Michael, QUESTION: at "normal" soldering iron temperatures, what happens when you melt a eutectic solder preform (p/o clip lead) together with hi-temp, 90 to 94% Sn (bal=Pb) solder? Will the two solders alloy, or just form a mixture? Please provide as metallurgically correct an answer as possible. Generally speaking, they will alloy. Issues that may impact the result are things like: melt (mixing) time thermal (convection) gradients flux activity presence of oxides presence of copper (intermetallics) from previous reflow cycles Andy Magee Flex Guru - Consulting [log in to unmask] (937) 435-3629 M.S.—Metallurgy—3.3 GPA—Univ. of Connecticut—1988 B.S.—Mechanical Engineering/Materials Engineering Dual Degree Cum Laude—3.3 G.P.A—Univ. of Connecticut—1979 AESF, ASM, MRS, ASME ################################################################ 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 ################################################################