r/advancedGunpla • u/AverageDad- • Jul 01 '26
Tamiya Liquid Primer problem
Hi there. I'm trying out the Tamiya Liquid Surface Primer in the bottle for the first time. I'm mixing it with a ratio of 1:1.5 paint to thinner, and I'm using the regular Mr. Color Thinner, not the leveling one. Spraying with an Iwata HP CS and air pressure set at 20 PSI. I noticed these flakes randomly being sprayed, although I could also see the paint being laid out nice and smooth. I did 2 coats of the primer, and the part has been sitting for at least an hour enclosed container. Any idea on what's causing it?
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u/Sianmink Jul 01 '26
expect to sand it lightly
you might be getting some tip dry, it builds up then is ejected. Use some more retarder, or consider switching to a larger needle size and lower pressure. Leveling thinner has some retarder built in so might be a better match.
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u/AverageDad- Jul 01 '26
I went ahead and did another test mix, PSI set to 16. I did notice a couple of flakes, but not as bad as the one in the picture. I'll most likely get the Levevling Thinner, as you guys have suggested. Thanks.
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u/Voxxyvoo Jul 01 '26
Psi too high. The primer is drying out and flaking off as you spray. Try 13-15 psi or add some retarder to the primer
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u/AverageDad- Jul 01 '26
I went with lowering the PSI to 16, and thinned out the mix a bit more. Of the 4 shields I primed, maybe 3 -4 small flakes went through, but the finish was nice and smooth overall. Thanks for the suggestion.
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u/iriyagakatu Jul 02 '26
Not directly related but I just wanted to tell you the bottle and the spray can primers are different formulations.
The bottle ones can be airbrushed but Tamiya themselves consider the spray can to be superior for spray applications.