Pulsing spray

[Sharknose]

Evening.

I'm spraying a bronze tiger Typhoon, copper and orange Tamiya acrylic mix. Although I'd thinned, I had about an 80/20 paint to thinners.

The spray seemed to pulse,  steady air pressure,  needle say in the same position, paint seemed to not spray,  blast out then ease off, kept cycling round that way.

I thjnk it's just a case of needing to thin the paint more. I should have known better.  Any others experienced this?

The compressor and brush are fine. 

[Mike]

If you don't have a receiver/tank, you might be picking up the cycling of the piston in the compressor.  Usually a long hose will smooth that out, but maybe not this time?  If it's not a lack of receiver though, I'm not sure

[colin]

With your thinning ratio I wouldn't expect this, but I had problems with Alclad milspec paint doing this and it was because the paint was drying on the tip.

A blast by pulling the trigger back and it was fine for a few seconds then spitting, not sure if your getting the same as you say pulsing

[Sharknose]

I do have a tank and a long hose.

 

Sounds similar Colin, it kind of builds, then releases a spray then dries up. Repeats. Does feel like I need to thin it more. Metallic paint is more gloopy. I'll thin it a bit more, see what happens.

Edited May 26, 2019 by Sharknose
Additional info

[colin]

What size needle are you using, Tamiya metallics have quite course metalic flakes in them, may be blocking the nozzel

[Sharknose]

0.2. I started out with 0.4 but felt I had no control. Hmm. That's something to ponder there. Cheers Colin.

[Sharknose]

Tried it again, thinner, both nozzles, 0.4 better but I'll never get the precision I need. It's too wide and needs to be too far away.

Disappointed because it's making a pig's ear of something I've put some right hours in. 

Never mind.  Lesson learned.  No more Metallicas from Tamiya.

[Greg B]

On 27/05/2019 at 05:21, Sharknose said:

Evening.

I'm spraying a bronze tiger Typhoon, copper and orange Tamiya acrylic mix. Although I'd thinned, I had about an 80/20 paint to thinners.

The spray seemed to pulse,  steady air pressure,  needle say in the same position, paint seemed to not spray,  blast out then ease off, kept cycling round that way.

I thjnk it's just a case of needing to thin the paint more. I should have known better.  Any others experienced this?

The compressor and brush are fine. 

Reading this I think your thinner ratios are way out. Try at least 50/50 and turn down the air pressure. The thinner the mix the less air pressure needed to push it through. A couple of drops of Tamiya retarder in the  thinners wouldn’t do any harm either (or use gunze levelling thinners).

[Sharknose]

Hi Greg,

 

Yeah I thought that, thinned even further down to approx 50/50, same result.

 

I'll get this finished, then write it off to experience

[Schwarz-Brot]

This is typical behaviour I experienced with many waterbased acrylic paints. Especially Vallejo (Game Color, Model Air). Drying retarder helps quite a lot with those. Make sure it matches your type of paint!

[colin]

Try another brand, Tamiya metalic flakes in the small pots are way to large.

Their aerosol spray tins are better, you can decant them and use the paint through your airbrush, or Gunze super metalics/Alclad/AK extreme metal

[dnl42]

I usually thin paint far more than 80:20--more like 1:1. I tend to use my 0.5mm Iwata HP-TH for pre-thinned Alclad as I find my 0.3mm HP-CH a little sketchy with tip drying. Burping the 0.3mm airbrush helps, but that is disruptive.

 

I don't have a tank, and I don't experience material pulsing issues. 

[Sharknose]

Thanks for the tips. This is only my 3rd airbrushed kit so steep learning curve. 

1 step forward, two back. Esp when I plonked a clumsy paint stained nato black thumb print on a bronze wing.

 

Shakes head