Internal or External mix airbrush?

Bikerbuster,

probably, when you're reading external and internal mix, you're also seeing single or double action.  Action refers to control, in this case.  

An external mix, single action, allows you specific control on air.  Push the air button and paint is spraying.  You will have some control, though limited, on the volume of paint (which ultimately controls how fine a line and how much paint is applied to the area) you achieve with a single action airbrush.  These airbrushes are very useful for large areas of coverage or if you're really good at masking.  I have one that I use for clear coats, simply because I'm going for large area coverage with a wide mist.  This being said, I know a lot of people consider them a good starting point, and generally they can be found fairly cheap (mine cost $30 cdn).

An internal mix, or double action, gives you control on air and paint volume.  Push the button, air is moving, pull the trigger and push the button, paint is spraying.  Pull the trigger further, more paint, less trigger, less paint.  Here you can get a fine line, you can lay down light layers, you can do a wide mist.  I prefer a double action or internal mix because I get the best of both.  I find a double action offers me more control in fine lines, medium and wide coverage.  They are a little bit more to learn, you have to train your trigger finger, they range in price quite a lot (my cheap one cost me $120 cdn, my expensive set $410 cdn).  

At first, I used propellant cans.  At $14 a pop, you'll pay for a compressor in no time.

So, considering an air compressor, you will want a moisture trap (you should have one) and a pressure reducing valve with a gauge.  Some compressors come equipped with these, others don't.  Mine didn't.  I looked online at hobby sites, shopping for a moisture trap and a valve.  Ultimately, I went to Canadian Tire (a generic hardware store) and found a much cheaper set up than I could have online, and I accomplish the same job.  It all depends on what you wish to spend.

My compressor cost around $100 cdn, the moisture trap around $15, the valve was about $8.  Hobby stores online were much more expensive, I think a combination moisture trap and pressure reducer that I was looking at was $90 us.

After all of that, you will have to figure out which base of paints you're going to use (acrylic, enamel, lacquer), thinners, thinning ratios and air pressure.  It is a bit of a learning curve, but the results can be gorgeous.   You will achieve much more than you ever could with a paint brush.

I know this is a little long winded, but I hope there's some useful information in there that helps with your decision.

To supplement what AndrewW said, my advice would be to purchase a good quality single action airbrush to start off with. A Paasche H would be a good example but there are other brands to choose from and you can get more advice on which brands are best in that category from other members on here. Like AndrewW said the single-action AB's are typically less expensive than dual-action AB's and you only control the air flow when depressing the trigger. So, you're less likely, as a newbie to airbrushing, to be intimidated and discouraged by the more complex dual-action AB which takes  practice to become considerably comfortable with the trigger action. After some practice there is just no comparison to the excellent finish you achieve with an airbrush.

there is also an Internal Mix, Single Action airbrush that you can use for wide coverage, and for fine lines

It has been available for decades and decades, and there are always "better, newer" airbrushes coming out

It is a Badger (a few different numbers, these days),,,,,you can get it in gravity feed (cup on top), siphon feed (jar below it) or a combination, which is a cup off to one side that works as a gravity feed by fitting into the socket for the siphon feed jar, this is the way I do it, because I can swap from gravity cup to 3/4 ounce jar, to 2 ounce jar with at gentle twist and pull,,,,,,,one guy uses multiple gravity cups

you control the paint flow by turning the screw on the back of the airbrush, most people think you have to stop spraying to do this, but with practice you can learn to do it as you go,,,,,,,,,,,and you control the air by depressing the trigger straight down as if you are using any other single action airbrush

so, it does both things that an Internal Mix Dual Action does,,,,,but, you can "keep" your setting on the paint flow as you go,,,,,,,,you can't do that with a Dual Action unless you have practiced Trigger Action for years

I still keep the Badger Paint Sprayer around, just in case I run into something I want to spray and test without risking my "real Airbrush" with gumming up,,,,,,I have an old Testor's beginner thing around for that also, and for clear coats

The Badger I have had for so long is this one sites.google.com/.../badger-old-style-200

you will want to give this guy's site a read before you plunk down your money, also

sites.google.com/.../donsairbrushtips

Hope this helps, and enjoy practicing and using whatever setup you go with

Rex

oh, and here is what one idea for a home built air regulator system could look like,,,,,,,I was in a hurry, only had time for one stop, and it had to be a Lowe's,,,,so, I was forced to use all brass,,,there might be other options for pipe and fittings for the place you are at

you may want to change that water trap at the bottom to the drainable sort,, the hose would come in from one side if you do that

Rex

I second the recommendation for a Paasche Model H.  I've had mine for about 25 years and basically, they are unchanged since at least the 1930s, maybe longer.  I have painted over 40 scale models with mine, in all sorts of paint schemes, ie multi-color camo, NMF, single color jobs, etc.  And , all were done with enamel.

