There a few reasons for this. The fluid nozzle and or air cap may be loose, causing it to bubble. The fluid nozzle may also be dirty and clogged with dried paint particles. Lastly, there may be a crack in the fluid nozzle which you will need to replace. Also make sure to thoroughly clean the needle. Any dried paint on there will assist in not spraying.
When I Try to Spray My Airbrush, I Get Bubbles Back Into Paint and No Paint Comes Out, Why?
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