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Wednesday, February 3, 2016

More airbrushing questions


My airbrush saga just gets curiouser and curiouser. Monday night I decided my left arm was doing well enough that I could tolerate a short round of airbrushing. The arm did fine, but I'm not sure my blood pressure was within proper limits the whole time.

Same old problems; the brush would not push paint through in sufficient quantities. Pure thinner seemed to go through well enough, but add some paint and things just stopped. If I thinned it to the point that it would move through the airbrush, then it was too thin to add any tint whatsoever to the target model.

Out of desperation, I found a workaround, but it is the sort that just emphasizes the problems you are having. If I loosen the needle chucking nut and manually pull the needle back a tad, paint comes out in a strong stream. It works well enough when you are painting large areas, but as you can imagine, you have to be extremely careful not to apply the paint too thickly or allow it to pool or run. And this technique wouldn't work if the task at hand was fine Luftwaffe mottling. But it does seem to get the paint on to the model more efficiently. This paragraph probably contains the root cause of my issues, but I am just not enough of an airbrush engineer to know what is going on. I'm like that with cars too: if it runs, great. If it's broke, find someone to fix it.

But I did get a definite color coat of Middle Stone on one of the Eurofighters and the desert Hurricane. And I got sufficient matte sealer coats on three completions, which will be debuting here over the next few days.


Next up in terms of paint is the surface coat of the Middle Stone. My definition of that is a relatively well thinned coat meant to restore the surface level after a bit of fine-grade sandpaper buffing. It's an extra step that can be eliminated if you get a nice smooth gloss first coat, but that doesn't seem to be where I'm at right now. Plus I have lower surfaces on a whif Messerschmitt P-1106 and uppers on a Fi-103X that need the same sort of treatment. 


8 comments:

  1. ..without looking I guess you use acrylics. I lost a number of airbrushes to the insidious, invisible and irreversible built-up that occurs with long-term acrylic use. And you use a brush you can't really disassemble either IIRC. Having said that the best move I made recently was a new compressor with pressure regulator, moisture trap, tank, the works. A revelation!

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  2. Actually, no. I am a thorough enamel/lacquer sort of guy. Generally Xtracolour (which is why I've been so bummed about their unavailability due to postal restrictions) with occasional Model Master or Humbrol if I need a certain shade. You can disassemble an Iwata Eclipse HP-CS but you can't really access the deep internal parts where air pressure meets paint. I have already picked out a new compressor and accessories, but at my current income level that isn't possible, so I'm stuck soldiering on with the one I have. Definitely no acrylic fan: I admit that I haven't used the current generation, but I had problems with the paint adhering to surface and inability to sand/buff it, when I have used them experimentally in the past.

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  3. Hmm, I regularly switch back and forth between acrylics and enamels...although I prefer acrylics. The basic physics are air pressure passing through the nozzle cause a reduced pressure that pulls fluid from the reservoir when the needle pulls back, opening the orifice. Lots of individual things can go wrong for the system to fail.

    How certain are you that the orifice is clean? I find occasionally a very tiny bit of pipe cleaner gets lodged inside. Blocks good flow, but seems fine when very thinned (useless) paint is tried. It takes cleaning with a plastic brush (specific to airbrushes).

    Just a thought,
    Tim

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  4. Have you considered sending your AB to iwata for a servicing/cleaning? You never know you may have a defective doo-hikky from the factory or something???

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  5. Tim: I can't claim that the orifice is clean (good grief, I hope that phrase doesn't come up in a google search). In fact, I think that is the ultimate problem - inability to clean the airbrush properly. That and possible damage to the needle. That is why I am looking closely at a sonic cleaner and some new airbrush parts. I don't have a specific wire brush to get down inside, which is also a disadvantage.

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    Replies
    1. Take a look at these brushes: http://www.amazon.com/gp/product/B001N3IX3Y?psc=1&redirect=true&ref_=ox_sc_act_title_2&smid=A23ADOZFIJNPFB

      If the needle is the culprit, you should be able to sight along its length and confirm it's straight or has a kink in the end. I had one bend slightly at the very tip and could feel it when I ran it across the back of my hand.

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    2. Tim: Those brushes look very worthwhile. I've put them on my list and will pick some up the next time I order from Amazon. And I believe the needle does bend a bit to the south at the tip, so have resigned myself to acquiring a new needle.

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  6. SR: I actually have done that once a few years back, and was very satisfied with the work they did. I just don't have a spare $75 at present.

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