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  • Antique machinery repair, appearance and originality.

    I have just bought an ancient power hacksaw, a Perfect Tool Co no 3 built in Galt Ontario.
    I intend to use the machine, but also to make it somewhat of a showpiece.
    The vice has some damage to the casting where the screw fits the moving jaw and the screw, while fully able to close the vice does not pull it open due to the missing piece. An earlier welded and again broken repair is evident.
    I seem to have two courses of action here, spend a lot of time and effort making an "invisible" repair which would likely somewhat weaken the casting, or make a visible neat looking period correct repair( No allen head screws visible).Leaving it at full strength.
    Are there any suggestions as to what I should do?
    I do not intend to resell the machine, but do wonder how my choice might affect its subsequent value,
    Regards David Powell

  • #2
    Most of my older machines carry the scars of their past lives, I think an honest repair is just part if the character of the equipment. My tools are used so I'm not going to lose sleep over worn paint. Fix it right so that you can use and enjoy it.

    Jerry

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    • #3
      I second the above. Do a neat and appropriate repair and then use the machine. In general, these are not museum pieces and were intended to be tools for daily use. Repairs are just part of their history. I can appreciate a nice restoration but unless you are building a museum collection, expending huge effort to make invisible repairs seems unnecessary to me. Particularly if you end up with a weaker inferior repair.

      If you enjoy the process of doing a museum quality repair for its own sake, well that's a bit of a different thing I guess.

      For something like a power hacksaw I am not sure resale value comes into it all that much. I don't think there are a lot of power hacksaw collectors out there who would agonize about a well done but visible fix, though maybe I just run in the wrong circles.

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      • #4
        A visible neat looking period correct repair sounds like the way to go. Make it so you're happy with it.

        Location: Saskatoon, Saskatchewan, Canada

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        • #5
          When I look at old machines and accessories the most interesting parts are the repairs, good and even sometimes bad, but I like to see the honest attempt to make the best of a bad situation, within the constraints of time, budget, available supplies, etc.

          Some of the most clever farm equipment repairs use pure crap for materials, (baling wire and license plates, etc, but there is something very artistic, skilled and admirable in “doing the best you can with what you’ve got”.

          I guess my approach on old machine tool repairs is to try to equal what the best hand in a typical shop would have done. I usually end up with the third best guys result but I have my aspirations.

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          • #6
            It comes down to your preferences, but I think that honest repairs to old mechanical things adds to their charm. I have a 1903-vintage General Electric "pancake" fan that had accumulated numerous, neatly executed repairs to the brass blade guard, and elsewhere, before I bought it ten years ago. I don't know what its original working life was before it fell into disuse, but it has been resurrected and now does regular duty in our kitchen. Back in the day, this would have been a very large purchase for the average family. Its very visible repairs recall a time when people made do with what they had.

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            • #7
              In my opinion, a well done machine repair
              is a work of art. A poorly done machine
              repair is just embarrassing.

              -D
              DZER

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              • #8
                Well, the vice is repaired, the repair is obvious, but neat and tidy and as strong, if not stronger than the original part of the casting. Now comes the next decision.
                The motor, the controls and motor mount are obviously later additions, but certainly very old, There is a DC motor, variac, and positively lethal wiring
                Should I attempt to get this lot safe and working properly, or simply replace with new, A Consew 3/4 hp motor and electronic controls seem a good answer.
                Any and all suggestions are welcome. Regards David Powell.

                Comment


                • #9
                  This post just gave me a "knee jerk brain reaction"

                  so many times on here we see these cast structures broken or cracked with the OP asking "how do i fix this"

                  and all the reply's after like "braze it" or "nickle weld it" and on and on,,,

                  and for all I know this has already been mentioned but thought worth bringing up especially with Dave's need to make it look "unmolested"


                  So what about putting the broken pieces together - perfectly - even with super glue or whatever --- then carefully placing it in a fine sand bed and packing it stage by stage and then heating the whole mess up to well past melting point - I would think this might work as is with aluminum - maybe C. iron might take an oxide of some kind instead of sand dunno the finer details at all - but what say the casters ?

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                  • #10
                    Originally posted by A.K. Boomer View Post
                    This post just gave me a "knee jerk brain reaction"

                    so many times on here we see these cast structures broken or cracked with the OP asking "how do i fix this"

                    and all the reply's after like "braze it" or "nickle weld it" and on and on,,,

                    and for all I know this has already been mentioned but thought worth bringing up especially with Dave's need to make it look "unmolested"


                    So what about putting the broken pieces together - perfectly - even with super glue or whatever --- then carefully placing it in a fine sand bed and packing it stage by stage and then heating the whole mess up to well past melting point - I would think this might work as is with aluminum - maybe C. iron might take an oxide of some kind instead of sand dunno the finer details at all - but what say the casters ?
                    Interesting thought process.
                    Might have to add some additional material to the pour spouts (I forget the casting term)
                    but an interesting idea for sure.
                    But maybe better to make a mold as you say
                    and use new material. Because if anything effs up
                    your pattern would now be gone.
                    -D
                    DZER

                    Comment


                    • #11
                      If you do a braze repair, and vee the material out from both sides
                      and grind the finished repair flush, you will never know it was there
                      and you will have one hundred percent penetration, so what is better
                      than that ?

