Hi Nicolas, Here we make a lot of very small batches (sometimes only 1 or 2 boards) and I wouldn't like the idea of throwing about 400 grams of solder paste away after printing 10 grams onto the boards. We don't see a difference in soldering quality between products that we made with a freh jar of solder-paste and products that were made with paste that had been on the screen before. But most of our inspection is done after cleaning, so we won't notice an occasional solderball due to absorbed moisture. In a no-clean environment this could be different.... Kind regards, Daan Terstegge Unclassified mail Personal Website: http://www.smtinfo.net >>> "Stephen R. Gregory" <[log in to unmask]> 02/16 4:22 am >>> In a message dated 2/15/2001 8:46:23 PM Central Standard Time, [log in to unmask] writes: << Solder paste reuse: does anybody has this practice? Obviously, my solder paste supplier does not recommend it. Nicolas Ortiz Process Engineering Group Leader Conexant Systems >> Hi Nicolas, Your supplier is not recommending it to in order to sell you more paste, it is a valid recommendation. I'm not quite sure about what you mean by "reuse", but if you mean taking paste off a stencil, putting it back in a jar after a run, and then keep using it, that's a bad idea. The paste will absorb moisture, the volatiles in the paste will evaporate, basically changing everything about the formulation of the paste = not performing like it's been advertised to do...I don't know of any manufacturer of solder pastes that would recommend to reuse solder paste after it's been dispensed on a stencil... I do however, understand your concern about the expense when throwing away solder paste...it's not cheap, anywhere from $50.00-75.00 for a 700-gram jar. But you can recover some of the costs through recycling...Alpha/Fry Metals will recycle solder paste and give you back the money that the tin/lead market prices are at the time you turn it in... Bottom-line, don't "reuse" your solder paste...it'll bite you... -Steve Gregory- --------------------------------------------------------------------------------- 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 To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives 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 --------------------------------------------------------------------------------- --------------------------------------------------------------------------------- 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 To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives 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 ---------------------------------------------------------------------------------