I have been using an ultrasonic cleaner for over a year now, the tank is 300mm x 250mm x 200mm deep and find it ideal for cleaning up engine parts and clocks, it works very well on dirty stubborn old oil and grease, even if you only use a good household detergent in the water you can get good results, with the chemical cleaner I use it will clean a full long-case movement in less than 15 minutes, and it come out bright but it will not touch rust. I once tried a small unit but I think it was better suited to just jewellery, not scale engine parts and clocks. Phill Clayton No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: 269.16.3/1144 - Release Date: 21/11/2007 16:28 MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.