usually apply the colour the
model requires and after several days, we remove the masked chips using
masking tape or the point of a well sharpened blade, the effect showed is
very real because the silver area appears under the colour, pretending to
be the exposed metal.
keep in mind
Try not to over do weathering and keep
practicing. Be patience, it takes time to discover and master
all the tricks this fascinating hobby offers.