Thinning Tamiya Acrylics is SUPER simple: thin with 91% alcohol from the drugstore. (Ive been with MM Enamels since they first came out and now after all these years, and fighting with other acrylics, I find Tamiya by far the easiest to deal with).
I clean up the stuff in this order: Blow the rest of the paint out ( I dont mix much at a time to begin with, gravity feed Iwata) , run water through for a few seconds, then take a cheap big brush and wash out the cup with sudsy ammonia. Then flush ammonia through it for a few seconds.
Works every time been doing it this way for about twoyears now. I used some MM Acryl and the damned stuff turned rock hard in the airbrush and I spent the rest of the day chiseling that nastystuff out (thiined with thier own thinner)
Dont forget to use a airbrush lube like MediaLube, run a drop through the cup and blow it out, it works great next time when you are ready to go and there is no stickyness in the airbrush at all.
David
Build to please yourself, and don't worry about what others think!
TI 4019 Jolly Roger Squadron, 501st Legion