Tamiya paint pebbling?

What do you use as a thinner?

It's probably your thinner. If you're using a homebrew you probably don't have enough paint retardant in your mix to keep the paint wet long enough. Paint retarder is also good to help the paint level once its on the model. Personally I've done away with homebrew and just use X20A and it works well enough that I don't have pebbling issues or have the paint bloch up when I make a mistake. 

There are so many variables involved in spraying, you named some of them. Other issues are tip/needle size, air temp and thinner type. I use Tamiya also, exclusively X-20A, rarely a retarder. I often thin the heck out of it, maybe 50-70% thinner. I think 1-2 inches away, average pressure of 12-16psi. 

Just my best guess, maybe you're staying a bit too far from the surface, and perhaps the pressure is a bit too high. If you find time, please let us know what you determine, I'd sure be interested. Thanks for the post.

Patrick 

I would suggest using Tamiya laquer thinners and not X-20A, it has a far better ability to "melt" the base paint particles and provide a superior finish. I use about a 60:40 mix paint to thinner, but as a general rule the constency of skim milk. Your pressure is about correct, but as already suggested try shooting a little closer to your subject.

Test it out on a paint mule and see for yourself.

Best of luck.

I had the same thing happen with my XF-60 . I was spraying a 50:50 mix thinned with Tamiya lacquer thinner at 15 psi about 2-3 inches away. Maybe a problem with that colour?

I always use Tamiya X20A thinner when spraying Tamiya acrylic.

I also have a syphon feed badger 200 NH which will require more pressure as a rule,  than a gravity fed airbrush.

my XF 60 dark yellow is almost cut in half with Tamiya flat white to achieve accurate dunkelgelb. So it's not the color. It also happened to lightened Tamiya hull red.

I need the paint to go on wetter, whatever that takes.

I always use X-20A thinner with Tamiya acrylic, and have never had a problem with that.

Wilbur, you may have already tried this, if you slow down your paint passes and are close enough, you'll have a wetter paint mix laying down. You can actually get by with quite a lot of that, and not have the risk of runs.

While I rarely use them, products that affect the consistency of sprayed paint can be a help in some cases. Liquitex makes two, Flo Aid and Slow Dri, both can be rather touchy to use. Flo Aid is to be mixed 20:1 with water then added to acrylic paint, and their instructions say use sparingly. They are not kidding, but it has it's place when needed.

Slo Dri is a different matter, it is added as a surfactant to simply slow the drying process, I think maybe better for using a paint brush. Must allow two or three days drying time before further work, like decals or clear coat. I have airbrushed with it but didn't seem useful to me.

The 200NH has a fairly generous needle/nozzle size, so it should be capable of laying down a wet mix. I use about 15psi with mine. Hope you get it sorted.

Patrick

Tamiya has a retarder. Just got it but haven't used it yet though.

I know a number of folks who say to thin to viscosity of some form of milk, say 2%, or skim, or whatever.  I don't really believe folks can consistantly judge the viscosity of milks that well.  I personally measure- you don't need to be super accurate on percentage, but I believe you can judge mixture ratios more accurately than viscosity.  Also, I hate the quick drying of acrylics, so generally I use retarder.

But I still prefer enamels just because I like the slow dry time, especially for gloss finishes.

I have the Tamiya paint retarder however did not use it this time, maybe I should have.

Don I always measure using one of those AK plastic pipettes so I can write down my formulas.

I always prefer enamels for aircraft and cars, however some time you just have to use the Tamiya to get the color right. Acrylic are so much easier to clean up and deal with when airbrushing, however one must deal with the problem which this thread is about.

As Patrick said, maybe my passes were too fast.  The model in question is the Takom Maus V1.

Funny thing, when I painted my big PBY with Tamiya Field Blue none of this happened.  I may have used the retarder for that I would have to check my notes.