I've just started using an airbrush to paint my models. My current airbrush is a dual-action Neoeco SJ83 but I find it difficult to use because of arthritis issues with my thumb. I've ordered a Gaahleri GHAD-68 which has a pistol grip as a replacement. I am using Tamiya acrylic paints, thinning with Tamiya lacquer thinner. My question is, how long can paint stay in the cup before it clogs up the nozzle? As a newbie, I'm still making mistakes that require remediation before a subsequent coat can be applied. If I anticipate a lengthy interval before the model is ready for the next coat, should I clean the airbrush as though I were changing colors? If so, what would be a reasonable time limit? Thanks.