The HVLP Replacment Cup from Rockler Woodworking and Hardware allows you to use and store the finish you use with your HVLP spray gun in the same container, eliminating the time-consuming step of transferring finish back and forth between container and sprayer. The cup is a graduated cylinder with metric and imperial scales up to 800 ml or 28 ounces, which attaches to your HVLP sprayer or can be used for storing your finish – or your solvent. (It comes with a cap, as well.) It sells for $7.99.
