Airbrush woes - paint dispensing

[God-Potato of Mankind]

Hello all, 

 

I have recently attempted to airbrush again. 

 

I got a new gun, set of vallejo air paints and cleaning station/fluid combo.

 

I have put 2-3 drops of Vallejo Yellow Ochre into the little urn thing, but no paint comes out?

 

I tried mixing with a drop of water and then SOME came out. I then tried a few drops more paint and then I got some coming out but it wasn't the smooth, coating spray I saw in videos. It was patchy, watery or just splots of paint. 

 

I'm not sure what is causing this, any ideas? 

 

Is my PSI too much? I see on the compressor it is 40psi but there's no option to lower this. Is it the paint needing thinning? I thought vallejo air didn't need it, but I wasn't sure.

 

Cheers,

 

Potato

[Khornestar]

I'm not an expert, but lately I've been using an airbrush quite a bit and have found some solutions that work for me.

 

First, is there really no knob to adjust the pressure? 40 PSI is very high, separate from the paint clogging issue. All other things being equal, 40 PSI should be blasting the paint out.

 

I use a thinner, at first isopropyl alcohol (worked decent) and then Vallejo thinner. I've heard of Windex glass cleaner being used to good effect, as well. I usually use a 2:1 or 3:2 ratio of thinner to paint for GW/Vallejo paints not formulated specifically for airbrush use. For thick metallic paints I use the second ratio. I'm happy with my results using that mixture.

 

When the thinner/paint are added, I mix them by holding my thumb over the nozzle and spraying air to force bubbles into the paint cup. Sometimes I use a brush to mix it up, but I hate losing that bit of paint the brush absorbs. That's how it goes sometimes, though. An even mix really helps me prevent clogging.

 

Best of luck!

[infyrana]

Right, I'm no expert, I've barely used my brush, but works great since I got a new pump - I still play around to get it right, here's some thoughts in case it helps.

 

Odd, could be that your airbrush is dirty, or that it's blocked, or that there's a dial that you haven't twiddled with - all factors you should review the moment you take your next look at it.  If none of that is the problem, regarding Vallejo paints, you could use their thinner, start with a 3-1 drop ratio and mix well.  It shouldn't be dry or gloopy etc, try a little more thinner if it still fails to work right.

 

Check the pump, check you aren't getting air loss or otherwise restricting the air flow (ie checking your brush for a dial).  Also check the brush for functionality (ie dry use it to make sure you can see stuff coming out).  You can also 'dry' run the brush, just get the clean airbrush, take it off of the air pump, and blow down the pipe manually, functioning the button for air flow on the air brush to test that it works ok etc.

 

You could also piece it all together and test with water, making sure you fill the little paint pot up so that there is no mistaking the fact there's sufficient liquid (water in this case) to be 'sucked' up into and through the brush.

 

Constant 40 psi should be fine if you get the paint mix right - but it's all about whether the basics of it are working first.  Be sure to test spray on some cardboard, keep the brush far enough away that you don't create heavy pools of paint, and check-spray before you hit anything else so that you can see if it's bubbling or flowing right.

 

Good luck, come back with more updates!

[God-Potato of Mankind]

Thanks guys. 

I will try it again on the weekend. 

 

The weird thing is, I can blast water & cleaner through it. Just paint doesn't go through :(

[infyrana]

Thin the paint out more until you find a working solution.  Ie, make it like milk, semi or fully skimmed milk, if that fails (since that's almost water-like), it needs further investigation.

 

I've actually gone the opposite way in using (what feels like a lot thicker paint) Vallejo Primer without a thinning agent at all (just some Flow Improver drops instead).  But I can get my pump up to 60psi, though it still runs fine and pumps paint at less than 40psi np, but the effect and covering becomes different as the pressure drops (so you have to keep an eye out).

 

Pre-mix the paint in a dropper bottle, make it thin as said above, test the brush, add the paint, spray evenly from 6-10 inches away, try in small short bursts tapping the air flow, and then try with longer bursts (so you can check how much pressure the pump drops by over time), and see where it goes wrong - feel free to make a video if you're that kind of person.  Then the experts on here can take a look (I hardly paint, but learnt a lot recently in trying to rekindle my painting output).