That said, the Model Hs have their limit and recently I bought my first double-action AB, a Sotar 20/20F.  I admit to being somewhat intimidated by it though, I suspect a lot of practice is in order for me now.  I'd say it was a good idea to get some experience with a single-action AB and the old H is hard to beat. Ymmv...

Gary

Badger double action gets my vote. Not the most sophisticated, but can be had for less than $ 100 and pretty indestructible.

Had a Paasche for a while but got tired of having to readjust it every time I took it apart to clean.

Stayaway from Aztek. It has a fatal design flaw in that the needle spring is in the paint path and gets all gummed up.

Also, propellant cans get expensive, I would imagine that they are bad for the environment, and the gas gets really cold if you let it flow for any length of time. That plays Willie with acrylic paints.

My preference is gravity feed, dual action from whatever manufacturer that makes the AB. Tarnship posted a link to Don's Airbrush Tips site but don't forget Don also wrote a book available from AMAZON ,free sometimes but a buck at the most. Worth it to read when considering an airbrush.

Bick, I also prefer gravity feed, dual action myself. I bought an Iwata Neo a few months ago and absolutely love it. My favorite part about it are the interchangeable paint cups. Actually, here lately, I've been painting small areas during a session and have left the cups off entirely just using a few drops of paint right in the top of the AB body. Works perfectly for me. And the ability to remove the paint cup makes it easier to clean the AB.

An internal mix AB atomizes paint much, much better than an external mix AB.  

So I use my Paasche H (external mix, single action) for spraying Future & Vallejo matte varnishes because (1) they don't need to be finely atomized, and (2) it's so easy to clean the Paasche H.

I use my Iwata SAR (internal mix, single action) for spraying Vallejo primers and  base coats of Tamiya acrylics.  

When sprayed by my Paasche H, Vallejo primers and Tamiya acrylics look grainy no matter how I adjust the AB and the psi.  However, when sprayed by my Iwata SAR, they look silk-smooth.  

Of course, for camo patterns, you need a good double action AB like the Iwata Eclipse, which I love.

In summary, if you have $$, buy a good internal mix, single action AB for large coverage and a good double action AB for detailing.  If you don't want to spend too much $$, buy a good double action AB.

Wow an absolute wealth of info there guys, thank you.  I must stress that I am only going for a beginners kit as I only envisage building one or two more kits, as when I return to full fitness, I will not have any time to spare for model making - but you never know.

So I think I will err towards the internal mix as they get far better feedback here..  Anyone heard of 'Spraycraft'?  I have spotted a wee starter kit for £60.00.  (SP50K)  I have also spotted some of the other ones listed here, but they are well over what I am looking to pay, for what I am looking to do.

I sound like a right tightwad don't I?

TarnShip, looking at your rig, you have a desiccant drier, I tried one of these for a while, but found the desiccant quickly got wet.  I also tried baking the desiccant to get the moisture out, very unsuccessfully.  I switched over to a filter and a drain trap, and much happier.  Though the rest of it looks very similar to what I have, a lot of brass, lol.

And the Badger is a nice brush, that's my cheap double action (and single action).

GMorrison, I have to argue with you about the Aztek, that's mostly all of what I use nowadays, and I love it.  Quick nozzle changes, very easy to control.  I've had no problems from the internal mechanism.  That being said, I always ultrasonic clean at the end of a paint session.

Bikerbuster, from what I google you're looking at a double action (unless I'm mistaken).  If you're going to use it more than twice, it will be well worth (in my opinion) buying all the kit and learning.  I know my girlfriend uses my setup to apply gloss to some of her artwork, so it's not only for modelling for me.  If you're using it once or twice, and putting it on the shelf for years, probably not a wise investment.  There's a lot to learn in using and especially in cleaning the brush after use.  For 60 pounds, I would find that a little pricey to use twice and stick on a shelf.  That's me.

