Frustrated airbrush n00b

Tools, Techniques, and Reference Materials Painting and airbrushing
1

Hey guys. I have a new problem regarding my airbrush that I find both interesting and frustrating.

First off, it’s an Aztek A480 airbrush. I am using an Aztek AC200 compressor.

Last night was the second time I’ve tried to spray Model Masters Acryl gray primer. I thinned the primer appx. 3 parts primer to 1 part Testors Acryl thinner. I put the mixture in a gravity feed cup and set the compressor to 16psi. I am using the black, higher flow nozzle that should be for acrylic paint. I rolled the paint flow roller all the way to the left for a closed position. I held down the trigger (without moving it back) and adjusted the paint flow until a little bit of paint started to spray out of the nozzle.

At this point, everything seemed great. I sprayed the primer for about 1 minute, and then the pain flow stopped. So, I tried to set up the process again. I rolled the paint flow to the off position, and slowly opening it again until paint comes out. This time, nothing comes out. The only way I can get it to start spraying paint again is to pull back on the trigger and put it into double action. The paint spray works for a while at that setting too, and then flow stops again. While in double action, I get a lot of bubbles in the feed cup, which I thought was an indication of a leak. I don’t know why it would not do that in single action mode though.

Anyway, so all of this leads me to believe somehow the primer is clogging up the nozzle. So, I cleaned the airbrush, thinned the primer more, and tried again with the same result. This time however, the primer was obviously too thin and was running all over the place when sprayed. This same thing happened the first time I ever used the airbrush, when it was brand new.

So, is it something I’m missing? Thinning ratio incorrect? Wrong nozzle? Bad form on my part? Should I not try to airbrush that primer? I haven’t tried normal paint yet because I’m getting frustrated just laying down the primer. When the airbrush sprays correctly, it’s a lot of fun. That only lasts about a minute though.

2

Well, IMO, in the first place you probably did not need any thinner, since primer tends to be thinned anyway.

You see, more thinner makes the paint dry faster, clogging the air brush sooner.

Also, primers tend to be a flat color, with more solids then a gloss (second only to metallics), and are prone to clogging a nice internal mixing airbrush anyway.

And then acrylics tend to dry faster then enamels, which make them even more of a pain for spraying.

So I would suggest you get a simple, cheap, rugged, external mixing model airbrush, and first try the Testors acryl without thinning, since they claim you don’t need to in the first place.

This is the model they sell at Harbor Freignt under their Chicago Tool label,http://www.modelexpo-online.com/ and others have it under their label as well, including Badger, , etc.:

Go to fullsize image

Tom T [C):-)]

3

I share your frustration, sounds exactly my experience a few years ago. Acrylic dries fast and will tend to dry on the tip - even with the acrylic tip. If you tryied spraying on the ‘tan’ tip, it would be even worse, it will clog very quickly. While thinning will help, if you stop spraying for a few minutes, the paint will dry. The bubble indicates a clog.

Here’s what I’ve done to overcome these issues. I use Tamiya acrylic paint thinner instead of Testors, as Tamiya’s thinner contains a retarder to makes the acrylic not dry so quickly. Alternatively, you can go to an art store to by acrylic paint retarter. A few drops should do.

After I’ve stopped painting for a few minutes, I always first try spraying onto a scrap cardboard to make sure the paint hasn’t dried. Even it has just partially clogged, it may splatter. if it has clogged or the splatter continues, I dip the tip in water and move the roller all the way to the right. This puts it in single action only and at maiximum pressure. This usually unclogs any dried paint and then I adjust he roller to where I want to be.

It does take a bunch of practice to get this right. But it keep at it and it will come. Hope this hellps - it

4

Thanks for the suggestions, guys. I guess I still don’t know whether to thin or not. I suppose I’ll have to try without thinning, since that hasn’t helped. The nozzle seems to get clogged up during spraying, not so much if I let it sit for a few seconds. I never get to the point to actually let it sit. I’ll probably try regular paint too, and say f’ it to the primer.

