Hi All,

Just sat and calibrated my compressor yesterday for use with my airbrush. These are the specs to which I have set it now:
1. It cuts off at around 45 PSI(that is, as soon as pressure in the tank goes to 45, the comp switches off)
2. It cuts in at around 15 PSI(i.e when pressure drops below 15). However, I tried a lot to adjust the pressure differential so that it cuts in at 20, but to no avail..

I've started practicing use of the AB using fountain pen ink thinned with water, and am spraying on a poster sized sheet of paper(to save on my precious acrylics and also models from looking like something that spent the night in a swamp:)!). It's a dual action brush BTW !

OK, here are my qns after about 2 hrs of practice:
a. For spraying acrylics, just how close do you need to get to the model? I make Aircraft, but will be foraying into Armor laterz..
b. How much PSI would be needed? Is the settings OK? I saw from a lot of other posts that they use 20-30 PSI, so I've done the same.
c. For practice purposes, I need to draw lines on the paper between dots. Do I need to increase the pressure, or can I work at this itself? Also, do I need to keep the AB closer to the paper while I do so for a clean line?
d. Again for drawing lines, for thin ones, do I need to pull the trigger only about 1/2 the way back? Or is it OK if I go close in and just half cock it?
e. In your experience, how much thinner/paint ratio do you use for acrylics? I've seen 40/60 here somewhere.. Also, how much time will it take to dry up?
f. Do I need to work like a maniac at full speed to avoid paint drying up/clogging in the AB tube, or will it be better if I use retarders?I am using conventional artists acrylics here, like the ones made by Liquitex. I'm really worried sick about the paint clogging up my AB, and it's pretty damned %*&$^ expensive here..(the AB, not the paint!)
g. Finally, one last qn : again, for drawing thin/fine lines, do I need to tighten up on the needle so that more of it protrudes at the aperture? Currently, it's jutting about 2-3 mm out of the aperture when it's not cocked.

Thanks a lot for your patience so far.. I am sure some of you, if not all, would have faced these teething problems when you started out with your AB !

Rgds,
BP.

I think answers to most of these questions will come when you TRY these things out on that big paper sheet of yours. If you try to find the settings to make a thin line, just practice on that paper, try different distances, pressures and triggering. Just look at the line you painted: Which part is the desired result? And try to do it again. It helps if you change one setting at a time.
Thinning, pressure and airbrush settings are more or less about individual preference. They can also vary a lot depending on what you´re trying to do. With acrylics I have faced the drying problem. A second after spraying the model it´s dry, but I really have to clean that airbrush instantly! It´s VERY difficult, if not impossible to clean an airbrush if acrylics dry in there.
I´m not a very experienced airbrush painter, and my best guide has been the gut feeling when I feel that I´m doing it right. It´s not even possible to have that instant connection between brain and hand without lots of practice...

Maybe not much help but good luck anyway!


Toni

Damn!!!! And I thought using enamels was a pain in the *** when I started using a plain paintbrush in the beginning.

Thanks for your op, Envar.. anywayz, as I said earlier, I will be using retarder, so hopefully that drying-in-a-sec won't happen ...

Any more people out there having a bad experience with acrylics AB'ing? (Even good ones will do ! )

BP

One thing about your testing - I would recommend testing on a piece of plastic to work on the thinning ratio. Reason being - when the paint hits the poster it will be absorbed because of the pourous nature. Then when you move to plastic the paint may be too thin and run.
Outside of that,
When I paint aircraft I usually spray about 15 - 20 lbs and have the brush about 10 - 12 inches away.
The settings for trigger pull, needle position etc. are going to be based on the AB you have. Realize that each time things may be slightly different so it is always a good idea to take a couple of practice runs each time.
You are being concerned with all the correct things and within normal limits on measurements etc.
I would recommend spraying lightly and doing more coats rather than full on one shot style spraying. Its easier to add more than to take away.

Practice and Patience is the key.

Hi Slodder,

I'd like to first learn how to use the AB using ink and paper, and then I was planning to test the thinning on a dummy plastic kit which I have. That's why I'm going this way.

