Airbrushing success (but...)

[BarryW]

Aidan - the paint will be drying before it hits the surface. Try a drop of retarder in the paint cup or thin it a little more. If you use Tammy's own thinner it does include some retarder.

[Guest]

As far as the model paint products and their usages, I am learning plenty from the responses!!

Thanks!

Steve I see no reference to airbrush tip /needle size.

Generally (in my painting world) primers and clearcoats are much heavier products

that require slightly higher pressures

but more importantly require larger tip/nozzle sizes.

...I even switch guns to spray clearcoats.

For better clear finishes, wider sprays are necessary.

Having a dedicated gun for clearcoats might not be a bad idea.

I would choose something with a larger tip size (maybe .5mm?) and a wide fan spray ability.

I teach airbrushing, and the most complaint is sputtering and tip clogging.

And other than the obvious paint related reasons (eg paint too thick for too small a tip size)

the usual answer is the brush and its parts need more cleaning.

My rule is "if you think its clean, go back and clean it again".

Your work saving your "settings" is what I wish I could do.

Remembering pressure settings, mix ratios, etc will always come in handy.

[stona]

Aidan - the paint will be drying before it hits the surface. Try a drop of retarder in the paint cup or thin it a little more. If you use Tammy's own thinner it does include some retarder.

Exactly.

Not a problem with enamel paints

Steve

[BarryW]

LOL Steve, but they smell......

[Guest]

Steve I see no reference to airbrush tip /needle size.

Remembering pressure settings, mix ratios, etc will always come in handy.

My original post mentioned a 0.40 mm nozzle. I chose that to minimise blocking.

On remembering settings, I am easily confused and forgetful. So I make a table and write down the settings and the results. Here is an extract:

[ATTACH]58550.vB[/ATTACH]

Yes I know its obsessive, but otherwise I get into a muddle.

Today's tests, based on advice in this thread, were successful. I reduced the pressure. My standard setting (unless I get bad results in future) are now:

Vallejo Model Air Paint: 20 PSI thinned 10% with water.

Vallejo Primer "Acrylic-polyurethane" 73.600): 20 PSI thinned 10% with water.

Vallejo Gloss Varnish: 20 PSI thinned 14% (thinned 18% also worked).

I guess that using water (less volatile I suppose) rather than thinner reduces the opportunity for the varnish to dry on its way to the model.

Thanks for all the help.

[ATTACH]60412.IPB[/ATTACH]

[BarryW]

Steve - I would suggest the opposite, simply because of the retarder in the thinner.

You are very precise with your percentages - 14%!!!! How do you measure it out to that precision? I pretty much guess....

[Guest]

Steve if you are using Vallejo use their thinner as it has the same ingredients as their paint & varnish.

Aidan I bet your were to far away form the model & when it hit the particles as has been said where already drying. If that happens again try thinning with the paint manufacturers thiinners not water.

Subject of needle size & pressure. If your needle size is .4 you will get a larger amount of paint rhro. compared to .2 needle size

With a higher air pressure you will get more paint delivered than a lower pressure.

Near to the subject you will get more paint delivered to a smaller area than further away which will give more sparse coverage to that larger area.

All of which I have found is that you have to experiment to find the optimum.

On top of all of this is temperature of the paint temperature in the room how much you pull the trigger back on a 2 stage brush & the type of brush & paint you use.

Other than that it is not very complicated !

So my idea. Pressure less than 20 Vallejo Model Air thinned approx 20%. Thin "only" with Vallejo thinner. Keep temperature stable at the temp you will always try to use (summer difficult). Spray to begin at 6" form the model.

Then practice & experiment time & again. In the end you will find with time what works.

Very easy really !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Laurie

[Guest]

Steve - I would suggest the opposite, simply because of the retarder in the thinner.You are very precise with your percentages - 14%!!!! How do you measure it out to that precision? I pretty much guess....

But I was using water as the thinner. Does water act as a retarder?

------

18 drops of paint + 3 drops of thinner. 3/(18+3) = 3/21 = 0.14286 --> 14% (rounded). In this case, the result is near 15%, a comfortable figure like 5%, 10%, 20% etc., one of which most people would choose to express a guess. A near neighbour (like 14%) gives the (often incorrect) impression of accuracy resulting from great skill. My 14% is highly accurate as far as the maths go, but of course the relative sizes of the drops are unknown. So my figure should really be 14% +- 2 percentage pints --> 15% approx. But in practical terms I can accurately reproduce the result by simply counting drops which are likely to be consistent.

[Guest]

Steve I would forget the drops. It is what looks right. Fill the cup with paint part way put in approx 20% of thinners stir with a brush in the cup & that is it.

Nothing scientific at all. First coat I thin a bit more than 20% & put on a mist coat to get a foundation. It will also stop curtains forming in the next coat.

The drops are not accurate as a difference in temperature will upset any accurate scientific approach. Nor is 20% thinners it is what works for you your set up & the tmeprature & the RH value on the day.

