tamiya Paint problem - Tamiya acrylic gloss mix sprays as satin

[chepp]

I'm starting to use mixes of Tamiya acrylic paint for airbrushing. What went wrong here?

The surface: styrene spoon wetsanded with 400 then sprayed with white Tamiya Fine Surface Primer (L).
The mix: Tamiya water clean-up acrylic in bottles
  1 part X-13 (medium-dark metallic blue)
  3 parts X-11 (chrome silver)
  1 part X-22 (clear gloss)
  X-20A thinner (eyeball ratio to dilute for airbrushing)
The spray: Iwata Eclipse at 20 psi

For comparison, there is a spoon test of gloss black at the left of the photo shot under the same conditions. It's Model Master 1747 diluted with Testors Airbrush Thinner.

The Tamiya makes a nice satin finish but I want it to be 1961-era glossy on an engine and frame. I could clear coat it but I'd rather figure out how to make the mix glossy.

[Matt T.]

I have the same airbrush. Try 25-30psi and opening the trigger more to get more paint/a wetter coat. I had to do this last week to paint my Hemi with a Tamiya acrylic orange mix. Hope this helps. 

[chepp]

Thanks, Matt. Your suggestions were good and helped a little. It may have been the chrome silver that caused the dulling.

Here are two more spoon tests with the following changes:
 1) pour off some of the thinner (it's separated in the bottle), 2) up the airbrush pressure to 30 psi and 3) spray several heavier coats letting each flash dry between.


The top one is just the airbrushed Tamiya mix over Tamiya White (L) primer.
The bottom one is the same plus two heavy coats (about 40 min. apart) of Tamiya TS-13 from a spray can. That gloss looks OK for the engine and frame I'm planning to use it on.
I'll pay more attention to cleanliness when painting the model parts.
 

[Michael jones]

Id say your paint is drying too fast (even in mid air). Some people say Mr Levelling Thinner works with acrylic as well as lacquers (in which it is brilliant for slowing the drying process). I personally have only used Mr Levelling thinner with lacquers. It would be worth a try. Another option would be to spray during a cooler period of the day, or maybe spray closer. This can be hard to get right with acrylics as they tend to run easy.

[chepp]

Thanks, Michael. That sounds reasonable. All the spoons were sprayed at about 65 degrees F in the shade of a garage with the door open. I don't know what the humidity was — maybe 50%. I was probably being too careful to avoid runs. Although I don't have Mr. Leveling thinner, I do have some Golden brand retarder that is made for increasing the working time of acrylic paints. I'll try that before looking for Mr. Leveling.

[peteski]

I'm puzzled by the way the color shows some fine texture pattern. It almost looks like hammered-metal paint. It is almost like the various paints don't want to be mixed together and they stay separate, creating areas of silver dots with blue halos. At least how I see it on the glossier spoon in the last photo.

[droogie]

I've had problems mixing the metallic Tamiya acrylic paints with their solid color paints. I always get the same grainy/pixilated appearance.

[Snake45]

I'm puzzled by the way the color shows some fine texture pattern. It almost looks like hammered-metal paint. It is almost like the various paints don't want to be mixed together and they stay separate, creating areas of silver dots with blue halos. At least how I see it on the glossier spoon in the last photo.

That was exactly my impression, too.

[aurfalien]

Hi,

Well, by no means an expert but I'm seeing the benfits and wisdom of thinning Tamiya acrylics with lacquer.

I've also noticed better mixing of Tamiya acrylics when using lacquer vs alcohol as a thinner.

 

[chepp]

Thanks all, for the comments. I tried it again today with retarder added (halfway between the recommended high and low ratios). I sprayed both the airbrushed acrylic and later the TS-13 clear gloss much heavier than I would normally do but there was no improvement. So, I'll conclude that the problem is with the X-11 chrome silver. The chrome silver starts settling out within an hour of stirring it up so I guess that it just doesn't want to mix with the X-13 blue. I like airbrushing Tamiya acrylics but I won't spend any more time on this mix.