Mr. Chee, Concerning preheating, recommendations are to measure 107'C. in RSS side or 120'C in WSS side prior entrance in the wave solder pot. This is to minimize SMT WSS component crack due to "delta t" temperature gradient and to have flux activation without having pcb wet. In this conditions, you should have minimum residue formation. Concerning running non-stop wave solder, you should consider that stop function bewteen boards will reduce dross formation but increase concern in controlling wave heigth precision. So in my case I work with continous pumping and I do a periodical machine de-dross cleaning ______________________________ Reply Separator _________________________________ Subject: [TN] To On or Not to On -Reply Author: "TechNet E-Mail Forum." <[log in to unmask]>, at CCGATE Date: 16/2/98 8:20 Mr. Chee Please advice the tech. to present a rose to the prod. supervisor. It is not a good idea to argue with a lady in a work place. Men usually lose out at the end regardless of who wins. This doesn't mean she is right. Tell the tech. ( when you are alone with him) keep the preheat temp at 120'c and leave the sensor on (or increase the sensor on time to prevent some miss-outs) regards Matthew NII >>> Hew How Chee <[log in to unmask]> February 13, 1998 7:23 pm >>> Hello, Can anybody please help or advice. I am trying to settle a dispute between my company's production supervisor and the maintenance technician on the wave soldering machine. 1) The maintenance technician insisted that the wave should be switched on and off between boards to prevent/lessen "damage" to the wave creation mechanism. (The wave can be switched on and off automatically by a sensor on the conveyor). My production supervisor think otherwise. She covered the sensor so that the wave would not be off.(She says the sensor can miss a board) So, who is right ? 2) My production supervisor sets the preheat to about 95 degree C so that the flux would not dry up when the PCB board reaches the wave and to increase solderability.(but this created a lotof residue on the solder bath,according to maintenance). My maintenance technician says the temperature should be about 120 degree C so that it dry up the flux before the board reaches the wave. The reason is so that not much residue is created. Who is right again ?? Thanks in advance. How Chee Malaysia ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################ ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################ ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################