Airbrushing acrylics woes

-Greg, I'll keep that in mind on mixing Vallejo products with Vallejo acrylics. Vallejos AB thinner and Testors acrylic airbrush thinner smell like pretty much the same solution to me an appear to work just as well as the other which is why I started using the testors (not to mention more volume). I'll let you guys know what's up once I get a new nozzle. I will also try to post up some spray patterns at various pressures so you guys can see what I'm working with.

Just FYI,

Vallejo retarder medium is not designed for airbrush use. It has something to do with hand brushing if I recall. It'll make things much worse in a airbrush (in my experience anyway).

In my experience Vallejo product nomenclature can be confusing sometimes misleading. I'm not throwing stones at Vallejo, they are my go-to acrylics.

One other thing just came to mind. If you want to mix anthing with your Vallejo acrylics (airbrush thinner, flow enhancers, etc) my two cents would be to stick with Vallejo products only.

 

I agree with pressure reduction, most of my acrylic spraying is at 15-20 psi, regardless of paint brand.  Currently I use Tamiya acrylics, thinned with X-20A. For additves I use Liquitex Flow Aid or Slo-Dri.

I keep a small tin of alcohol on the bench and a Q-tip at the ready, for a once in a while swipe of the needle/nozzle end. It will tell you when it's time. If you use a pressure regulator, should the AB act up a quick spray at 25-30 psi, will help to get some of the build up and partial drying/thickening in the nozzle interior blasted out.

For the most part I keep the AB relatively close to the surface, that reduces the tendency for particles to partially dry on the way to the object. Also the reduced pressure will prevent creating a fine mist that can place gritty, dried bits on the surface.

Patrick 

Gentlemen, thank you very much for all the responses.

-hypertext I did a lot of research on the internet about airbrushing and the HP-CS in particular as it was the first gravity fed brush I've ever used. I read basically what you said that 15-20 PSI was around the pressure that it should be operated at. In my experience there was always something off with the spray pattern when I would shoot at the pressure. Now this may just be my lack of experience with an airbrushed.. but it seemed to me like a lot of what I would describe as overspray. By that I mean if I was spraying a centered pattern there would be a while defined center but out side that there would be a lot of speckles similar to the "dry spray" you mentioned. I guess I don't have a real reference to what a "normal" pattern would look like for an Airbrush but I figured it would be a lot tighter and more accurate than it was. Then again I was not shooting as thin as you were suggesting.

The other issue I had with shooting at a lower pressure like 15-20 PSI was not being able to spray fine details very well, i.e. panel lines on armor or aircraft for shading as well as creating shadows on the minis that I game with. I would have a much wider pattern as I got close to the component that I was working on and not the tight fine pattern I needed. I feel it got a little bit better when I shot 25-30 PSI. "Spidering" is another issue I had when going really then and getting the airbrush nozzle close to whatever model I was shooting. Any tips for that?

I have some Vallejo medium retarder that I try to mix in with the paints I brush but it is very thick and I'm not entirely sure it does the job it's supposed to do. I'll try and look at some of those brands you mentioned.

 

-Greg I will absolutely check for some coupons because the last time I went to hobbylobby the nozzles seemed much more expensive than they were online.

All great tips, and one more I can add is thinning with pledge future clear product - as long as a gloss surface is part of your air brushing stage.  Also, keep a wet brush handy to wipe the needle tip if paint starts to dry on you.

regards,
Jack

I think you need to get your needle/nozzle replaced as Don said in the other thread, get that air pressure down a little bit as Hypertex mentioned above, and start anew.

The dry tip is probably never going to go away 100% spraying acrylics, but with some tweaks of proper products and ratios you will be able to make is almost go away.

Do hope you let us know when you get the new tip/nozzle. BTW, Hobbylobby usually stocks them. You can get two coupons, make two trips in if you want to be a nut like me.

 

What you are describing is called "dry spray." It seems it is quite common for enamel users who switch to acrylics to experience this. The solution is threefold: 1) spray closer to the model, don't be afraid to get in close; 2) add more thinner--when you think you've added enough, add a bit more; 3) reduce air pressure. There is no magic number that works for everyone, but I usually spray between 15 to 20 PSI.

You are doing the right thing in starting with the manufacturer's recommended thinners. But you could try a little retarder. Use a liquid retarder and not the gel kind. I use Winsor and Newton Galleria retarder. It even works with Tamiya paint. I would suggest adding no more than 5 or 10%.