HI Steve It's fairly simple to at least approximate what you've got to do to get an in spec alloy. It's just a matter of percentages. Assuming you do have a 1800 lb pot and 200 lb of lead free alloy, and the alloy is SAC305. . At 0.5% cu, 200 Lb of SAC will give you 1lb of copper. In a 1800 lb pot that will be 1/1800x100= 0.06% Cu . Same sums for tin and silver. . Then look at what you want to end up with.(0.63 x 1800 minus 186 of Sn you already have = add 948 lb Sn and 666 lb Pb. Fortuitously that's around 1600 pounds of 60/40. . You would need to pump the machine for several hours to get an homogenous mix and then re-analyse. Given that the 200 lb is an estimate it may be advisable to count the amount of alloy you are adding so you can redo the sums as you go/required, leaving room for a correction. Anyway you get the idea I hope. Regards Mike Fenner Bonding Services & Products M: +44 [0] 7810 526 317 T: +44 [0] 1865 522 663 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory Sent: Thursday, March 14, 2013 12:21 AM To: [log in to unmask] Subject: [TN] Extra Lead Free solder in wave solder pot... Hi all! My new employer has purchased a used Vitronics-Soltec 6622 wave solder machine that supposedly still has 100-200 lbs. of lead free solder in the pot because they were told that it was difficult to remove. My new employer is intending for this wave to be run as a leaded machine. So, what do you think about leaving that residual lead free solder in the pot and just filling it up with 63/37? I haven't seen the machine yet (I've yet to get to Boise), and I've never seen the inside of a empty -6622 wave solder pot, so I don't know why it would be difficult to empty the pot completely. I've always been able to get all of the solder out of all the pots that I have ever emptied. Does it have immersion heaters that are mounted in some sort of structure at the bottom of the pot that prevents all of the solder from being removed? I've been told that a sample of the solder that was left in the pot has been sent to AIM solder for analysis, so we'll know exactly what it is. I know that most lead free solders are mostly tin, so would it be just a matter of adding extra lead to the pot to bring everything into compliance? I definitely plan on getting the solder analyzed once the pot is filled and before any product is run, but I want to know if this is a bad idea? I don't want to load up the pot with solder and learn later that the pot is contaminated and has to be drained. Sorry for all the questions but I have never taken a wave that has been run as a lead-free machine and then be converted to a leaded machine...plus I'm not yet as familiar with the pot and heater configuration of the Soltec-6622 machine as I would like to be. If it was the other way around (leaded ----> Lead-free) I wouldn't even be thinking about it, NO WAY! Steve ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________