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airbrush technique
UNITEDSTATESNAVY
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Idaho, United States
Joined: July 07, 2007
KitMaker: 241 posts
AeroScale: 150 posts
Posted: Sunday, August 19, 2007 - 07:05 AM UTC
I am getting that sinking feeling that I have wasted my money...at least it was only $70.00 on ebay......your compressor reccomendation is excellent, I will plan on eventually purchasing that set up if the freight charges are not to high as I do live in the Idaho wilderness
Tomcat31
#042
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England - North East, United Kingdom
Joined: November 18, 2006
KitMaker: 2,828 posts
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Posted: Sunday, August 19, 2007 - 06:36 AM UTC
As well as the comments above from my own personal experience, out of the three compressor I've had in the past (including the Testors mini blue compressor) the Testors one was the worst in the world to use. I got more air from passing wind than it could muster and it kept pulsating. As such after using it once it was boxed back up, sold and the proceeds used to get a better compressor. The one I have now is the Ripmax Air Compressor With Tank, Moisture Trap & Pressure Regulator (RCP104) I've never had any problems with my airbrushing since (but I'm not sure if you can get it in the States) I use a Badger 200 single action airbrush and normally spray at 10-15PSI if I'm airbrushing close up and doing detail work. If' I'm just doing an overall coat of primer or paint I normally spray at 20-25PSI at a distance of about 8-10 inches.

Hope this helps
UNITEDSTATESNAVY
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Idaho, United States
Joined: July 07, 2007
KitMaker: 241 posts
AeroScale: 150 posts
Posted: Sunday, August 19, 2007 - 05:04 AM UTC
the model master acryl primer looked rather thin out of the jar, I moved in closer and achieved better results....good enough that it looks accepable, the orange peel dissappeared, put on 3 light coats.as you have suggested I will try different pressures ect . I am quite pleased with the results so far, filled in the seams with putty and removed excess with nail polish remover/Qtips, the satisfaction of a good job I attribute to this forum I spent maybe 15 hours doing research on this site before I even started..thank you, this is a great hobby, very satisfying I have other models to move on to after this trial model.29foxtrot suggested 10 15 psi for my airbrush on my previous post "compressor questions" so I am still somewhat confused about regulator pressure limit settings, my airbrush and compressor was an ebay purchase new condition but no info on airbrush settings, will experiment, testors did not reply to my email question about psi on the a220.
Merlin
Staff MemberSenior Editor
AEROSCALE
#017
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United Kingdom
Joined: June 11, 2003
KitMaker: 17,264 posts
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Posted: Saturday, August 18, 2007 - 08:04 PM UTC
Hi Dave

In addition to everything Michael's explained, 12 psi also sounds a very low pressure to use - especially if you're spraying from 18 inches (I'd work much closer at that low a pressure).

So, follow Michael's advice on thinning the paint correctly and try upping the pressure a bit to about 25 - 30 psi. Then do some tests on glossy paper or some plastic card. You need to find a balance between the paint spattering and drying before it hits the surface (paint too thick and/or low pressure and too far away) and running out in streaks across the surface (paint too thin and/or too much pressure and too close). It's a little bit trial and error, adjusting the paint consistency, air pressure and spraying distance until you find a balance you're happy with.

Stay with it - like any new tool, an airbrush takes a little time to achieve the best results with.

All the best

Rowan
goldstandard
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California, United States
Joined: March 29, 2007
KitMaker: 208 posts
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Posted: Saturday, August 18, 2007 - 05:57 PM UTC
First, if you are using an airbrush it is absolutely critical that you make sure the paint is thin enough to flow properly. You said you didn't add any thinner, which is only okay if the paint is specifically formulated to be sprayed out of an airbrush. From what you have said about trying to smooth things out, it sounds like you are getting a rough coat which would seem to indicate using paint that is too thick. I think your best bet would be to use rubbing alcohol to strip it off and start over.

Because it is so hot up there in Idaho, another possibility is that the paint is drying before hitting the surface of the model, especially if you are holding it 18 inches away from the model! Acrylics are notorious for drying very quickly, so to counteract this you may want to buy a bottle of acrylic retarder at an art supplies store. Just follow the instructions on how much to add, in my case a single drop is good for a small bottle of paint, half full. Anything more than 10 to 15 percent tends to make the paint too sticky, even when dry. Also, when spraying with an airbrush try to move in a bit closer, when I was still using my single action Testors airbrush (with canned propellant, but without a regulator!) I worked at most a foot from the surface.

When you thin acrylic paints, the cheapest option is to just use pure rubbing alcohol. You can also use window cleaners like Windex but they contain other chemicals like ammonia that may have a detrimental effect on the binders in your paint. Many people use complicated ratios to determine how much thinner to mix, but I just add thinner until the paint has the consistency of milk. I always make sure I don't thin it too much by dragging the stirring stick up along the side of the bottle, watching to see what the trail of paint it leaves looks like. If it is so runny that it quickly drains back down without leaving much color on the side of the bottle, it is probably too thin and you may want to add a little more paint. Always test out the paint on a piece of paper to two before spraying it on the model, it will spare you from having to strip the paint off later.

Should you ever come to own an air-compressor like what my dad has for his pneumatic tools, you can easily convert it for use with an airbrush. All you got to do is do that project or two that the wife has been bugging you to do, and use that as an excuse to buy a large compressor w/ tank and some air tools. Then you will be set for life...
UNITEDSTATESNAVY
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Idaho, United States
Joined: July 07, 2007
KitMaker: 241 posts
AeroScale: 150 posts
Posted: Saturday, August 18, 2007 - 11:50 AM UTC
I just applied a coat of gray primer on a 1/72 stuka, first build, first time with airbrush, single action aztec A220 airbrush,model master acryl gray primer, testors mini blue air compressor with pressure regulator/filter/moisture trap, reg set at 12psi, paint area temp about 90 degrees farenheit, primer used right out of bottle with no additives, held brush about two 18 inches away from model.Pressure dropped off rapidly due to lack of an airtank on my compressor set up so I used short bursts on the air brush. So many reasons I can think of that caused my poor results, too hot? need some type of additive mixed in paint? or just a cheap airbrush that will give me poor results no matter what I do big question is CAN I get good results with a single action airbrush? I cannot control the temp of my garage...here in Idaho the temp range is -5 to 110 degrees, cant paint in the house or my spouse willl box my ears.Any suggestions? what first? do I fix with another coat of paint, multiple thin coats is the norm so this may smooth out after how many coats, hard to get a feel for what is a thin enough coat, I know too much results in obscuring details, how many coats of primer paint are usually necessary? two hours later after many thin coats of primer it looks good! guess I need more patience, details are not obscured with paint, I suppose the final paint will be the trick.