Nozzle size - what’s it all about?

[Guest]

Being an aspiring airbrusher, and having bought one of the cheapo Chinese jobbies with three different needle sizes, I’d like to know what the purpose of each is please? I’m guessing it may not be an easy, or rather straightforward, question to answer.
As always, any help appreciated.
Max

[dave]

Simple answer, smaller the nozzle the finer the spray pattern that can be achieved

[Mr Bowcat]

Exactly as Dave said. Use the bigger nozzle/needle when you want to put down paint over a large area (so the primer and top coat over the entire model) and the smaller ones for more delicate work (spraying in thin lines on panel lines, streaking, mottling, etc).

[Guest]

Thanks for those replies boys! So the larger 0.5 I think, lays down a fine enough coat for primer then? Would using the 0.3 tend to clog, or would it just not spray it?

[Guest]

I use a 3.5 needle and it’s fine for everything.

[Guest]

My cheapie has 0.2, 0.3 and 0.5. So 0.2 for fine line work, 0.3 general purpose, and 0.5 for large area/priming? How does that sound?
Max

[rtfoe]

Hi Max, as Andy has said his 3.5 is fine for everything. The clogging happens when your paint is either too thick, not stirred properly or the pigments are just too course. Seriously you can spray primer from 0.2 up to 0.5...it all depends on whether you want the job done quickly or spray layers and lines of the primer until an even coat is achieved.

I know the airbrush seems like some dentist tool but it's easy to use once you've got the hang of it. You can only learn from mistakes. Take a look at Ross's Stuka for instants, he's still learning the fine lines but has found a way round it with results that even I would be proud of. He's done a great job of pre-shading with the airbrush and that can only be done with an airbrush.

Cheers,
Richard

[Guest]

Hi Max, as Andy has said his 3.5 is fine for everything. The clogging happens when your paint is either too thick, not stirred properly or the pigments are just too course. Seriously you can spray primer from 0.2 up to 0.5...it all depends on whether you want the job done quickly or spray layers and lines of the primer until an even coat is achieved.

I know the airbrush seems like some dentist tool but it's easy to use once you've got the hang of it. You can only learn from mistakes. Take a look at Ross's Stuka for instants, he's still learning the fine lines but has found a way round it with results that even I would be proud of. He's done a great job of pre-shading with the airbrush and that can only be done with an airbrush.

Cheers,
Richard

Thanks for all that detail and very useful information!
Max

[Dave Ward]

Max,
the smaller the nozzle - the less paint goes through - for an overall coat of a large area, then a large nozzle is appropriate - it's not that the small nozzle won't do it - it'll take a lot longer.
Also take the pressure into account - when I'm using the 0.2mm nozzle I drop it to around 1bar ( 15psi ) - other nozzles, I use 1.75 bar ( 25psi ).
My advice would be to get some blank card ( inside of cornflake packets ), and practice with the nozzle sizes & pressures. At first I would use ink, to remove the consistency mix from the variables. After a little practice, you can try out thinning with actual paint- a whole topic of it's own!
Dave

[Tim Marlow]

Wot Dave says!

[Guest]

Thanks both! With any sort of luck I’ll start playing this weekend. I’ll update as and when. I’m really liking this group!

[stona]

I tend to think that airbrushing tends to get over thought.

I use two airbrushes with nozzles so similar (0.3mm and 0.35mm) as to make no difference.

I spray enamel paints at 35-40 psi, whatever I am doing.

It works fine for spraying freehand detail even at 1/72 scale.

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My preferred 1/32

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Or even an occasional foray into enormous 1/24 scale!

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Pretty much one nozzle size, one pressure, one paint system.

Cheers

Steve

[JR]

Well there you have it Max.
Hope you post some photos of your tests. Think it will be of interest to everyone.
The main thing is its supposed to be fun !
John.

[Guest]

Well thanks for that Steve, a point well made! And as you say John, there you have it. Tomorrow could be the day. I haven’t got my new mask and booth yet, but if I’m just spraying ink or coloured water it won’t matter. What’s holding me up is clearing some space to work. I’m a self confessed hoarder, and I’m trying hard to be ruthless, but throwing away anything that has monetary value is hard! But enough of my problems; watch this space!
Max

[stona]

No worries.

The 'over thinking' also puts people off. The thinning of paint is not absolutely critical. I used to be a chemist, I know what exact measurement means, and thinning paint for spraying it definitely is not!

You just need to experiment to find a consistency which will give the coverage you want, and pass through your brush freely. In my experience almost every pot or tin of paint is different, so giving ratios is pointless. Experimentation and experience are the only way to get it right most of the time. I do it by eye and the look of the paint in the cup. At the risk of sounding like a smarty-pants, I honestly don't remember the last time I got it far enough off to cause any problem

Don't be afraid to up the pressure you spray at. I was originally, many years ago, given some lessons by an airbrush artist rather than model maker and that is where I learned to spray at the relatively high pressures I use. Many airbrushes won't even work properly at the pressures I see touted about on some modelling forums!

Once you find the magic formula for the consistency of the medium you are spraying and the pressure you spray at, stick with it. There is no need ever to alter it and potentially provoke all sorts of issues. I continually see people advocating extra thinning and ridiculously low pressures to spray Luftwaffe mottle for example. Bollocks! I've been spraying it for years in exactly the same way as I spray everything else.

The acres of camouflage on the 1/24 Spitfire float plane were sprayed in EXACTLY the same was as the squiggle on this little Ba 349 Natter.

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Good luck and have fun. After the initial learning curve you will find that airbrushing is not a dark art, in fact it is a doddle and great fun.

Cheers

Steve