5

JUST MY C CENTS AS I AM NEW TO AIRBRUSHING I HAVE USED THR TESTORS PRIMER WITHOUT THINING AND IT SPRAYED GREAT I ALSO HAVE THE A 470 A TRICK I HAVE LEARNED I TO HAVE A BOTTLE OF H20 HANDY IF YOU HAVE TO STOP PAINTING FOR A MIN LEAN THE PAINT CUP AGAINST SOMTHING SO THE PAINT DOES NOT LEAK OUT PUT ON THE H20 CUP SPRAY THRU IT FOR A MIN UNTIL YOUR READY TO PAINT IT WORKS FOR ME

6

I have had problems with my Aztek 470 as well…

Questions:

Also, how were holding the airbrush, was the paint allowed to flow into the airbrush from the cup?

Was the tip of the nozzle clogged with paint?

How long have you had the airbrush and how much have you used it?

What are the condition of the nozzles?

What is your cleaning regimen?

I recently had 2 nozzles go bad on me and they had to be replaced. The broken nozzles looked good visually but leaked and spattered paint all over the place. Another thing, air bubbles in your color cup is NOT good. You could have an airleak, which I have read is not uncommon in these airbrushes.

I would try airbrushing some water through the airbrush and testing for leaks and seeing if you can duplicate the problem with water. If there is a problem spraying water, odds are it’s not the paint. This is how I found out on my 470 using a siphon jar, the airbrush cuts out mid-pass at 23-27 PSI using water.

7

I went to solvent based paint because the water base stuff cloges the airbrush

Bill

8

Just a point of forum etiquette, when you type in all caps it implies that you are shouting. Please unlock your caps lock and use the shift key so you’re not typing in all caps. Thanks.

9

I’m guessing it’s the paint. I didn’t get a chance to try again last night, but I’ve used water as well as airbrush cleaner and both spray perfectly fine. No clogs, splatter, etc. I’ll do some testing this weekend and let you guys know if I’ve smashed my Aztek airbrush or not. I should have done more research and just got a simple, single action Badger or something.

10

BTW, the model I am suggesting is also external mixing, meaning you do not have any internals to clog up, as with the nicer ones.

I just soak the brass parts (they come right off easily) in regular fingernail polish remover and a toothbrush, if I get a stubborn residue build-up.

They run $7.99 at Harbor Tool, often on sale for around $5.00.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=47791

These do well for general spraying, as you would with primer, leaving your internal mixing, double action for more detailed work.

Cheap enough to keep a spare or two, as I do.

Tom T [C):-)]

11

Thanks for the airbrush suggestion, Tom. I was near a Harbor Freight today, but didn’t have the energy to stop in. It was a long day of shopping for me. Good thing though, I found a great LHS near my office that will suit my local needs for supplies just fine.

I had better luck tonight with the airbrush. While I was at the LHS, I picked up some Tamiya thinner, X-20A, and used that to thin my paints (thanks to a suggestion above). I decided to skip the primer this time and go straight for some color. I used a 4:1 ratio of paint to thinner (still using the MM acrylics) and upped the paint flow of the airbrush a bit. I was actually able to lay paint like I figured I should have from the beginning. The nozzle did start to clog up a bit, but each time it did I just dribbled a little Testors acrylic cleaner on the tip. I sprayed off project until the paint started flowing again.

So, tonight, I can say Nate:1, airbrush:15. At least I’m gaining.

As a side note, I’ve still yet to try paint on my model. I’ve been working on a Luftwaffe camo scheme for a glass Christmas ornament for the tree! [;)]

12

Glad it’s starting to workout for you, just keep at it, it gets easier!

13

Congraduation, Waikong, for your cutaway ShindenKai making the cover feature on the Jan 09 issue of FSM. I am afraid that my skill will never make it as easy as you showed. But it is inspiring to see your featured article.

BeerGremlin, I apologize for hijacking your thread.

14

No worries, keilau. I painted the base coat on my BF 109 today and it worked out perfectly. It is starting to get easier!

15

Keilau, thanks for your kind words.

BeerGremlin, I know I didn feel it getting better as quick as you are when I first started airbrushing - so I think you are making major progress.

