Soldering tarnished terminals!
Posted: Tue Feb 27, 2018 2:14 pm
I just had the need to solder a 100+ Switchcraft A4M and A4F connectors. I got a great price on the large quantity I needed but it seems many of them may have been old new stock.
The contacts, which I assume are silver plated were tarnished and the soldering was not going well. I used a Kester activated flux and it went much better, but not great. Way too much heat to get the flow needed for a good connection was required. I ultimately tried Tarnex, with great success, only on the A4M connector since there are no hidden areas and washing afterwards would not be a problem. The A4F, with its' enclosed contacts are a different issue so I stayed with the conventional flux for those and drying it completely without a bake out may be difficult.
I am well acquainted with Deoxit and their great products but this is a soldering, not a contact issue. Since the contacts wipe when inserted the oxidation is not an problem on that side of the connector.
While on the subject of solderability, I also solder hundreds of small bipin lamps (#7373) to PCBs. These pins are a bear to solder since the pins are plated, I think with nickle, and no 'approved' flux seems to make it better. I recklessly resorted to using Stay-Clean liquid flux, which is a great metal soldering flux, and works like magic on those pins, but it is not recommended for electronics. Immediately after soldering the lamps I drop the assembly into a warm soap water mix then afterwards use a similar mix and ultrasonically clean them. At the end I use a conventional spray flux remover. I did a batch of those a year ago and so far there has been no evidence of corrosion due to the Sta-Clean.
I also considered using Stay-Clean on the A4 connectors, but because I am soldering stranded wire to the pins I am sure the flux would migrate into the connector and wire insulation to cause grief down the road. The lamp assemblies are more straight forward to clean afterwards than the connector.
Years ago I worked at an large local electronics distributor and we often dipped tarnished silver plated contacts into a puddle of something before shipping. Was it Tarnex? Well maybe, but unfortunately I have no idea what was actually used.
I would appreciate any comments or ideas, or tales of soldering success.
The contacts, which I assume are silver plated were tarnished and the soldering was not going well. I used a Kester activated flux and it went much better, but not great. Way too much heat to get the flow needed for a good connection was required. I ultimately tried Tarnex, with great success, only on the A4M connector since there are no hidden areas and washing afterwards would not be a problem. The A4F, with its' enclosed contacts are a different issue so I stayed with the conventional flux for those and drying it completely without a bake out may be difficult.
I am well acquainted with Deoxit and their great products but this is a soldering, not a contact issue. Since the contacts wipe when inserted the oxidation is not an problem on that side of the connector.
While on the subject of solderability, I also solder hundreds of small bipin lamps (#7373) to PCBs. These pins are a bear to solder since the pins are plated, I think with nickle, and no 'approved' flux seems to make it better. I recklessly resorted to using Stay-Clean liquid flux, which is a great metal soldering flux, and works like magic on those pins, but it is not recommended for electronics. Immediately after soldering the lamps I drop the assembly into a warm soap water mix then afterwards use a similar mix and ultrasonically clean them. At the end I use a conventional spray flux remover. I did a batch of those a year ago and so far there has been no evidence of corrosion due to the Sta-Clean.
I also considered using Stay-Clean on the A4 connectors, but because I am soldering stranded wire to the pins I am sure the flux would migrate into the connector and wire insulation to cause grief down the road. The lamp assemblies are more straight forward to clean afterwards than the connector.
Years ago I worked at an large local electronics distributor and we often dipped tarnished silver plated contacts into a puddle of something before shipping. Was it Tarnex? Well maybe, but unfortunately I have no idea what was actually used.
I would appreciate any comments or ideas, or tales of soldering success.