Never used one but had my bathtub refinished and that is what they used. Of course they were spaying some heavy specialty paint, not clear. The finish on the tub has the most peal in it I have ever seen
In fact they had to redo the the job cause the guy must have run out of paint or was rushing and didn't get full coverage.
Not sure if this is indicative of the units or just a bad painter, but I wasn't impressed and they are big bucks!