Do I need to thin paint for an HVLP sprayer?

Do you need to thin paint for an HVLP sprayer depends on paint type and viscosity, but generally yes, most paints need thinning for HVLP to atomize properly and avoid orange peel and clogging, unlike airless sprayers that can spray unthinned latex. HVLP spray guns operate at low pressure around 10 PSI at air cap and need paint viscosity around 20 to 30 seconds measured in DIN 4 viscosity cup for proper atomization. Thick latex house paint is too thick for HVLP and would need significant thinning 20 to 30 percent with water, which reduces coverage and is not recommended, so HVLP is not ideal for thick house paint, use airless instead. For automotive basecoat, clearcoat, and single-stage urethanes, you need to thin according to manufacturer mixing ratio, typically 1 to 1 or 4 to 1 with reducer, plus hardener, so thinning is part of normal mixing, not extra. For oil-based enamels, alkyds, lacquers, and varnishes for furniture and cabinets, you typically need to thin 10 to 20 percent with appropriate thinner like mineral spirits or lacquer thinner to achieve sprayable viscosity. Water-based acrylic enamels for trim often need 10 percent water. Always test viscosity and spray pattern on cardboard. So yes, for most paints you need to thin for HVLP, except pre-thinned automotive paints mixed per instructions.