 |
Categories |
 |
|
 |
Manufacturers |
|
|
|
Quick Find |
|
|
|
Information |
|
|
|
Resources |
|
|
|
| Airbrushing by Nigel Bunce |
|
|
First of all lets clear up one thing!! An Airbrush will not improve your models, infact it will make them look worse! Only once you have got the basics right can an airbrush help you to improve! That being said an Airbrush can make a model come to life. It can convey a sense of depth detail and finesse that no brush can compete with!
So lets examine what an airbrush is. As stated its not the be all and end all! Its a tool to help you acheive results that can be incredibly realistic or it can highlight every flaw on your model. An airbrush is simple its a brush that uses air to put paint on a surface !!!!! Im afraid though its not that straightforward.
A popular misconception is that an airbrush is an airbrush is an airbrush!! This is not so. Airbrushes come in two types "single action" and "double action" Cheaper alternatives are actually spray guns or atomisers! i will try to explain the difference.
An Atomiser or spraygun works by blowing air across a opening creating a vacume that lifts the paint up into the airflow producing a spray. See badger 350 paasche vlr humbrol and so on. Humbrol revell also sell a rebadged badger 200 which are single action airbrushes
Single action Airbrushes use a needle that is operated seperately from the trigger Ie a knurled screw that is at the back of the airbrush this arrangement allows the needle position to be determined by turning it in or out " in for a finer spray out for a broader coverage" Whilst the trigger controls the airflow. Whilst superb results can be obtained from this type of brush , it does not give you the finnesse and control that a double action can.
Double action ie devilbiss sprite, iawata , aztec, badger 150 etc, paasche vjr. Give you total control of both airflow and paint flow from the trigger. Pull the trigger back increases the paint flow ! Push the trigger down increases the airflow! This then gives you unlimited control of the pattern you want to use from 1/64 fine line to about 1/4 inch broad pattern.
I at this time own a Iawata A badger 200. A devilbiss 63, A paasche vjr. All have their pros and cons but despite the Iawata being twice the price of the Paasche this is my choice of use when it comes to fine detail work. What im trying to say is that an airbrush is very much an extension of you they are what you make of them and practice practice practice is the order of the day.
Single or double ??? A good double action should have a adjuster nut , wheel or screw that can be used to make the brush perform as a single action design the adjuster will push the trigger back to the desired point and all you will have to control would be the airflow!
The main drawback on some single actions is that they come with a jar receptacle rather than a paint cup. This gets in the way when you want to do fine freehand work.
as regards mediums i always use enamels not because they are better its because thats what i understand best they are what im happy using and i know the characteristics of flow dry time and coverage!
The most important thing is airflow or a compressor!!!! Please please please dont skimp on this a good silent type i.e fridge type of unit will give you many years of service and will pay for itself many times over The most important aspect of it is that unlike the diaphram kind you wont get the domestic authorities complaining about the racket! Seriously though a cheap compressor will be a mistake if it hasnt got a resevior for the air the supply will pulse!! resulting in uneven lines (almost a dot every couple of mills) A moisture trap is also essential as compressed air is hot and this holds moisture which will spatter on your paint finish causing you much annoyance and expletives. A good moisture trap will also incorporate a pressure regulator which helps no end in being able to spray a variety of consistencies and finishes. Propellent bottles are way too expensive !! You will be using 2 or three per model the costs soon adds up! you can also get a co2 tank but this to me brings other inconvieniences such as refilling etc Hope this helps a bit
Well we have discovered what an airbrush is and the types you can buy, now what can it do ????
First of all the question you should ask is what medium i need to spray?
The second question is what do i want to spray? Il assume this is models lol!
What are we spraying Acrylics,Enamels,ink Or cellulose! now that is a different kettle of fish!
