Howdy 
, David, does that naptha leave a oily film??? Jim, I bought a new ultrasonic when I started, from prosonix. NOT a expert at these as this is the only kind I have owned, it seems to do a pretty good job and new it was quite a bit cheaper than most other models, 2 1/2 gallon, with 5, 55Khz transducers and heater under $400. William
