Making split bronze bearings [ silver soldering ]

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Making split bronze bearings [ silver soldering ]

Home Forums General Questions Making split bronze bearings [ silver soldering ]

Viewing 24 posts - 1 through 24 (of 24 total)
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  • #401593
    David K
    Participant
      @davidk77137

      I need to saw a piece of phosphor bronze round bar in half and then solder it back together before machining to size for the split bearings.

      My question is, do I put flux on the mating surfaces before clamping together or leave them clean , clamp together and then just run flux along the join.

      When the piece is soldered I will need to turn the diameter down so I presume the solder will need to penetrate the join so it stays in one piece.

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      #26500
      David K
      Participant
        @davidk77137

        ]

        #401596
        roy entwistle
        Participant
          @royentwistle24699

          I wouldn't silver solder. Ordinary soft solder should be OK

          Roy

          #401605
          Brian H
          Participant
            @brianh50089

            I agree with Roy, soft solder is best.

            Brian

            #401614
            Hopper
            Participant
              @hopper

              One way is "tin" the two halves with a thin layer of soft solder than clamp the two halves together and heat until solder melts again.

              #401631
              Paul Lousick
              Participant
                @paullousick59116

                Soft solder is good enough. Thats how I did the split bushes on my engine. Apply flux to all mating surfaces and heat until hot enough to solder. Touch joins with solder and it flowed to all surfaces.

                See my post on MEW at click here

                Paul

                #401639
                Speedy Builder5
                Participant
                  @speedybuilder5

                  If the mating surfaces (After boring) are big enough, superglue can sometimes be sufficient.

                  #401641
                  JasonB
                  Moderator
                    @jasonb

                    I quite often use soft solder paste, apply a little to one face, rub the two together so they are both coated and then heat.

                    For larger bearings I'll tin (flux heat apply solder and wipe off excess) then put the two tinned surfaces together with some flux and heat again. See this post

                    #401648
                    vintage engineer
                    Participant
                      @vintageengineer

                      The best way is to use solder paste. Machine both halves flat, coat with solder paste, heat up till it melts then wipe off with a piece of leather. This should leave you with a couple of microns of solder on the bearings Now clamp the two halves together and heat up to fuse the two halves together. If you use too much solder you will have to shim the bearing after cleaning up.

                      #401658
                      Ian S C
                      Participant
                        @iansc

                        The way I make con rods with bushed and split big end, bore the hole to take the bronze for the bush, fit the piece of bronze, either a light press fit or Loctite, drill and tap for the big end bolts, now split the bearing and fit the bolts, bore the bearing to size. Usually I drill the bronze before fitting if its been in the lathe to take the OD down to size. Not too practical for main bearings, but one thing is, the bearing can't rotate in the housing, it's oval on the OD.

                        Ian S C

                        #401683
                        JA
                        Participant
                          @ja

                          My attempts at using solder and glues failed so I made a proper fixture to hold the halves. This allowed the ends to be faced in addition to the boring of the bearing.

                          A little bit of thought and accurate machining is required.

                          bearing fixture 2.jpg

                          bearing fixture 1.jpgJA

                          #401688
                          Anonymous
                            Posted by JA on 22/03/2019 12:31:32:

                            My attempts at using solder and glues failed so I made a proper fixture to hold the halves.

                            Same for me; the solder joint either gave way when machining, or the bearings required a serious amount of heat to melt the solder – not easy. Depending upon the bearing I made a simple jig:

                            Crankshaft Bearings

                            Or made a jig plus the actual bearing housing:

                            boring crankshaft bearings.jpg

                            Andrew

                            #401694
                            David K
                            Participant
                              @davidk77137

                              Well thanks for the replies, certainly given me something to think about.

                              I was worried that the solder on the mating surfaces would compromise the final bearing size

                              but I see this is not the case.

                              I will get some solder paste and give that ago first , will let you know how it goes.

