> The saponifier chosen (not all > created equally) needs to be able to adequately remove the soils involved. > I agree with Doug. I've always likened saponification to peeling an onion down to the core, layer by layer. This was why the famous tests done by Jim Raby about 20 years ago came out so badly: his cleaning stage lasted only about 30 seconds and this was VERY insufficient to "peel off" all the layers of rosin (35% solids RMA flux). However, as Doug says, all saponifiers are not created equal but there are a number which are a little more equal than others. I've had very good results with Loncoterge 446 and Alpha 2110 (I think the numbers are right, but this is from memory) but both are very aggressive and require the most careful rinsing, care with amphoteric metals and check the surface attack of laminates, as well (some badly cured laminates have resulted in weave exposure). Of the slightly milder ones, the Vigon mentioned before is excellent. However, what Doug forgot is that "no-clean" fluxes are not created equal, either. Some are totally resistant to saponifiers, whereas others will clean off like a charm (plus all intermediate stages). In other words, the whole process requires qualification. My personal view is that "no-clean" fluxes are formulated to be plus or minus safe, **under specified conditions**, provided that the bare board and all the components have quasi-zero contamination up to the moment of fluxing. Cleaning them is therefore not in the design of them and is at your own risk and peril. Fluxes which are designed to be cleaned are usually formulated to ease this operation and leaving them on the board is at your own risk and peril. The window between the two where you can clean or not clean the same flux is very narrow. After all, a professional carpenter has his electric drill and his electric rotary saw as two separate machines: you wouldn't expect him to use a saw attachment on his drill, would you? Therefore, why should you expect the same flux to do two entirely different jobs? Brian --------------------------------------------------------------------------------- TechNet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF TECHNET Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------