Donnn, Donnn, To add my experience of working with OSP (Entek Plus 106A), you never get 100% hole-fill with wavesoldering process. You get a better result with Organic flux (Water-soluble flux) since they are more active. I suggest you contact Enthone, Kester, Alpha-metal and/or other flux mfg. Most flux mfg's have no-clean flux formulated especially for OSP coated boards. OSP formulated no-clean flux is more active and give a better result filling holes. Since you are working with IPC Class 3, it is more hassle with unfilled hole, I am happy with 75% hole fill. regards Matthew Park NII-Norsat International Inc. ################################################################ 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################