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need some expertise on airbrushing. Whenever I use my airbrush I sometimes get small or larger splotches that come out, & I rarely get a smooth finish. So I'm wondering is it

more pratice or is it the quality of the brush,a Veda?

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Richard, it definitely sounds like a dirty airbrush or possibly an uneven pressure source of air. Try completely disassembling the airbrush to thoroughly clean all internal components of all dirty and dried paint. Failing that, switch airbrush/air sources with another fellow modeler to determine the source of your problem. Good luck with your investigation.

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Pressure depends on airbrush and on what kind of paint you are shooting....try experimenting.... shoot at 15, 20, 25, 30, 35, and 40....using the same paint thinned the same way... (stir paint before each attempt) and keep distance to the surface to be painted the same... cut out as many variables as possible so you can see what the difference in pressure does.

 

I agree with Mike though....sounds like the brush is still dirty....probably along the tunnel thru which the needle slides.

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Do you a compressor with a reservoir or a water trap? It could also be atmospheric issues

 

Not with the one I'm currently using.

 

When you say clean the brush, what I essentially do is unscrew the forward nozzle clean it using thinner, then make sure I can see straight through it, next I clean the needle and make sure no paint is on it, and I continue to check to make sure no paint is blocking the piece that produces the air, the piece behind the nozzle. This is all done after I have run thinner through the brush 'til all that was coming out was thinner. Is that right correct way to do it? Because I have never "overhauled" the brush, and don't know how to do it.

Edited by burner12
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You might also check the air outlet...it's one or two small holes on the front of the airbrush body, beside where the tip seats into the body. If there is blockage there, it would cause your airflow to be spotty. Clean that area, and use a small wire or something similar to be sure tthe opening is clear. Otherwise, I'm with the others...it may be the air supply source, or moisture in the compressor tank.

 

 

At 40 psi, you may be getting blowback at the tip...paint coming out around the tip instead of going through it (a friend had this problem at 35 psi)...that would allow paint to get into the air outlet as I described.

Edited by Keith Pruitt
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I've also found that high humidity can be an issue from time to time especially during a rainy season, despite the water trap on the airbrush. My rule of thumb is to try to get a less humid day (With the La Nina -(drought) dry weather pattern-this should be easier for us here in Texas) and experiment. Use light, even coats. With time you'll do well. Best,

 

 

Mark Fiedler (aAzZ09)

 

IPMS #14333

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Agree with the others about your splotches. When you say you rarely get a smooth finish, is it pebbly? That would be from the paint drying before it gets on the model, in which case, dial the air back. I typically spray between 10 and 25 psi - lower for the up-close, fine stuff, and higher for base coats.

 

Might also check your needle and tip for bends and cracks - that will cause sputtering...

Edited by BobPauly
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Agree with the others about your splotches. When you say you rarely get a smooth finish, is it pebbly? That would be from the paint drying before it gets on the model, in which case, dial the air back. I typically spray between 10 and 25 psi - lower for the up-close, fine stuff, and higher for base coats.

 

Might also check your needle and tip for bends and cracks - that will cause sputtering...

 

No what i mean by "smooth finish" is that it comes out nice and fine, no puddles, or splotches, just right showing the detail. Didn't know about changing the pressure for different uses, thanks

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Don't rule out improperly thinned paint. If the wrong thinner is used, it could blob up. Or, if the paint is old, it may not be able to be thinned properly anymore.

 

Just one more variable added to the pile.

 

If you get a water trap, do not put it right on the compressor. It just plain won't work. First put on about 5-10 feet of air hose, then connect that to the trap, and then more hose to the air brush. I use to have a severe water droplet problem, but when I did this, it just went away and the trap started working. Simple explanation, traps are designed to trap water, but when the air comes out of the compressor it's not in water form, it's water vapor and it passes right through the trap. Further on down the line, it cools and condenses out and can be caught by the trap.

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I'm not familiar with the Versa AB but, you may have a cracked nozzle. That's the part where the needle seats. Even a very small crack in the nozzle will prevent proper atomization. Proper paint thinning is also critical. Try using the thinner supplied by the paint manufacturer and make sure your using enamel thinner with enamel paint and acrylic thinner with acrylic paint. I usually thin paint at a 50/50 ratio and almost never spray over 25psi. Usually 15/20psi. Ron's coments about a moisture trap may also help. Lastly, when you're sure the AB is clean, try spraying plain water. If you can't get a fine mist and good spray pattern you may need a complete re-build or a new AB.

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I was getting these blotches of paint with a Paasche H a/b using enamel paints. I was told to thin the paint more and turn down the pressure. After some experimentation with Testor's and Floquil, thinning 3:2 ratio and using between 20-25 psi works pretty good.

Ron W.

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I was getting these blotches of paint with a Paasche H a/b using enamel paints. I was told to thin the paint more and turn down the pressure. After some experimentation with Testor's and Floquil, thinning 3:2 ratio and using between 20-25 psi works pretty good.

Ron W.

 

Interesting, must have the paint too thick, and pressure too high.

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Richard,

I was originally thinning the paint per Testor's recommendations and using around 30-35 psi. Every time I pressed the trigger I got those splats. It also helped with the dusting.

Ron W.

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