Stuttering and blockage

[Dranu]

So I am a bit of a beginner airbrusher. I have used an Iwata Eclipse for about a year now and it works great.

Recently got an Iwata HP-BH. When it actually sprays with its 0.2mm needle its is great, but I can hardly go 2 minutes without some stuttering/sputtering of paint or blockage. This can even happen using inks, not just thinned down acrylics. I have tried various things, like thorough cleaning, but nothing seems to help. Given even inks do this I doubt Im not thinning enough, and I rarely spray under 15 psi, and normally am around 25psi. Any thoughts? Perhaps I have a defective model?

 

[Jonathon]

Is there any dry paint or ink on the needle tip? Could be tip dry. Or even though you think its clean enough, there could be something inside the nozzle causing blockage and thus the sputtering. Ive had both happen.

 

[JackEb]

i doubt its a defective model, its likely a 'cleaning issue'
Yeah i know you cleaned it... we've all been there, but it usually comes good on the 5th clean

you will need to soak the nozzle in something that will work with what you have previously used, if its the acrylic then get hold of some Createx Restorer, or some Isopropyl at a pinch, just don't drop your seals in it as well, let it soak for 24 hrs.
Use a long bristled artist brush to agitate inside the nozzle to dislodge the crude. When you reassemble the brush make sure the threads are clean, use some beeswax/chapstick (miniscule amount) to help seal the threads. Dont overtighten or you risk damaging threads.
Try spraying water (as you would when airbrushing ) for 5 minutes to see if you get the stuttering. If you dont then try with the ink, if you then start to get stuttering again the it may well be tip dry - yes even with ink!
If the acrylics arent Airbrush specific then the pigment may be to large for a .2mm nozzle and cause issues - reducing acrylics doesnt reduce pigment size just pigment load
Keep us updated

 

[markjthomson]

Cleaning or an air leak are the commonest issues... now how about an intro please stranger...

 

[Mr.Micron]

The .2 will not handle the same reduction you're using with the .35 eclipse. If it starts out spraying fine then starts to stutter then you have tip dry .
reduce your paint a little bit more . The smaller the nozzle the thinner the paint and most time the lower that psi.
Why do folks think ink flow better then water , Most ink are alcohol based and alcohol drys quick.
why cause they were not designed to be air borne.

 

[DaveG]

"inks" are no magic bullet in an airbrush. Many of them are simply thin acrylic polymer blend anyway. Most are formulated to dry very fast on a surface - whether the paper it is drawn on, or a needle it is being stripped from by a steady stream of air. I have many bottles of ink I have tested through airbrushes, and don't find any of them to offer any real advantage over properly thinned AB paint. Sometimes it isn't about how thin a substance is, but rather how much surface tension it exhibits in solution, etc... but, this is a whole different topic.

If you are having trouble with an Iwata HP-BH it is far more likely that it is something within your routine that is not acceptable to the brush, rather than the other way around. You mention acrylics, but neglected to mention what brand - they are not all created equal for our use. Many brands offer a flow improver, and/or retarder, which can be added to solution to aid in spraying.

Lastly, if you would like to cheat a little, you can try a new H&S V2 .2 needle in your Iwata. It probably won't produce quite as fine detail, but is far less prone to tip dry than the stock Iwata needle. I use one when I am looking to just cruise, and may switch back to a stock needle when I get to doing the real tight stuff.

 

[Ulli]

I almost experienced the same phenomenon yesterday. I'm pretty new to airbrushing and have to learn a lot. I'm using a H&S Infinity .15 with Schmincke colors (black most of the time). Currently i'm practicing blends, I mean horrible blends. Yesterday I had some issues with paintblobs shooting out the airbrush while pushing forward the trigger to shut off the paintflow. Schmincke colors with a decent amount of distilled water, like 1:4 worked pretty well on the first sight but if it comes to details I had a lot of problems i couldn't overcome. There have been streaks everywhere and no matther what I was trying, I couldn't do blends I'm okay with. My frustration level was nearly over 9000 and i was wondering if only I had those problems.

After mixing up some Createx Classic black with 4012 in 1:8 ratio something strange happened. The blends took longer to build up, because of the high reduction ratio, but there where some black fades, which looked like a kind of a blend . To be honest, I was pretty proud of me, creating some sorts of blends wich where acceptable and showing me progressing. I know these blends are far from things that could be seen as blends but for example I want to show you the difference.

I did both trainingsheets yesterday evening, after almost 10hrs of blend practice last week.
I'm still struggling a little with straight lines, please be kind