Airbrush - I must be doing something wrong

I'm not familiar with your setup, but it seems the paint is drying on the needle tip or in the nozzle, then when you pull it back wide open, it clears it out for a bit until it dries again. I would suggest thinning the paint even more. Maybe someone here who thins Tamiya with laquer thinner can chime in on their thinning ratios.

It does sound like tip dry - as suggested try thinning a bit more & if that doesn't completely solve the problem try an additive like Liquitex Slow-Dri or Tamiya Retarder.

Chromedome35,

I don't think you're doing anything wrong;  "It's just nature of the beast" when using acrylics. Try (do!) what Nathan and Milair have said -should help. I've been using Craft acrylics and have had the problem you describe - so, after getting the thinning/retarder/etc correct this is what I do. I keep a little cup of Windex and a Q-tip or Cotton Bud or whatever handy. I spray and, if I put the AB down or get tip dry, I dip the Q-tip in Windex, retract the AB needle, swab the nozzle and get on with it. YMMV but works for me.

I would start by ensuring that the airbrush has been thoroughly cleaned.

At the pressure you're using (15 PSI) I would suggest more thinner. Try two parts thinner to one part paint to start with. Mr Color Levelling Thiner already contains a retarder - that's the difference between it and regualr Mr Color Thinner.

Personally, I like to run Tamiya acrylics very thin and often use 80% thinner (4 parts thinner to one part paint). Most of Tamiya's paints (with the exception of the whites, yellows, reds and oranges) have quite a heavy pigment load and can be thinned extensively.

The metallics in the range can be a little tricky though, and you shouldn't thin them as much as the solid colours because the metallic pigments are quite heavy and will settle quickly if the paint is too thin, often clogging your airbrush.

Chromdome35

I'm having a problem with my Badger 105, bear with me as I try to describe this coherently.   

Frequently while I am using it, when I engage the trigger to get a light flow of paint, nothing comes out.  As I increase the pull back on the trigger nothing happens until BAM big splat of paint.  After that, it works fine for a bit delivering a fine misting.  If I stop for a minute, then I find I have to blow it open again.

I'm using Tamiya Acrylics thinned 50/50 with Mr. Color Leveling Thinner.  Regulator is set to 15 psi.

When it starts flowing, beyond the initial splat, it flows fine and paints wonderfully.

What am I doing wrong?

Did you push down on the trigger to get the air flow going before pulling it back? The Patriot 105 has a quick paint release type trigger action due to its bi-cone needle. Some user likes it, but others find it hard to get use to. (I am one of the latter.)

Try using water color to get used to the trigger action before doing actual painting. Using a 1:1 paint thinner ratio, the 15 psi is on the low side. You may want to try 20 psi or so and see if it makes any difference. You can also try to thin the paint more.

I use tamiya a lot but never with leveling thinner, i justvuse their own acylic thinner or isoproply alcohol,. Tip dying is something everyone has to deal with, but this gummimg up usually means not thinned enough or too low a pressure when i spray.

Acrylics need to be airbrushed at a pretty high psi.  I use 30psi for base coats and about 25psi for detail painting.  It sounds like your not using enough pressure and the paint isn't thinned out enough.  The only time I would say to spray that low would be if you were doing some post shading work with highly thinned paint or using solvent based paints.