How do I stop getting that gritty blowback when spraying deep cubbies?

The dry spray you're seeing in those cubbies is usually caused by too much air pressure creating turbulence that dries the paint mid-air before it can level out on the surface. When you're spraying into a confined box, that air has nowhere to go but right back at you, carrying half-dried particles that land on the neighboring walls you just finished. It's a common headache with HVLP setups if the CFM is cranked too high for the space. To fix this, you need to change your sequence and dial back your settings. I always hit the back corners and the back panel first, then work my way out toward the front edges. If you spray the sides first and then the back, the blowback from the back panel will ruin the sides every time. You also want to use the lowest pressure possible that still gives you a good fan pattern. If you're using a modern waterborne lacquer or paint, adding a **flow additive** or a bit of retarder helps alot. It keeps the paint "open" longer so that any overspray that lands actually melts into the finish instead of sitting on top like grit.

For units with that many individual cubbies, I’ve mostly moved away from spraying them fully assembled. It’s much easier to spray your sheets or your individual carcasses before the back panels are attached. If the back is off, the air just flows through the unit instead of swirling around. It saves you from having to do that awkward reach into the depths of a dark box while fighting the bounce-back.

And don't be afraid to thin your material a bit more than the bucket suggests, especially in warm weather. A thinner mix flows better into those corners and levels out before the air can mess with it. Just watch out for runs on the vertical surfaces. If you have to spray it after it’s already tied into the walls, keep a **tack cloth** handy and lightly wipe down the surrounding areas between coats once they’re dry to the touch to knock down that sandpaper feel before your final pass.

Have you ruled out the needle and nozzle size on your gun? Even if you dial the pressure back like the other guy said, if your tip is too large for the viscosity of the paint, you’re just throwing way more material into the air than that cubby can handle. I’ve found that even with the right sequence, a 1.8mm tip on a waterborne finish is just asking for a sand-paper texture in tight spots. Are you sure you're not just moving the gun too slowly becasue you’re worried about coverage? Sometimes that extra 'dwell time' in the corners is what’s acutally killing the finish.

Listen, if you aren't using a Graco FF LP tip, you're making life harder than it needs to be. I switched to the 210 or 310 Fine Finish Low Pressure tips on my Titan 440 and it’s a night and day difference for built-ins. You can drop your PSI significantly—down to about 800-1000—and still get a perfect atomization without that hurricane of bounce-back in the cubbies. Also, ditch the standard house paint. Grab some Milesi or Envirolak. Those Italian coatings lay down like glass and stay open just long enugh to melt in any dry fall. Are you using a swivel on your gun? It helps a ton with the ergonomics in those tight boxes.