Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Soldering ideas

  1. Aug 11, 2011 #1
    Right now I am using silver solder to combine heating elements on a copper pipe. This is becoming very expensive. Any other means/materials I could use that could get the similar results as the silver without the high cost!
  2. jcsd
  3. Aug 29, 2011 #2
    Silver solder resists higher temperatures. If you don't need them, just take tin-copper solder used for electronics presently, or the better tin-lead that was used previously (forbidden in Europe now). Their melting point is like +200°C and +180°C. Clean surfaces and good flux are important.

    Available from plumbers and their shops.

    Other compositions exist(ed) which I haven't used, like cadmium. Must be forbidden in Europe meanwhile.

    At maximum +150°C, you can make a mechanical contact, with thermal paste between the parts. Press seriously with screws the precisely matched surfaces.
  4. Aug 29, 2011 #3
    As a plumber, we use standard 95/5 plumbing solder (available at home centers and plumbing supply houses). It is used on water and heating copper with pressures below 125 PSI and temps below 210 deg F.

    For pressures and temps above those levels we use Silver Solder. And yes Silver Solder is expensive. I do HVAC work and it is the only approved joining material for R-410a refrigerant due to the high pressures.
  5. Aug 29, 2011 #4
    Thanks for the replies. The fin heaters we use get pretty hot with the amount of 1 to 6 Kw supplied quickly passing 212F+. I'll keep at it I guess. Lead is good but needed major protection so I am sure it will not be the best bet.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook