Lainie, Unless I am mistaken, Kester 1189 is or was, Hughes HF1189 which was essentially a mix of citric acid (lemon juice) and water. The "baked on flux" may be severe corrosion even an etched surface? Surely someone at Kester can advise you? Perhaps Bob Clarke who was at Hughes Tucson, is a TechNetter and could advise? It would seem that you are trying to clean up your wave solder machine so doesn't the supplier have an answer? My only suggestion, without knowing the thickness of the flux deposit, would be to try a "Stripping solvent" such as HumiSeal 1076 or even 1063. Call Bill Lott at HumiSeal: (718) 932 0800 Graham Naisbitt Concoat Ltd Email: [log in to unmask] Alasan House, Albany Park Tel: +44 (0)1276 691100 Camberley, Surrey GU15 2PL UK Fax: +44 (0)1276 691227 -----Original Message----- From: TechNet Mail Forum On Behalf Of Lainie Loveless Sent: Tuesday, August 12, 1997 4:40 PM To: [log in to unmask] Subject: [TECHNET] Cleaning Baked Flux Hi All --- Does anyone know of an effective way to remove baked on flux in general and in particular from pre-heaters (bulbs). Alcohol is not working very well and scraping is slow and tedious. Thanks! P.S. The flux is aqueous (Kester 1189). Lainie Loveless General Atronics Corp Wyndmoor, PA (215) 242-7336