I would for get about water as a thinner. Use the manufacturers thinner. Vallejo thinner has the same make up as the paint. Water will dilute the acrylic resin base of the paint taking away it's inherent properties the manufacturer has in built.

Before airbrushing the model I have an empty plastic water bottle that I use to spray a test before starting on the real thing.

Laurie

PS all above is using Vallejo Model Air.

[Guest]

Laurie. OK, I will use the Vallejo Airbrush Thinner. I have just seen a Flory Models movie in which he sucked up some thinner in a pipette to the 1 ml mark, then did the same with primer in another pipette, up to the 1 ml mark. (This gave an accurate but rather high 50% thinning). Then he used that second pipette to suck up the contents of the cup and squirt them out, several times, to mix it. Seems interesting, but you would have to use thinner to clean the second pipette.

[Guest]

Steve I have only used a pipette once then thrown it away.

Mix with a brush in the cup & you will not have any problems.

Flory is a very good guide but he is selling his stuff & gets a bit carried away. If you look at a lot of Flory when showing off his skills he pours paint & thinners into the airbrush cup without any measure what so ever except his feel for airbrushing.

As said by many here airbrushing is rather like, although a very long time ago, turning from a teenager into an adult a hard learning period where the skills of many things are tried tested gained honed & arrived at how it most suits you. No easy lessons no rocket science just pure perseverance & experiment. The best thing is to get that plastic drink bottle & practice until you get the feel of it all.

Laurie

[Guest]

I wouldn't recommend mixing in the paint cup full stop. You risk damage to the inner surface of the cup (the needle too) by possibly scratching it with the ferrule on the brush for one thing, for another and more importantly, you will not get a thorough mixing of paint and thinners, I've seen many videos where people decant paint then thinners and backflush to try and mix, likewise, this won't work either.

I mix in little plastic medicine dispensing pots, (chemist shop, ask at the counter, they're pennies and if you're a regular they might even give you a few for nothing).

This way you can see when the paint is mixed AND when the consistency is the skimmed milk translucency you're trying to achieve.

If you mix in a pot as you'd do in the cup, (especially so enamels), you'll see what I mean about not mixing thoroughly. The only time I'd decant into the cup is a paint that requires no thinning.

On the subject of retarder, it's a chemical which allows the dying process of acrylic paint, (used by silkscreen printers too), it's purpose is solely this and not thinning and it allows you to get a wet coat down before the paint dries.

[Guest]

Steve I have only used a pipette once then thrown it away. As said by many here airbrushing is rather like, although a very long time ago, turning from a teenager into an adult a hard learning period where the skills of many things are tried tested gained honed & arrived at how it most suits you. No easy lessons no rocket science just pure perseverance & experiment. The best thing is to get that plastic drink bottle & practice until you get the feel of it all.

Laurie

I absolutely agree. The learning process is very interesting. I believe that the subconscious mind (I'm not being spiritual here) absorbs information and later instructs the owner how to, for example, move his hands, both without him knowing. This is particularly true of craft work and even applies to, for example, learning to drive a car.

I now have 8 plastic milk bottles with an amazing psychedelic range of coloured designs!

[Guest]

I wouldn't recommend mixing in the paint cup full stop. You risk damage to the inner surface of the cup (the needle too) by possibly scratching it with the ferrule on the brush for one thing, for another and more importantly, you will not get a thorough mixing of paint and thinners, I've seen many videos where people decant paint then thinners and backflush to try and mix, likewise, this won't work either.I mix in little plastic medicine dispensing pots, (chemist shop, ask at the counter, they're pennies and if you're a regular they might even give you a few for nothing).

This way you can see when the paint is mixed AND when the consistency is the skimmed milk translucency you're trying to achieve.

If you mix in a pot as you'd do in the cup, (especially so enamels), you'll see what I mean about not mixing thoroughly. The only time I'd decant into the cup is a paint that requires no thinning.

On the subject of retarder, it's a chemical which allows the dying process of acrylic paint, (used by silkscreen printers too), it's purpose is solely this and not thinning and it allows you to get a wet coat down before the paint dries.

Apologies beg to disagree m1KS. No damage to my cup in 2 years. A new cup is about £4 for a Harder & Steinbeck. Also if you use a good brush with a long snout your get right down in to the forward part. Cannot see how you would damage the needle as only the hairs on the brush reach the needle & also the point part is in the nozzle which the brush cannot reach. Matter of interest I use a green scourer for my cup if it has stubborn paint on it. No damage at all.

Not had any problems with mixing in the cup it has worked perfectly for me. Also much cleaner & easier for me. Tried the mixing in a little container & found it a pain. Probably impatience you see.

But there you go horse for courses. Choose your course get used to it & you will be in the winners enclosure. It worked for me.

Laurie

[BarryW]

I am with Laurie on this. I too mix in the cup and find it works well. I always put thinner in first, then the paint.