Nozzle size - what’s it all about?

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MarshMan

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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

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

Mr Bowcat

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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).
 
M

MarshMan

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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?
 
M

MarshMan

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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

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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
 
M

MarshMan

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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

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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
 
M

MarshMan

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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

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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.

IMG_1207.JPG

My preferred 1/32

IMG_0968.JPG
Or even an occasional foray into enormous 1/24 scale!

top.jpg

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

Cheers

Steve
 

JR

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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.
 
M

MarshMan

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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

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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.

SRQ_web.jpg

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
 
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rtfoe

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There you have it Max...it's not rocket science so knock yourself out. :tongue-out3:

Cheers,
Richard
 
M

MarshMan

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Ah Steve, I like the way you tell it as it is! Reading on the lines, as well as in between them, has been most instructive; liking your work!
I’m just having a break from trying to clear some work space to make a start, but it’s worse than I thought!! I’ve got two sackfuls of stuff and there’ll be another couple yet I reckon! It’s years of ‘bits and pieces’, you know, the the sort of stuff that’ll ‘come in handy even if I never use it!’ But, on the bright side, I’ve found some handy small artists brushes along with oil and acrylic paints I’d forgotten I had! Back to the grind after a coffee and cake; I have to keep my strength up!
 
M

MarshMan

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While taking my break I just found this pic, on eBay of all places. For those who don’t recognise it (and I suspect that won’t be many) it’s an SE5a. It happens to be the best I’ve found so far. Thought I’d share.
C7934789-64E0-49AF-B2F5-5EB83E96D03D.png
 
M

MarshMan

Guest
Well, I’m on the verge! Sufficient space now made, my new cutting mat put down and my compressor connected for the first time. I first had to cut the moulded on plug off, because it wouldn’t go through the plug hole on my bench! My first half panic came when I couldn’t work out which way the adjuster moved to reduce pressure, but having remembered that stillp Peter had given me a manual link, I checked and found that it’s counter intuitive, and indeed counter clockwise, to reduce the pressure! So having checked that the auto tank pressure cutout works, and that when I press the trigger, air comes out, I decided I’d leave the inaugural spray until tomorrow. The excitement is almost palpable!
 
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