Fast Tracks

I finally got around to doing a test using silver bearing solder, .015", Radio Shack brand, rosin core. Up to this point I have used nothing but acid core on trackwork. I used acid paste flux with the silver bearing solder. The flux did not seem to be a problem.

The results: The silver bearing solder flowed much quicker than the acid core of the same diameter. Probably has a lower melting point. Although the joint seemed strong enough it was much easier to separate the PCB tie from the rail than it was with acid core. When separated with force the solder stayed primarily on the PCB tie, very little on the rail base. Separating the acid core joint sometimes resulted in pulling the copper foil off the tie and always left a good amount on the rail bottom. Both resistance and iron techniques were used. 35 watt iron w/ST7 tip, resistance unit w/tweezers, set to about 100 watts. I allowed more than enough heat and time on some joints, others were done in a "normal" amount of time, if there is such a thing.

Conclusion: The silver bearing solder will probably do an acceptable job when used with acid paste flux. It flows very good. Washing with soap and water is a must, baking soda can be used for further insurance that you get all the acid off but it will turn the shiny solder to a grey.

Other users may have different opinions about this. I do not know if there is a difference in the actual metal strength in various solder types.
I will not be using silver bearing solder for trackwork fabrication, however I will use it for wiring connections (without acid paste flux).

Sorry, I do not have photos of this to post (no digital camera yet).

I made the above post without realizing I was not logged in yet.

I have pulled off copper foil using the tix and silver bearing solder. First off the only difference between the acid and rosin is the acid. If you clean the copper to its brightest, (I use a wire brush in a moto tool) you should get the same results with both methods. Just be sure that the rail and copper is cleaned. Most nickel silver rail I've seen needs cleaning. They are grayish and if you use the same wire brush on the rail bottom your solder joints will have the same strength.

Rob

I am going to give it another test. I always shine up the PCB ties with a file, this helps to remove the burrs caused by cutting as well as gives a real shine and some striation lines, also I never clean the ties until I am fully ready to start assembly. Once I start soldering an assembly I complete it within an hour or less. I clean the rail bottom with a "Scotch Brite" pad until it has a buffed look. I will try to clean the rail even more, mabey use alcohol for the test. I would not use alcohol as a permanent solution for the process, though. Whatever the results, I will be sure to post them! I really like the way the silver bearing solder seemed to flow compared to the acid core. Do you know if it actually has a lower melting point or is it just my inagination?

Thanks for the reply.

The method I use for cleaning ties and rails is to lay a piece of 600 grit wet and dry paper on a piece of glass. A few easy swipes of the tie or rail over the paper just before they go into the jig seems to be all that is required for a tight solder job. Roy

Just another note on soldering rail to PCB ties....I use the Fast Tracks .015 solder, and I use Kester self cleaning paste flux Formula SP-50, which I brush onto each tie just before I lay the rail in place. This flux is a soft paste that sqishes out from under the rail when the rail is put in place. When heat and solder are applied at the same time....presto, a finished solder joint. Roy