Acrylic painting through the Airbrush

[Rittersbach]

Hello all:

I am having a major problem with shooting acrylic paints through my airbrush. I have a badger crescendo 175 and am using a paasche airbrush compressor. I dont have a moisture trap or a psi regulator. My problem is, I am thinning artist tube acrylics with water. I stirred with a stick and let what small air bubbles were present dissipate. The mixture is rather thin so I didnt think I'd have any problems, but these pics show the result. It's almost like the water is totally separating from the paint. I did a search and found a thread Stephen Lawson wrote. I will try the blue windshield cleaner and a drop of soap. Will this solve my problem? Is my mixture too thin? I had this problem with my old badger 150 too and stopped using acrylics because of that. Can anyone figure out what my problem is. Thanks!!

[Brad Cancian]

Hello there Rittersbach;

Artists tube acrylics are thick, require thinning and are more so designed for use on a porous medium such as paper and not plastic (which is probably why the paint is beading on the plastic surface).

The only thing that I can suggest is using acrylic paints which are dedicated for plastic models (Tamyia, Gunze, Model Master etc). I do and I have found no problems spraying these acrylics.

Regards,

BC

[mgtaylor]

Dear Rittersbach

I am familar with the syptom. You've anwsered your own question. Don't throw away the paint throw away your compressor or else GET a Pressure regulator.

Your pictures bring back Sweat Beading Memories of me in during a nite in my mother in laws garage where I was able to set up a paint shop for the nite. Me and a Revell Spad which would NOT Take any color form a bottle of Polyscale. That was AFter I figured out why the enamel thinnier was makeing pretty floating lumps of paint in the jar when I read "Acrylic" Paint thin with water.

I too was using a PAshce VL Dual Action and a basic little badger air compressor without a regulator either. I spent hours spraying while my gun jammmed with dry paint. Too thick layers of paint sprayed too long in one area made beads like yours or tried in mid air before even hitting th epalastic. Hours and coats upon coats it took to get the French yellow to cover.

Here it is in a NUT shell , Two things:

1.) Take a light grey FLAT enamel, thin the heck out of it and spray away ALL over everything you intend on painting period. I start with the parts sprues straight out of the box and coat everything still on the sprue.

Water based colors "Stick" / "Grab" better to a Flat surface the micro abrasive surface which causes it to look flat allows the Acrylic paints to hold on to better than bare Oil based plastic.

2) SOunds too simple to work BUT IT IS AND IT DOES. LOWER and STEADY That Air OCmpressor AIR Pressure. 15 psi +/- 3psi. !!!! I was window shopping at my local Target store and in the Auto section was a cheap 1 1/2 Gal Holding tank Air COmpressor with a regulator knob to control output pressure. NEVER have HAD A Problem since works like a charm.

ALso a few drops of Isopropal Alcohol will BREAK the SURFACE tension of the Water which will instantly pop those air bubbles and allow the paint ot flow smoothly thru the gun.

High Pressure creates Heat which dries the micro scopic beads of paint leaving your gun. It also collects on the internal parts clogging it up. A low air pressure with a thinning agent to retard the water's surfacr tension makes everything work smooth as butter.

YOurs MIke

[Wind In The Wires]

You can get a portable air tank and a regulator at your local auto parts store and plumb them to your compressor. Pump the tank up, turn the compressor off and then spray with the regulator between the tank and the airbrush.

Yellows and gloss white must be sprayed over a primer.

Get a tupperware style box and use it to wash the sprues before priming with dishwashing liquid, rinsing well. This will remove most mold release compounds. Mold release compounds are sprayed onto the mold before molding to help the parts separate from the mold when it opens and some of it transfers to the molded parts.

I'm just a hacker with plastic models but these tips picked up from others have helped me out considerably.

[StephenLawson]

Greetings all;

Very sound offerings here. I use several of the methods described. Adding a drop the antibacterial soap does a great deal to break the surface tension of acrylic paints and prevents contaminate bacteria from ruining a bottle of paint. It also tends to use-up less volume than Isopropal Alcohol. distilled water and anti batcerial soap or just Isopropal Alcohol would probably be your best answer. All paints run through an airbrush should be about the consistancy of milk. It sounds like your paint is hitting the surface too "wet' as well. Airbrushes should deliver the paint with almost all of the carrier evaporated. I have worked out of a cup and bottle. This means if you mix your paints you are going to use you tend to pay closer attention to the mix. Otherwise you need to stir the whole bottle to get the right consitency.

I have an attachment to my motortool. Essentially it is fine mesh plumber creen for a faucet ariator with a thumb tack pushed through the center. It is pushed into a section of model sprue that is chucked into the variable speed motortool. 10 seconds tops and I have a well stirred bottle of paint with very little effort. Once stirred its easy to tell how well you paint will cover. Its alway good to have a fresh jar of the same paint nearby. That way you can add pigment as needed.

Running your airbrush in this manner for acrylics you will need to have some cotton swabs soaked in either water or alcohol to keep the pigment from building up on the spray tip and needle. swab it between shots and you will have few clogs.

[Rittersbach]

Thanks everyone for the great suggestions. I will use them and see what happens.

[drbubba43]

Test the alcohol / paint mixture before you mix it. I've had some acrylics react badly with alchohol. Turns them into a chewing gum like consistency.

Rare, but frustrating when it happens.

Never had any problems with the dishwashing soap, which is what I usually use.

[ChrisSavaglio]

All good advice, so far. I spray acrylics almost exclusively. Here are my thoughts....

As Mike said, 15 psi or so works well. I definately wouldn't go over that.

As for thinner, try different things. I'm sure the brand of artist paint you're using has a thinner made specifically for it. Acrylics aren't necessarily water based. In the automotive world, there's acrylic lacquers that require specific thinners for them to work. Try windex(ammonia based window cleaner), isopropyl alcohol(get the highest alcohol content you can find at the grocery or drug store...usually 70%), tamiya acrylic thinner, poly scale acrylic thinner and even lacquer thinner.

Test them out. Worst case is you have to clean the airbrush out a bit.

For consistency, go for about the same consistency as whole milk.

And last, I would probably switch to a modeling paint. I've never had any luck with artist paints as far as airbrushing goes. Oils are great for weathering and washes, though. Model paints have a different chemical makeup than traditional artist paints. They are made to work on plastic and shoot through an airbrush.

Best of luck. Hopefully you can get your current paint to spray right. I'd hate to see you throw it away.

Chris

[drbubba43]

The Wal-Mart near my house carries 91% alcohol.

409 also works well and I've never had problems with it. I use it for brush cleaner also.

[trackpad]

Hi,

I've been experimenting with a few brands of acrylic paints: Tamiya, Lifecolor and Gunze. I've not had much luck when I use the 70% isopropyl alcohol (slow drying, runs, etc), but had much better results with the 99% version. I understand that 91% IA is also available. Seems the higher the alcohol content/percentage, the better the results. Can anyone else confirm this?

Cheers,

Gary