What we need to look at first of all is paint thinning. For enamels acrylics the paint needs to be the consistency of milk this will allow you to spray a broad range of patterns from fine line to infill. Of course you can use a thicker mix with higher airpressure and a more open nozzle or a thinner mixture with less pressure and a more closed nozzle (gets simpler eh?) The thing is as you get more experienced you alter your mixes to accomodate the finish and the piece you are painting! For instance if you use too thick a mix with too much pressure the finish wil dry too quick or even dry before it hits the surface resulting in a coarse sandy texture on the surface this is bad!!! But if your painting a afv and you want a cast texture then this is good!!!! Too thin you will get paint runs or too much pressure, too close you will get spider legs.ut then again too thin is ok if you want a wash or tint. the secret is in the air pressure and paint flow. In other words practice experiment and be prepared to start again. Do not go out and buy a brush thinking it will give you a great finish !! it wont only you can do that with practice and perciverance. In the same thought if you buy a top of the range Iwata Micron be prepared for frustration It is an expensive bit of kit capable of producing lines a hairsbreadth thick, but totally impractical for painting a large scale model. Its like buying a 000 sable and trying to paint your model with that.(great for fine detail but sod all use for anything else). Once you are happy with a mix you are ready to start spraying. Before you approach your model try it out on a bit of paper first of all so you know you have the correct pressure and paint flow. Believe it or not i have a bit of wall next to my bench where much to the wifes displeasure i tune my brush. It is covered with squiggles and signatures where i get the pressure and flow right before i approach the model.(this is not a general recomendation though as it does cause extreme discomfort on occasions) Another important bit of advice is if you are about to spray your model, your brush is 2" from the surface , you press the trigger and pull slowly back to the point you set, and shock horror no paint flow!!!! DO NOT repeat DO NOT keep pulling the trigger back as if your lucky nothing will happen, if your not a huge wash of paint will erupt and ruin your day.
If the paint doesnt flow its for three reasons
1 The paint is too thick
2 The air pressure is too low
3 Your nozzle is blocked because of paint lumps or foreign bodies in the mix.
The only answer is to empty and clean out before restarting. Though you can minimise this by filtering your paint through the mesh on a pair of old tights. but make sure the mrs is not around before you liberate them.
Getting on to cellulose. this needs to be a really wet mix ie thinned really well as it is so volatile it has a tendancy to dry before it reaches the surface giving an orange peel effect to the finish, this can be countered by spraying thinners directly onto the surface to help even it out but it is not really recomended. Much better to use very thin coats and build up the colour gradually, this should be done using a really low pressure whilst keeping the brush moving all the time, and remembering to lift the finger from the air trigger before moving the brush away from the model.
Trying to tell people all this is probably very hit and miss! you see the important thing is to get used to your brush learn its limitations, its strengths, Is it happy spraying spraying ultra thin lines or lines perhaps a couple of mill wide will it be capable of large amounts of infill? Is the paint cup big enough not to have to refill it every 20 secs. Does it feel comfortable to hold. Does it make you want to paint??? All these points are something you may like to ponder, but in the end an experienced person with a cheap brush can produce work infinately beter than an inexperienced one with an expensive one.
So Here is a guide on how easy it is to keep your brush spick and span
If your airbrush has been unused for a while you may find it has seized or become blocked! If this is the case just disasemble it and soak it in cellulose thinners, this will dissolve all kinds of dried paint, varnish, etc. Then use a pipe cleaner soaked in thinners to clean through the body this will get rid of any last spots of crud. A cotton bud is also indespensible for cleaning the recesses in your paint cup and nozzle (make sure your needle is withdrawn first though) I then find it advisable to use a bit of sewing machine oil soaked in a kitchen towel to wipe the needle before reinserting it into the body (if some of your brushes are as old as mine they will have leather or rubber packing glands this stops them cracking!) the newer ones have teflon seals that need virtually no mntainance.
So you have just used a colour and now you want to switch. There are 2 things that you can do
1 fill the paint resevior with thinner and blow it through untill it sparays clear
2 or as i do i use a product called "Spray Away" This is an Aerosol can containing solvents and 1% machine oil this quickly blasts away any paint build up around the nozzle and will clean out the paint cup in seconds, then a final squirt in the cup blow it through and your ready to continue.
A few tips for you all to save future problems:
1 Dont use old paint it seperates and it will clog up your brush as quick as cyno would.
2 Make sure your paint is adequately thinned, the consistency of milk is about right! If not use white spirit with enamels or distilled water or alcohol with acrylics (bear in mind though acrylics with some alcohol base will dry very quickly so dont stop spraying untill your finished!
This entire tutorial was written by Nigel Bunce who sadly passed away last year! He will be greatly missed and our thoughts are always with him!
|
|
|
|
|
|
| 0 items |
|
|
|
|
|
|
Site News |
|
|
|
|
|
|
|
|
|
Currencies |
|
|
|
Our Promise
