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This is really a question aimed at the guys with a fair amount of experience with an airbrush.

i have a H&S Evolution Silverline 2 in 1 and i am running GW paint through it, i thin to what i think is a good consistency in that it covers well in a few passes but holds doesn't clog the brush when using the .4 nozzle when running at about 15-20psi. i always strain the paint to avoid clogging and i always clean the AB between uses.

So my question here is when i use the 0.2 nozzle i am getting serious blockages, if i thin the paint it does not hold well and will start spidering if i lower the amount of pant flow it clogs, if i raise the PSI i get spidering.

Is this an issue with the paint, or is this an issue with my technique? if this is a technique issue any tips would be much appreciated as i am looking to improve my airbrush use.

i would love to get thinner lines etc, but at the moment i can get thinner more consistent work with the .4 nozzle.

I would guess that it is a combination between thinning, pressure, and distance from the model. I find the thinner your paints, the lower the air pressure, and the farther back you have to hold the airbrush from the model. It takes a great deal of patience and experimenting to find the combination that works for you. Drop the air pressure, and move the brush back from the model and see if you still get spidering.

I asked a very similar question over on the PP boards a while back. Plarzoid (who is a mod over there) explained it in terms that made sense to me. I hope this helps a bit.


"PSI is force divided by area. In Air pressure, this is essentially how many times and with what speed the air molecules are moving at when the impact the surface. (Technically force, but speed has a better visual for our purposes).

So, our rough equation is: PSI = (# molecules) * (speed of molecules) / (surface area)

In your case, you've reduced the surface area (nozzle size) and kept the PSI constant (I assume). However, with less surface area, you also reduce the number air molecules that can fit onto the measurement surface which effectively reduces the (# molecules) variable. As a result, for the math to work out, the (speed of molecules) variables has to increase.

So, your 20-25 PSI and 0.2 nozzle is actually forcing out the air faster (with more force per molecule) than the exact same settings with a 0.3 nozzle, which is why you're getting the spider-webbing."

If you are using a hobby-quality paint (Minitaire, GW, Vallejo, Reaper, P3, etc.), you shouldn't have to strain it - these paints are very good quality compared to craft paints you might get at Wal-Mart or a crafts store.

From the info you give, I think your issue is mostly thinning the paint properly - it should be the consistency of skim milk. Thinned properly, it should take several passes before you get a complete base coat on your models. And since you'll be spray less it won't take very long to dry so for example if you're painting a 10-man squad of marines, by the time you get to the last man you should be able to put the next layer on the first man. Same thing with a Rhino or whatever - start at the front, work around the side, back, other side, bottom and top, and the front should be nearly dry enough to spray again.

Once you have thinned the paint enough, you can spray at a lower psi, closer to the model. If you have to, get a piece of scrap plastic (not paper, because the paint will absorb in and act different) and write at the top: 5psi on one sheet, 10psi on another, 15pis, 20psi. The write on the left side going down: 1" (or 2.5cm, whichever), 2", 3", etc. down to 8" or so and spray each piece of plastic in a smooth motion at the distances specified so you can see what effect the distance and psi have with *properly thinned paint* (very important! you need a constant for this experiment to work). Then you can refer to these pieces of plastic when you need to.

tbh, I don't think that figuring out the math of air molecules will be very helpful just practice, and experiment with what you can: air pressure, paint viscosity (thinning) and distance from the painting surface.

 krushgroove wrote:
If you are using a hobby-quality paint (Minitaire, GW, Vallejo, Reaper, P3, etc.), you shouldn't have to strain it - these paints are very good quality compared to craft paints you might get at Wal-Mart or a crafts store.

The potential necessity of straining has more to do with storage and dispensation methods than with the perceived quality of the paint. Doesn't matter how finely ground the pigment is when it comes to crust forming at the dropper nozzle/pot lip (far more likely with a pot lip, I'd say), breaking off, and mixing in with the paint. I have more of an issue with chunks in my GW paints, due to the container design, than I do with my flip-top bottles of craft paint and I'm far more careful with the former.

I'm not too experienced with the airbrush but I can't stress enough on correct thinners. Tamiya thinner with vallejo paint doesn't work at all, the pigment separates, same with gw. You'll need to experiment with each thinner and each paint, only comes with experience. What works for me and the others will most likely not alway work for you. I use the same psi and the same paint consistency as I do with a .4 nozzle as with a .2, disregard the formula as unfortunately we don't live in a bubble.

I too use the Silverline and its very, very picky with the .2 needle. I use a variety of paints and even thinned to the same consistency and using the same psi, the performance is different.

I have gotten better with trigger control and now only use the larger needle as I can get in and do fine stuff too. Little to no clogs and more time spent painting rather than trying to clean the brush.

Excellent info in this thread.

I can chime in as well that when using my sotar or krome (.2 needles) they are indeed very picky about paint as well.

I try to only use dedicated airbrush paint in them (golden, vallejo model air, or minitaire - I don't care for createx).

Where as my patriot 105 or my hpcs are usually ok with almost anything I put in them, given proper thinning (real ab thinner is worth every single penny) and I have either avoided or filtered out any dry paint chunkies.

I would say that about ...90% of the time that I am using thinned non-ab paint (vallejo game color, gw, old gw, p3 what ever) in my lager needle brushes, they are ok.
Once I go to my small needle brushes....yeah, I try to only use AB paint, or have to deal with ....very picky tools.

best of luck!

Thanks for the great info guys.

Ill give all of these a go and i will get some AB paint to see what will work.