Hi Daniel, Flux selection should be primarily a function of board design. Generally speaking, thinner fluxes tend to give better coverage with better rinsing. Thicker back panels need longer immersion times so they require a little bit higher viscosity product. Most products today have a hydrobromic acid activation package rather than HCl. This helps with the life of the equipment as well better ionics. Typically your vendor will be able to give you one flux to fit all your applications. We sell nearly 20 different vertical fluxes but two products make up nearly 75% of our sales. I will be more than glad to speak to you off line if you need additional information. Regards, Chris McGary Dexter / Alpha ############################################################## TechNet Mail List 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://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################