[Kaedes Nex]

A lot of people think VMA is "ready to go" and doesn't need to be thinned, which can be true in some cases, but generally you can and should thin it some more. VMA can and will clog if unthinned.

 

40 psi also sounds really high but without knowing your needle gauge, brush model, compressor, etc it's hard to say. There are painters who prefer to airbrush at higher psi and they have a setup that works for them. Others have setups that run best on 15-25.  The highest psi I've seen people paint at is 35 so 40 sounds like it might be too high.

[Daevyll]

Like others have said, when I read your post 3 things pop into my head that you could do:

 

1 - take your airbrush apart, completely, and throgouhly clean every part. Use dental brushes to get everywhere and remove all clogging

2 - lower your psi. I use ~15 as my standard setting. 40 is very high.

3 - shake very, very, very well then use Vallejo thinner in a roughly 80/20 mixture of paint/thinner for VMA. Try mixing before putting it into the cup.

 

Hope it works out for you

[JeffTibbetts]

 I've found Vallejo paints to be the ONLY ONES that do this for me. I may or may not have gotten a bad pot or two of primer, but it's basically the issue you're having. I've tried adjusting the PSI, of course, and used maybe a half-dozen different types of thinners (don't use Windex if you have an expensive brush, by the way. The ammonia can damage the rubber seals inside over time) including waters, alcohol, 'real' airbrush thinner and a mix of Liquitex mediums I use to cut most Citadel paints. Pretty much no matter what, I get clogs. Out of a dropper bottle, that really shouldn't happen. You may need to strain your paint, though. If you do, good luck because I've always found the process to be incredibly messy and wasteful. I wish I could tell you how to fix it, but I don't know myself. I contacted their customer service about it and they asked me a bunch of questions I already answered in my original post and weren't terribly helpful. 

[Dillithium]

I bought my first airbrush about a month ago, I've been doing a lot of experimenting on Macragge marines and just did my first full model! (drop pod)

Let me share some lessons I learned about Vallejo paints, I've been using vallejo game air and model air.

 

Mix in a seperate bowl. Not in the airbrush. It may just be me, but mixing it in a stainless steel petri dish works wonders for me compared to dumping it in the paint cup.

 

Primer I shoot at 35 PSI, the gray, black and white urethane primers. No thinners, straight in the airbrush. 0.4 Needle size.

 

Thinning Vallejo is honestly not enough, I seriously recommend ''Flow improver''. This is retarder for an airbrush. It seriously prevents tip dry and really improves the way paint hits the model. 

 

Now, every paint from vallejo other than the primer needs to be thinned. How much thinner and flow improver? This varies, but between thinner and flow improver I use about a 2:1 ratio. For 6 drops of thinner, I add 3 drops of flow improver. The problem is that thinning varies between colours. My yellows need a lot less thinning than my dark greens. Metallics need an insane amount of thinner compared to the normal colours. For 10 drops of chainmail silver, I use 10 drops of thinner and 5 flow improver. Well beyond 1:1 thinning. It's really about trying it out. Start conservatively, add more until you reach a milk- like consistency. What is a milk-like consistency? When you move it around, it leaves a slight thin trail of paint where it's been. Almost see through.

 

The most important part is to develop a good feeling for pressure and paint thickness. Is your paint thick? Increase the pressure. Watery? Lower the pressure.

 

Any layer paint I shoot between 20-25 PSI, with a 0.4 needle. If I switch to my 0.2, I even go as low as 10 PSI. Now, the lower your pressure is the more you need to thin your paint. 

 

About your setup:

 

Do you have a moisture trap?

What kind of compressor? With or without Tank?

What kind of airbrush? Needle size?

 

Most importantly with vallejo, are you shaking your paints before using them? I added glass agitators to the bottles, but even with that I need to shake much more than GW paint. Run the bottles between your hands as if you're making fire with a stick, and shake thoroughly up and down. This will help with opacity and paint flow.

 

Feel free to ask more questions, I'm sure I've forgotten something.

 

Happy airbrushing!