Please dont take this as the end all beat all to this topic, this is simply my view on how its done.
Now that we have our topic lets look at the various items that are involved in an airbrushing system.
Probaby the most important part of any airbrush system is the air source.There are numerous options for an air source, CO2 in hobby cans, big bulk Co2 canniters, compressed nitrogen canisters, airbrush compressors, shop compressors, etc... this list can go on for quite a while.
The most probable air souces are, in no certain order:
- Hobby can Co2
- Bulk Co2
- Air compressor
Hobby can Co2
This is one of the easiest sources of air to come by. The hobby can Co2 can be purchased at almost all hobby shops, Hobby Lobby, Michaels and about any other store that sales supplies for modeling. The cans come in various sizes from a couple ounces to larger cans containing 20 ounces plus. The advantage to the hobby cans is its ease of use. You simply screw on a small can tap attach your hose and you are ready to spray.
One of the downsides to the cans is the tap itself. If you look at the above photo you will notice the brass fitting coming out of the tap. It is quite small. Most airbrush hoses are designed with fittings for easy attachment to a full size compressor. They come with a 1/4 inch NPT fitting. So in order to use the cans you will not only need a tap but most likely an adaptor to convert the tap fitting to a hose fitting so you can get the air to your airbrush.
Another plus and minus is the air source itself. Co2 when used properly can be a great air source. If used incorrectly it can cause major problems. This is due to how the Co2 is store. In order to use Co2 as an air source the bottle has to put it under pressure to get it to change from a gas to liquid. By storing liquid in the can they can greatly reduce the size of the can that is needed to main the same air flow as the same Co2 source that was stored in a gas form. The only downside to this is the liquid itself. When Co2 is used it expands. This expansion allows it to change from a liquid to a gas. If however the air sources is not given enough time to convert to a gas you will notice snow flakes coming out of your airbrush! Needless to say when mixed with paint this doesnt spray to well This very rarely happens due to the slow flow rate of most airbrushes, however it can be a concern.
As you continue to spray paint your air source will start to become depleted. This leads to another problem with the Co2 systems. There is nothing worse than starting a project and finding out you dont have enough Co2 to complete it and all the local stores have already closed and you are simply out of propellant. If you choose to use this type of air source you will want to keep several cans on hand to make sure you always have more than you would need to complete your work. This also leads to another downside, price! Though the cans are fairly easy to come by and do a good job at providing an air source for your brush they dont last that long and your wallet will be hit pretty quick trying to keep yourself in Co2 to complete your body. This is where the bulk cannisters come into play.
Bulk Co2 cannisters
There is one major difference between the hobby can and bulk cannisters of Co2, pressure! The hobby cans are probably stored at roughly 100-120psi while the big bulk cannisters are stored at roughly 800-1200psi! Needless to say you cant spray this directly through your airbrush! Just like the hobby cans you have to purchase a regulator to step down the output pressure to a more managible 20-50psi. You can usually source a regulator at the same location you purchase your bulk Co2 from. Most regulators will run you anywhere from $50-200 depending on how good of quality you want.
One of the biggest downsides to use bulk cannister Co2 is the cleaniness of the Co2 itself. The tanks that the Co2 is stored in becomes rusted over time and this rust gets into the air source. So if you decide to go with a bulk system make sure you not only purchase a regulator but make sure to get a filter as well. Blowing rust into your airbrush will leads to problems with the valve and clogging of the air path ways very quickly.
Another downside to the bulk Co2 systems is price. This however is a little different than the price of the hobby cans. To get a bulk cannister you will usually need to sign a lease agreement with your Co2 supplier. These can range in price but expect to put out at least $50-100 for a lease that can be anywhere from 1year to a lifetime agreement. You also need to be prepared to pay a year maintainence fee as well. These fees range from a few bucks to a quarter of the cost of the lease agreement.