I'd like to know how much will come out of the Ab at different levels of pressure, and that I guess should be a good way to learn how to handle the AB.

One more thing, you paint at such low pressures, but still keep the AB 10-12in away? Doesn't that result in wastage of paint? I do agree about the multiple coats part, but I'd say it would be a waste of paint .. my 2 cents.. ! Also, if you use acrylics at that range, wouldn't the paint be dry by the time it hits the model?

And about spraying on plastic, I intend to prime the kit first, and then paint. this should help the acrylic to get a bite...

Well, gotta get some practice then.. Am still waiting for some light on acrylic AB'ing...Any takers?

BP.

Hey BP ......all the best to you with your airbrush.
The best advice I can give you is to sit down with your AB
and practice shooting paint at different psi level's, try different
paint thinning ratio's, and while doing these thing's, practice
spraying different shape's ( X's - dot's - zig-zag's - etc. ), even writing your name
with fine & broad spray's help with control and consisitency , with trigger position.
When I started this is all I did............self-experimentation and practice
is your best teacher.
- As far as shooting acrylic's .........NOT ME !
I have always airbrushed with enamels. On the contrary, I think they
are a lot easier to clean up and above all.........I can spray for hour's, and
not worry about my paint drying and clogging my nozzle and needle.
Once those acrylic's dry .......man, they are pain in the ass !
But everybody has their preference.
Good Luck & all the best to you.

- ralph

There should be one central airbrushing fact sheet since these questions come up constantly.

I have airbrushed with acrylics for over twenty years and there is no problem at all with it. The most important thing is to strain the paint through 10xx or 12xx silkscreening silk to remove clumps, impurities and keep the paint consistant. I thin the paint with water to a milk-like consistency and add a drop or two of flow enhancer or Windex. Also, if the paint will not strain through the silk it is too thick.

To clean dried acylics you can use lacquer thinner but be careful with any airbrush (like Paasche) that has rubber o-rings since the lacquer will eventually eat it up. Of course replacements for these cost next to nothing.

Probably the most important thing about airbrushing is to take your time and "mist" the paint on. It is important to practice using a uniform motion to your wrist as you move the brush back and forth. When you pass over the model with the airbrush let your hand go beyond the model with each pass.

Give each coat a chance to dry before adding more. You will need to build up the opacity instead of trying to do it in one coat. If you spray too close you will get spider puddles: little blobs of paint that shoot out tentacles because of the pressure from the airbrush. By misting at around eight to ten inches away from the model with constant motion in your hand movement you will not have any problems. Remember to spray at every angle so that you get all the undercuts in the model.

The best possible advice is to work slowly letting successive layers dry. Do not rush it!!!!

Another important thing is to use the right airbrush and/or right tip/needle for the job you are doing. There is a tremendous difference between the Paasche H3 or H5 and Paasche AB. The H3/5 is great for spraying large areas and the AB for fine detail work. The consistancy of the paint will matter to these aribrushes as well. Since the H3 has a wide nozzle it can handle thicker paint whereas the AB is a piston based brush that has to have extremely thin paint.

At last, some light at the end of the tunnel !

Screamingeagle, your point is taken. In fact, when i started off with modelling, I was using enamel paints with a paintbrush. However, at the time, I didn't have much knowledge(even lesser Net Access ), and I never used to thin my paints.

Even then, most of the stuff I did turned out pretty well, except for the canopies, which inevitably fogged up or had fingerprints on them at time of attachment. Stuff like weathering, washes, etc never even crossed my mind.

Well, as they say, experience is the best teacher, and I thought I'd do better justice to my kits from now on. I can afford to buy my own kits now(and not ask my dad to spend on them ), and I'd like to tap the experience of people like you and BobTavis to do a good paint job.

Bob, I'd like to know if you use acrylic retarders for your paints. Is it really useful?

Thanks for your help so far...

One more thing : will you get the same kind of feathering effect between camo colours when you spray with enamels instead of acrylics? Or is it more sharper with acrylics?

BP.