Airbrush gives a blob. Why?

S

Sean Chappell

Guest
Hi all. Sean Chappell here. I'm new to airbrushing and need a hand with an issue diagnosis. Here's the deal...

I have an Iwata Eclipse, bottom feed airbrush. When airbrushing, paint flows fine (as fine as acrylics can, tip dry not withstanding) but when I release the trigger (air still on) I get an extra blast of paint leaving the nozzle. Fine lines are constantly ruined. What gives?

When the air is on, no paint is being released. I cleaned the needle, cleaned the nozzle and the two seem to be seated properly. There is no play in my trigger. I don't get it. Any ideas?

Thanks,

Sean
 
Might be as simple as...when you release the trigger letting the needle slap forward and pushing the paint in the nozzle out the end of the brush?try easing the trigger forward and see if it helps any.
Also would you please go to the intro section on the forum and tell us a little about yourself ? things like what paint your using,at what pressure you spray the paint, where you live in this world what you paint and how long you have been painting? all help us answer your questions thanks
 
what paint are you using and where do you call home, we may be able to recommend somewhere close for supplies
 
Sounds like a possible triggering action issue as mark mentions..generally indicates a pause in the stroke at the starting or stopping point, basically start and continue the line after you trigger the ink/paint off..


Mitches vid may explain it differently or better but heres another :) I am assuming though your not meaning a physical blob of paint but more a dot on the end or start of your lines. Good luck..If it is a blob, may just be a dirty gun as also mentioned
 
I have this happen all the time especially when I am trying to paint tiny lines with extreme precision. The basic reason I have found is that I am shutting off the paint and air suddenly and at the same time stopping my hand movements. All that needs to be done is concentrate just like in that video clip on keeping the air flowing after stopping the paint while keeping the motion of your hand.


Paint on
 
I have this happen all the time especially when I am trying to paint tiny lines with extreme precision. The basic reason I have found is that I am shutting off the paint and air suddenly and at the same time stopping my hand movements. All that needs to be done is concentrate just like in that video clip on keeping the air flowing after stopping the paint while keeping the motion of your hand.


Paint on
I'd like to say that is it but I still think there's a physical fault with my airbrush. Sometimes, as I'm pulling back on the trigger (air on) I'll release the trigger back to it's resting position and, BAM, I get a dot, even though paint was never flowing. It's a bit of a mystery to me.
 
When this happens to me, I either reduce my paint a little more or I increase the air pressure. Bam....Gone
Cheers
I'll give that a try. I am mixing my own paints. Maybe they're not thin enough. Would you recommend water or reducer? I try go half and half. Thanks twood :)
 
Hello Sean
It would help a lot to know the brand name of the paint your using.
Is it designed for airbrushing or are you using paints designed for Models ?
Model paint has larger pigments in it while airbrush paint is ground finer. I always suggest using the MFG reducer being some "water Based " paint do have chemicals in them and water will just gum up the works.
 
Always use the recommended reducer, be it water, or the paint brands specific one, but as Herb said, mixing is not good.

Even though you cleaned it, it may still be a dirty nozzle. If its not seated perfectly then there will be a little extra build up that gets forced out when the needle tries to return to its usual position.

Being able to see through it, and it looking clean, doesn't mean it is, you will be amazed at what can hide in there. If you gently move the needle in and out by hand, you might be able to feel if it seems spongy or sticky, and irregular spray pattern, having to pull back farther for paint, too much paint at once, is a sign of a possible blockage.

As mentioned technique can make dots at the end of lines too. Snap off the paint, but keep the air on while continuing the movement of the stroke stops this. But knowing your brush is 100% clean will allow you to focus on technique, and eliminate the other possibilities. It may be that you have to soak the nozzle to be able to remove any stubborn paint :)
 
I'd like to say that is it but I still think there's a physical fault with my airbrush. Sometimes, as I'm pulling back on the trigger (air on) I'll release the trigger back to it's resting position and, BAM, I get a dot, even though paint was never flowing. It's a bit of a mystery to me.
Well think of it this way. Where is the paint? Inside the nozzle and surrounding the needle, so if you pull it back and then go forward friction will pull paint forward leaving a small amount of paint on the tip. That is why you start the air pointing away from you artwork. There could be a slight tip problem on the needle that is microscopic and dragging and catching paint, but if you put in a new needle and it persists it is most likely your mechanics of how you airbrush. Please don't take that as an insult. I have the same issue when I paint with my Micron C+. I have to be real conscious of how I stop and start and once I am back into my rhythm it goes away. Now my HP-B and HP-C both have a tendency of the needle not seating properly in the nozzle and when I start the air I am actually spraying a tiny amount of paint already. All I do for that is loosen the chuck nut, give the needle a 1/4 turn and reset the needle. But that's a whole separate issue.

Next time it happens pay attention to the weather you are having. A lot of times the weather messes with how paint flows. Even if you are running a dehumidifier and drying out the air static can build on the tip of the needle and cause drag which makes the paint stick. Another thing is how you clean the needle and airbrush. I noticed I had extra issues while using a home made cleaning solution that included glycerin. Since I stoped using it some of these same issues have stopped. I tested my theory one day by whipping down a needle with straight glycerin and sat and watched the needle as water molecules began to collect on the needle right out of the air. Just be smart and switch one thing at a time and see if things change. That way you will know what it is.


Paint on
 
I think your problem could be one of these:

-Dirty nozzle and or needle tip
-Dirty needle O ring and or dirty needle at the point of the O ring =needle does not return immediately after releasing the trigger
-Needle return spring adjusted improperly =too loose

Be careful what you use as a reducer, some paints cannot be reduced with water, even though they are "water based". I'd say they are more like waterborne. They can gum up your airbrush and cause problems.
 
I think your problem could be one of these:

-Dirty nozzle and or needle tip
-Dirty needle O ring and or dirty needle at the point of the O ring =needle does not return immediately after releasing the trigger
-Needle return spring adjusted improperly =too loose

Be careful what you use as a reducer, some paints cannot be reduced with water, even though they are "water based". I'd say they are more like waterborne. They can gum up your airbrush and cause problems.
I don't believe it would be the dirty o ring with a sticking needle because that would leave a tail at the end of a stroke. And even the needle spring tension would do the same. Take it from me I have had the same issue and it was not dirt anything. I tear all mine down after every session and run cleaning brushes through with cleaners and once in a while use Restorer. So I knew my brushes were spotless with brand new needles and still had the same dot at the end of a stroke. I only had it stop after changing my cleaner and being careful not to close the trigger to fast and stop moving my hand.


Paint on
 
Easiest way to tell would be if you can take a little video of what it is thats happening and post it up, will help us help you more..:)
 
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