                              #401710
                              Brian Oldford
                              Participant
                                @brianoldford70365

                                With any soldering operation cleanliness is next to godliness. Make sure you use sufficient flux to prevent oxidisation of the solder.

                                #401790
                                roy entwistle
                                Participant
                                  @royentwistle24699

                                  David After you've bored the hole and turned the outside don't forget to mark the halves before you split them so that the correct halves go back together and the right way round

                                  Roy

                                  #401799
                                  Rik Shaw
                                  Participant
                                    @rikshaw

                                    For historical accuracy split brasses are a nice touch but I will make mine differently. I shortly need to make 4x PB journals for the crankshaft on my current Double Tangye in progress. They will be made from solid bar, no splits, no soldering! The feed spigot on the oil cups will stop them rotating.

                                    The only splits found on this model are between the CI standards and journal caps. The completed journals will be slid onto the crankshaft then the standard caps will be fitted holding the crankshaft in position.

                                    Rik

                                    #401801
                                    JasonB
                                    Moderator
                                      @jasonb

                                      A lot depends on the layout of the particular engine and crankshaft/pin. With disc cranks and separate pin on the Tangye solid bearings are possible but they won't work if you need one in the middle of a double throw crank or your big end bearing fits between two webs of a solid crank.

                                      What I often do where it is possible to slide the bearings on is to make them as split ones but don't unsolder them, makes it easy when taking the engine apart and reassembling and less chance of mixing things up. The main advantage is if you do get wear or find your fits are a bit slack it you can simply melt them apart at a later date and treat as split ones.

                                      #401814
                                      Rik Shaw
                                      Participant
                                        @rikshaw

                                        Quite understand what you are saying Jason and I understand that not all crankshafts are equal. However, and as you point out, the DT design does allow for solid journals. My only other engine also had journals from solid. Maybe I'll try another model in the future with the split variety but until then it will remain a "pleasure" to come.

                                        Rik

                                        clovercrank.jpg

                                        #401922
                                        Keith Hale
                                        Participant
                                          @keithhale68713

                                          Hi David.

                                          Paste is an expensive solution to the problem although the technique is sound.

                                          Use a paint. It is cheaper, easier to apply and you will use less of it.

                                          Readily available from any good supplier.

                                          Regards

                                          Keith

                                          #401959
                                          BW
                                          Participant
                                            @bw

                                            Why do people want to split a bearing and then solder it back together again ? WHat is the improvement that is gained by doing this ?

                                            Bill

                                            #401964
                                            JasonB
                                            Moderator
                                              @jasonb

                                              You don't actually make it and solder back together. You solder two pieces of bronze together and then ream or bore the hole before melting them apart. two main reasons:

                                              1. A split bearing can be tightened to take up wear.

                                              2. On a typical one piece crankshaft you would never be able to fit the big end bearings if the bearing was solid with a hole in it. No other way to get something like this

                                              To fit around the middle of this

                                              #402027
                                              BW
                                              Participant
                                                @bw

                                                Thanks Jason.

                                                Got it now.

                                                Bill

                                                #402575
                                                David K
                                                Participant
                                                  @davidk77137

                                                  Well I tinned each half with soft solder then clamped them together and re heated.

                                                  Worked well, I managed to machine 5 bearings with little trouble although the bar did split on my third bearing

                                                  when I drilled out the centre, the drill pulled into the bronze.

                                                  I re soldered but this time put a jubilee clip around the outside until I had finished the bore .

                                                  #402662
                                                  Iain Downs
                                                  Participant
                                                    @iaindowns78295

                                                    Just to add a little digression to the thread here.

                                                    I've recently made a pair of bearings (cast iron) and split the cube 4 ways and then glued (off the shelf superglue) back together before boring.

                                                    This (as far as I can see has worked well). A modest amount of heat (and a sharp tap) broke them apart and a little alcohol cleaned them up.

                                                    I'll do this again!

                                                    Iain

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