No announcement yet.

copper buss bars plated with what?

  • Filter
  • Time
  • Show
Clear All
new posts

  • copper buss bars plated with what?

    Got some copper flat bar today, some is 2 inch wide, some 3 inch wide, and 1/4 inch thick. There's a sign on one that says main bonding jumper. I was told that these are silver plated, and it does look like it. Definitely not galvanized or painted. Where the bars have been sheared there's a smear of silver or whatever it is about halfway through the thickness of the material- same for where the holes have been punched.

    Is this likely to actually be silver?

    And of course the inevitable question- what can I use this for? Heavy duty switch contacts is one use, specialty soldering and desoldering tips is another. Anti-bacterial inserts for water bottles?
    I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

  • #2
    If it is Silver plated Bus,then it will only be flash plated 8-10 microns thick,just as an anti-corrosion layer IIRC,not much good for contacts.

    On the other hand,if it is Silver,then some nitric acid and table salt may come in handy.
    I just need one more tool,just one!


    • #3
      Busway is greek to me. GE has some nice technical literature that may help with understanding how connections are made, refreshed, etc.


      • #4
        McMaster has silver-plated copper, mostly used for bus bars to maintain conductivity of connections. Copper forms copper sulfide, a green patina which is non-conductive, or copper oxide, also non-conductive. A thin layer of silver plating prevents this, and instead forms relatively conductive black silver sulfide (or oxide).
        Paul , P S Technology, Inc. and MrTibbs
        USA Maryland 21030


        • #5
          How much did you get ? Are you selling any ?
          Trying to think of a cool use for it.


          • #6
            Hey Darrel,

            From my experience (electrician) the plating is aluminium not silver. The manufacturers do coat the copper to prevent oxidation which is a insulator for electricity. The reason the cut looks the way it does is the aluminium was deposited before final assembly and it was sheared just as you surmised. The copper is of a grade "A" so you do have some good material to work with. I tried once to machine a piece and it did not go very well, I hope you have better luck. I have a couple of pieces on my welding table for backing and other use since welding around it does not stick.
            Let us know what you end up doing with this new treasure.


            Well I was wrong, here is a link to some information from a major manufacturer of electrical equipment.

            Mr fixit for the family
            Last edited by Mr Fixit; 05-28-2017, 01:42 AM. Reason: correct my error.


            • #7
              I've installed many buss bars (1/2" x 6" and 1/2 x 8" for electric furnaces for Union Carbide and Norton Abrasives. Every joint was silver plated to prevent oxidation.


              • #8
                Can be silver or tin. Both have conductive oxides, plate well, and fix the surface corrosion issue. A lot of aluminum lugs are tin plated.
                4357 2773 5647 3671 3645 0087 1276

                CNC machines only go through the motions

                "There's no pleasing these serpents"......Lewis Carroll


                • #9
                  Besides silver and tin, nickel is also used on copper bus.
                  12" x 35" Logan 2557V lathe
                  Index "Super 55" mill
                  18" Vectrax vertical bandsaw
                  7" x 10" Vectrax mitering bandsaw
                  24" State disc sander


                  • #10
                    I work in the communications field. We use a lot of these at tower sites for lightning mitigation.
                    Back when copper was very expensive there were a ton of thefts of these at tower sites.
                    Other base / core materials were used at that time to reduce cost and to take weight off the bars making them worth less at the scrap dealer in hopes they would stay in place. Older bars were high grade copper and were both expensive to buy and valuable as scrap due to being number 1 pure copper. Various core materials were used with what would be considered thick copper plating to maintain conductivity for lightning mitigation. I know that aluminum was never used as it was never allowed in any lightning mitigation per the R-56 installation standard that was created by Motorola (now Motorola Solutions).

                    My guess is that it's Zinc core,,, as many were.


                    • #11
                      Wrap a rubber band around one of the bars, wrap it in saran wrap or something to restrict air movement , and put it aside. If the plating is silver, black or purple stain should develop where the rubber is in contact. Keeping rubber bands or other rubber in the silver drawer will do the same to silver plated knives, forks and spoons. I think it's caused by sulphur compounds in the rubber.

                      A company I did work for silver-plated all their buss bars with a rub-on paste. It was obviously a very thin plating, and I have no idea how effective or durable it was.
                      Last edited by cameron; 05-27-2017, 11:58 PM.


                      • #12
                        It took a while, but I found a copy of the R-56 standard, and it does specify copper as a required material for grounding purposes, in section 4.5.4:


                        Other info on lightning:

                        Paul , P S Technology, Inc. and MrTibbs
                        USA Maryland 21030


                        • #13
                          I have a couple of those as well. Likewise I am 99% convinced they are silver coated.

                          Mine are 6" wide 13"ish long and 1/4" thick possibly a bit thicker.

                          Can just see it in the top right of this pic, has the square holes in it.



                          • #14
                            my first thought was cadmium


                            • #15
                              Silver plating has been the norm for bus bars for a long time. It is fairly easy to plate copper with silver, even without using electricity. Here are some products widely used in the switchgear industry:


                              Paul , P S Technology, Inc. and MrTibbs
                              USA Maryland 21030