Althought the price can be a little high to get setup the actual price of the air source itself is fairly cheap. I used to help run a paintball field and we had 50lb Co2 tanks for filling at the fields and they cost just a little over $25 to fill. Now this may not sound like much but a 50lbs Co2 tank will last you for quite a while!!! I have talked with several different painters that actually prefer using the Co2 cans over a compressor as they have absolutely no noise in the production of their air source and many of them have told me they can paint for close to a month on one cylinder! Granted this all depends on how much you paint and how well your air lines are sealed but that is still a pretty fair amount of painting.
One last thing I would like to bring to everyones attention that maybe considering Co2 as a air source is the potential for dangerous levels of Co2. As I am sure many of you remember from 3rd grade science Co2 is the gas we exhaul everytime we take a breathe. If you were to place a bag over your mouth and breathe into it in a short time you would find yourself gasping or breathing harder because you had depleted the oxygen in the bag and replaced it with Co2. The same can happen with your airbrush if you do not have good air flow in the area you are painting, so take this into consideration before setting up shop in a sealed closet with no air movement!!!
So now you know about Co2 what about airbrush compressors and shop compressors, glad you asked. There are two main types of compressors we will concern ourselves with.
One of the pluses to a diaphragm compressor is the lack of oil needed to lubricate moving parts. This is a big advantage because we dont have to worry about oil getting into our air and then mixing with the paint as we spray it.
One of the biggest draw backs to the diaphragm compressor is its low volume of air output. Most diaphragm compressors are usually connected directly to the airbush, from a regulator or moisture trap. These devices are the only holding area of the compressor other than its internal plumbing and possibly small tank. This leads to the compressor running more often as the air is used to spray colors and creates pulses in the air pressure as the compressor kicks off and on trying to maintain its maximum pressure.
The maximum pressure can also be an area of concern with the diaphragm compressors. There are several smaller units on the market that produce pressure as high as 120 psi but most airbrush compressors only give you a maximum output of roughly 60 psi. This is right on the boarder line of where some acrylics need to be sprayed, without reduction.
Even though these compressors run on a more often than they dont a good quality airbrush compressor is actually very quiet. You could be sitting directly in front of the compressor and still be able to hold a normal conversation with the compressor running. You can also fix some of the pulsing pressure issues of these compressors by installing a longer airbrush hose to help increase the storage of air for the compressor.
But like any compressor these units will build water over time and a good moisture trap should be installed inline with the airbrush at some point.
Piston compressors are more often found in home shops and around the garage to keep tires, balls and what nots filled with air. The piston compressor is capable of producing a higher volume of air than the diaphragm compressor but its not without its draw backs.
Due to the moving piston this compressor usually requires oil to lubricate the system and this mixes with the air it is compressing so a oil trap needs to be placed inline on this type of compressor.
You will usually have a holding tank ranging in size from a few gallons to upwards of a hundred gallons. This is a big plus when painting as it allows for a much longer time of spraying paint before the compressor kicks on. The one downside to this is the amount of moisture that can build up in the system. Any compressor will build moisture depending on the humidity in the air but compressing the air and then storing it in large bulk tanks can cause problems if the tanks are not drained on a regular basis. Over time you will cause the inside of the tank to rust and not only will the water work its way into your brush but the rust will as well. So make sure any hold tank you are considering using has a drain valve on it some where so you can drain the tank.
There are some things you can do to help reuce the cost of both the diaphragm and piston type compressors. You can purchase a regulator and moisture trap that is built in the same unit such as this one from HarborFreight.
This unit also makes it easier on you to maintain your system as you can see when you need to drain the water from your system by viewing the transparent bowl as well as being able to make quick pressure adjustments depending on the type of paint you are spraying.
Now that we have our air source out of the way what brush do we want to connect to it?
Thats a good question to ask as there are several brushes out there to choose from and several different configurations for the various manufactures. The most common types of brushes are siphon and gravity fed brushes. I am not going to go into great length on the brush discussion but I will hit a few of the high points dealing with brush selection.
