Acrylic paints thicken once open?

[Vic]

A newbie question likely - I am using Tamiya acrylic paint on a 1/350 Ticonderoga CGN. I find that my first applications of paint to it are fairly smooth with no noticeable brush strokes, but after a few weeks ( I work on the model on and off ), when I go to paint another part, the brush strokes become more and more obvious. It seems to me as if the paint is thickening in the bottle.

Does it really do this, and if so, should I be applying a small bit of paint thinner to an already opened bottle before using it again?

[Devin]

Any paint, over time after opened, will begin to set-up and get thicker. This is more prevalent with acrylics as they dry quicker. Since you're already experiencing the problem, then thinning is the best way to combat the problem. I'd suggest not putting thinner into the bottle of paint, though, use an eye dropper to put the paint in another cup or some other item and then thin that small amount.

The best solution is to obviously stop the paint from getting air into it and starting to set-up/thicken in the first place. After you open a bottle of paint, store it UPSIDE DOWN. That will keep the seams of the lid sealed air-tight with the bottle. If you don't want to do that, be sure to wipe the lid and bottle threads clean before closing the bottle up for storage.

-Devin

[Vic]

Thanks!