April 2, 2012 The problem may not have anything to do with the solder used. The pipe could have some water remaining in it or a valve upstream of where you are soldering could have small leak. Any amount of water leak can make it difficult if not impossible to make a solder joint. Old plumbers trick by putting small piece of bread into the pipe may stop the leak long enough to make the solder joint. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman Sent: Thursday, March 29, 2012 4:57 PM To: [log in to unmask] Subject: Re: [TN] NTC- unmeltable solder Hi Blair - one other possible reason but lower on the possibility scale is that the solder joint, if old enough, had converted itself into a tin/copper joint rather than copper and solder joint. Most solders contain a low melting element - i.e. lead, bismuth, etc. - so the solder joints should go molten but if you had a high tin alloy with minimal lower melting point element addition, you would be trying to "melt" copper/tin intermetallic which isn't going to happen. Mike's or Chuck's responses are more probable explanations for what you experienced. Dave Blair Hogg <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 03/29/2012 12:20 PM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to Blair Hogg <[log in to unmask]> To <[log in to unmask]> cc Subject [TN] NTC- unmeltable solder The recent discussions on rework issues reminded me of a while back where I needed to repair a leaky water pipe in my home. Took a chunk of the ceiling out, got out the plumbers torch, drained the pipes and started to heat. No matter what I did to the joint that was leaking I could not get anything to melt. Had to cut the pipe on either side of the elbow joint and patch in a new section. Even afer I took it out I could not get it apart. Not sure what happened to the solder but something changed it to make it unmeltable. Blair ______________________________________________________________________ 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] ______________________________________________________________________