I my opinion there are three major brush manufacturers and several secondary mnufacturers. Here is a quick list of my top three manufacturers.
- Iwata - if you want a serious tool nothing beats an Iwata
- Badger - A decent quality brush at a fair price. Minor tweaks in the design could put them up there with Iwata
- Paasche - One of the oldest airbrush manufacturers still making brushes.
Now lets get to the brushes themself.
The gravity fed brush is going to be the preferred brush for most Pro painters. With the paint feeding in from the top of the brush it allows gravity to pull the paint into the air stream which means you need less pressure for it to spray the paint. This leads to the ability to spray thinner paints, finner lines, work closer to the item your paint, etc... This is the main advantage to a gravity fed brush.
The siphon brush holds its paint in a container below the bottom of the brush and uses the air source blowing apast the nozzle to create a vacuum which pulls the paint up from the jar through the nozzle. This leads to a higher air pressure needing to be used to spray the same paint that a gravity fed brush would spray. The plus to a siphon brush is the paint container itself. By having the paint in its own container quick color changes can be made when several containers of paint that are filled and ready to be sprayed. You can also get various sizes of paint containers ranging in size from as small as a quarter ounce up to several ounces. This is great when you want to switch from doing mass coverage to small area coverage. The downside to using the siphon brush is its higher pressure doesnt allow for as fine of detail work as the gravity fed brush.
Now we know about air sources and brushes how about building the system itself?
I am going to take you through my painting setup and explain a little about why I set it up like I have.
Here we have a photo of my compressor. I went with a normal piston type compressor as I use it for other air tools.
I connected the compressor to three bulk tanks to hold a higher volume of air so the compressor doesnt run as often. I simply turn the compressor on and let it fill the tanks up then I proceed to paint. I installed the additional tanks because I do most of my painting at night while my wife and kids are sleeping so it is best that the compressor doesnt kick on while I am painting With the three bulk tanks I can usually paint upwards of two eighth scale bodies before the compressor will turn on.
Here is a shot of a inline filter/moisture trap that I installed before the bulk tanks and airbrush manifold. This allows me to drain any moisture from the system and keep the tanks water and oil free as well as my airbrushes. The filter is the item the yellow hose connects to. I also built a custom manifold that allowed me to select between my bulk tanks, compressor or a combination of the two to supply air to my airbrushes. Notice the two red handles. One just below the filter and one horizontal one just before the first tank.
Here is a better shot of my manifold setup.
I have two pressure regulators in this manifold to control the pressure seperately for three different brushes. This allows me to spray both acrylics and solvent based paints without having to make pressure adjustments when I want to switch between the different paints. The first regulator is actually inline with the second regulator due to it having a built in moisture trap and filter. I plan to rework the manifold in the near future so each gang of airbrushes has its own independant pressure no matter what the other regulator is set at. Currently I have the first regulator set at roughly 40 psi for acrylics and the second regulator set at 20 psi for laquers and enamels or heavily reduced acrylics.
I also installed another ball valve at the bottom of the manifold to help drain away any moisture that may get apast the first two inline filters.
Here is a quick shot of my Airbrush stand and a couple home made holders for some of the brushes I couldnt get on the stand. I also made a holder for my hair drier. I put it at the perfect height so it is almost like quick drawing when I pull it out for use
If you look closely at this picture you will notice I have five gravity fed brushes and one siphon brush.
I use the two gravity brushes on the left side of the stand for acrylic paints while the two gravity brushes on the right side of the stand are used for laquers and enamels. The gravity brush and the siphon brush on the bottom of my bench are used for acrylics as well, althought the gravity brush down there doesnt come out very often. I find I use the ones on top of the bench for most work. The only time the one at the bottom comes out is when I need to do some fine detail work with acrylics that arent thinned.
A closeup of the stand.
I hope this helps those of you that maybe looking at setting up a airbrush system to start painting. If there are any questions you may have about my setup or about something you are looking to do feel free to ask and I will do my best to answer them ASAP.