If it were me, I would probably just settle with using rattle cans if I could find the color I'm needing in that respect. Building just one or two more models, for me, wouldn't justify buying even the cheapest airbrush set-up. Like AndrewW said, there is a lot to learn when using an AB not just with applying paint but also in maintaining it. And it takes some time to learn all that enough to get satisfactory results even for those of us who build models all our lives. Just my opinion.

Chrisk-k

Of course, for camo patterns, you need a good double action AB like the Iwata Eclipse, which I love.

While a double-action AB might make the job easier, I have to argue this assertion.  One doesn't have to have a double-action AB to paint camo patterns.  There are many examples of quite stunning paint jobs done with a single-action Paasche H, for example.  A good single-action AB will require more patience, finesse and skill but they will do the job if the painter is up to the challenge.  Again, as so often, it is the Indian, and not the arrow.

Bikerbuster

Wow an absolute wealth of info there guys, thank you.  I must stress that I am only going for a beginners kit as I only envisage building one or two more kits, as when I return to full fitness, I will not have any time to spare for model making - but you never know.

So I think I will err towards the internal mix as they get far better feedback here..  Anyone heard of 'Spraycraft'?  I have spotted a wee starter kit for £60.00.  (SP50K)  I have also spotted some of the other ones listed here, but they are well over what I am looking to pay, for what I am looking to do.

I sound like a right tightwad don't I?

If you're looking for inexpensive but serviceable, at least for a short time, have a look at THIS ONE from, HobbyKing's UK warehouse. Generic rather than brand name but likely similar manufacturer to the SP50K. Might fit you wants/needs!

Hmm.. food for thought there, I can't go to the rattle-can option as I am mobility impaired and I don't have a suitable place indoors to spray.

I like that site Bick, cheers.

Texgunner

Chrisk-k

Of course, for camo patterns, you need a good double action AB like the Iwata Eclipse, which I love.

While a double-action AB might make the job easier, I have to argue this assertion.  One doesn't have to have a double-action AB to paint camo patterns.  There are many examples of quite stunning paint jobs done with a single-action Paasche H, for example.  A good single-action AB will require more patience, finesse and skill but they will do the job if the painter is up to the challenge.  Again, as so often, it is the Indian, and not the arrow.

 

Of course, some modelers do stunning paint jobs with only paintbrushes.  But that's an exception rather than a rule. We make recommendations based on the rule of thumb. Most modelers would agree that a double action AB is generally better than a single action AB.

Chrisk-k

Texgunner

Chrisk-k

Of course, for camo patterns, you need a good double action AB like the Iwata Eclipse, which I love.

While a double-action AB might make the job easier, I have to argue this assertion.  One doesn't have to have a double-action AB to paint camo patterns.  There are many examples of quite stunning paint jobs done with a single-action Paasche H, for example.  A good single-action AB will require more patience, finesse and skill but they will do the job if the painter is up to the challenge.  Again, as so often, it is the Indian, and not the arrow.

 

Of course, some modelers do stunning paint jobs with only paintbrushes.  But that's an exception rather than a rule. We make recommendations based on the rule of thumb. Most modelers would agree that a double action AB is generally better than a single action AB.

That is true.  I did say that double-action ABs were better (well, I said they would probably make the job easier.  Is that "better"?  I think so).  But, they are not needed for a good job.  That was my assertion friend.

Well, I love my Paasche H.  Although my Iwatas are easy to clean, it's infinitely easier to clean my H.  I recently started to use a paint cup rather than a jar with my H.  That makes it even easier to clean, and I have no problem applying a smooth coat with 12-15 psi, which I wasn't able to do with a jar.    

Yeah, the old H is a workhorse for sure.  I seldom use a jar with it unless I have a lot to paint.  The cup makes clean-up much quicker, tis true.  But, the Model H has its limits, and so do I.  I am hoping that my new Sotar makes some jobs much easier to pull off.  I still haven't even hooked it up to the CO2 yet.  Hopefully I can get my feet wet soon.

Gary