16

Well guys, I have a new question now. Everything was going along swimmingly with painting my Bf 109, thanks to your help. But, once I got to the point to do a little more fine detailing, I hit a new snag. While I’m spraying a large surface, I usually keep the trigger pressed down constantly while going over the model. I needed to do the little blotchy camouflage on the Bf 109, and every single time I stopped spraying, the nozzle would clog. So, every 3 seconds I had to dip the nozzle tip in some cleaner to get paint to spray again. I’d then spray on some scrap until just paint and no cleaner was coming out, move the airbrush to my model, and then no paint would come out.

So, I poured a little cup of cleaner to dip the nozzle in every so often. When I dipped the nozzle into the cup, with no pressure on the trigger, air bubbles were forming in the cup.

So, here’s my next series of questions.

One, when my airbrush is just sitting idle, the compressor makes no noise, which I would assume is normal. The air pressure is constant at that point and appears to have no leaks. Although, I still assume there is one, just a very slow leak at the nozzle. Is that normal?

Two, while I’m airbrushing, the compressor clicks on and off constantly. I would think it would stay on constantly to keep constant airflow, but it doesn’t. Is that normal? During my tests of spraying nothing but cleaner, each time the compressor would click on I’d seem to get a surge of air through the airbrush, causing a slight increase in paint flow. That doesn’t seem right to me. I didn’t notice that when spraying a large base coat, but definitely did while trying to do detail work.

Third, I noticed a small air leak where the nozzle mates to the airbrush. How much pressure am I supposed to use to tighten the nozzle on an Aztek airbrush? I’ve used enough to not want to do more, but I might be too gentle.

This airbrush has given me more headaches than it seems to be worth. It sucks when I have the artistic ability, but obviously not the airbrush experience.

Any help would be appreciated, but this is more of a vent than anything. Of course I’ll be trying again tomorrow. :slight_smile:

17

I was annoyed enough after last night’s airbrush session that I ordered a Badger 200G to see if I have better luck.

18

Though I’m not at all familiar with yor compressor, I believe that it has an “on demand” switching setup, meaning that it only runs when you press the trigger on the airbrush. When there is sufficient backpressure in the air line, it switches itself off. When you depress the trigger, the backpressure in the line falls away to a level wher it switches the compressor motor on.

As mentioned above, the compressor motor switches on and off “on demand” depending on the backpressure in the air hose. This means that the motor should be running when your trigger button is down and should stop running a moment after you release the trigger.So there may be a brief moment when there is residual pressure in the hose and the motor kicks in where you may have a slight overpressure.

If you are using a double action airbrush, the solution is as simple as pointing the brush away from the model when you press the trigger, allowing the pressure to stabilise and blowing any excess paint off the tip of the needle somewhere other han onto the surface of youtr model, minimising spattering.

19

Thanks for the reply, Phil. When I’m spraying, the pressure never stabilizes. The entire time I’m holding down the trigger, whether for 10 seconds or 10 minutes, from start to finish the compressor is going on, off, on, off, on, off, in appx. one second intervals. Is that normal?

20

Do you have a pressure regulator, to see whether or not you are provided with a steady stream of air?

My new compressor also goes through the on-off cycle, but it is not an issue. I don’t know, from all you’ve explained, I would have saved myself some money and ordered a new Aztec tip, and thinned my paint down further. It just sounds like you probably have some paint dried up inside the tip already, and are just using paint that is too thick. I’ve used an Aztec airbrush for years, and have never had issues like you describe, unless one of the two (clogged paint, unthinned paint) conditions were met.

For those Aztec tips, it is imperative to keep the spotless. After each painting session, I immediately break them down into their two components and dunk them overnight in Windex (I only spray acrylics)

I also sometimes had air leaking around the area where the tip meets the airbrush body. Truthfully, it almost always leaks a bit, but enough that in a full cup of paint, i’ll only lose a drop of it. Again, clean your airbrush, clean your tip, or preferably get a new one, and tighten it down enough. Use the little key they provie you with, and make sure you get a good seal on it. Don’t overtighten, you can break them, but I haven’t done so yet.

Also, try Tamiya acrylic paint. Also thin it. I recall the first time with an Aztec airbrush, I used a Testors acrylic gloss coat on something, and didn’t clean it out immediately. Suffice to say, I was never able to use that tip again.