                      -D
                      DZER

                      Comment


                      • #12
                        I have helped repair some broken castings. Welding or brazing has worked in many instances, but welded repairs have sometimes failed in cases where the cast iron has been well soaked with oil in its working life. Even repeated heatings have sometimes failed to boil out all the oil. Sometimes , having new castings made has been the only durable solution.
                        regards David Powell.

                        Comment


                        • #13
                          Originally posted by A.K. Boomer View Post
                          This post just gave me a "knee jerk brain reaction"

                          so many times on here we see these cast structures broken or cracked with the OP asking "how do i fix this"

                          and all the reply's after like "braze it" or "nickle weld it" and on and on,,,

                          and for all I know this has already been mentioned but thought worth bringing up especially with Dave's need to make it look "unmolested"


                          So what about putting the broken pieces together - perfectly - even with super glue or whatever --- then carefully placing it in a fine sand bed and packing it stage by stage and then heating the whole mess up to well past melting point - I would think this might work as is with aluminum - maybe C. iron might take an oxide of some kind instead of sand dunno the finer details at all - but what say the casters ?
                          I don't have any real qualifications as a foundry guy, but I have seen it done in person at a small scale commercial aluminum sand casting operation.

                          While the logic is sound, the devil is in the details. I could be way off here, but I don't think this will work because during the slow rise in temperature to the melting point of the metal, all of the moisture in the sand would be driven off and then the mold just becomes a box of dry sand that will not hold the shape of the mold cavity. Once the metal melts, the cavity will crumble.

                          Green sand casting works like it does because the moisture absorbed by the clay in the sand mix binds the sand grains together. When you pour in the metal, the sand contacted by the molten metal will dry out and steam off the moisture, but the stuff just behind it maintains the shape. The pressure of the molten metal holds the shape of the cavity. That is why it's important to fill the molds quickly and why the molds typically have relatively large sprues. The column of molten metal in the sprue maintains pressure in the mold and supplies a bit of additional material as the metal cools and shrinks.

                          Now if you stuck the parts together and then encased them in a ceramic like used for investment casting, then maybe it could work. I don't know enough about the chemistry of molten metal to have any idea how much the metal composition might change if remelted and then just left to re-harden.

                          Interesting thought, really.

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                          • #14
                            Let me just add this...
                            If you have welded iron castings before
                            and got bad results (and you will if you do
                            not follow PROPER preheat and PROPER
                            post cooling and PROPER joint preparation),
                            you really need to try bronze brazing.
                            Maybe you don't own a set of tanks so you
                            welded it. Maybe you are a shortcut Charlie
                            and lie to yourself thinking it will be fine if you
                            don't follow weld procedures, whatever.
                            But if you are serious about cast iron repair,
                            then buy some torch tanks. Get serious and
                            do proper joint prep. Get serious and buy
                            some fire blankets. If you are getting poor
                            results and blame the method, maybe it is
                            YOU because YOU control the process.
                            You do the research. You practice and get
                            good at brazing (or welding). It is the level
                            of seriousness that you approach the job
                            with that determines the success. Not the
                            process, be it welding or brazing.
                            And let me assure you, if you can't master
                            brazing or welding, then you are not going
                            to be successful at casting. It takes way
                            more discipline to be good at casting than
                            it does to master brazing or welding.
                            If you are not good at the easier processes,
                            you are for sure not going to be good at
                            a more difficult one. Just giving food for
                            thought.

                            ---Doozer
                            DZER

                            Comment


                            • #15
                              Just FYI, I weld for a living, including cast repairs on occasion.
                              For cast iron, I like to bake it with the torch or whatever is handy, till all the impurities (oil, paint, etc) are gone.
                              If you must vee out a crack, make *sure* to use a carbide burr - grinding will smear the graphite and make things impossible.
                              Sometimes it is helpful to drill a small hole on the end of a crack that doesn't go all the way.
                              This keeps the crack from spreading.
                              Now that your part is toasty (at least 600F) and clean, I prefer to lay 3 or 4 layers of Nickel-99 rod (nearly pure nickel).
                              It has more strength than the cast, and alloys well with iron. It is far more ductile.
                              I prefer to peen very thoroughly in between passes with an air chisel and pointed tip.
                              I finish the repair with good old 7018 on top of the nickel, peening every time, and then wrap in a fire blanket to cool.
                              I've *never* had one fail after repair like this. In 30+ years, This includes farm implements, heavy equipment, and (large, expensive) engine blocks/manifiolds.

                              The technique works because nickel does not react with the carbon in the casting, regular steel rod does. Making a very brittle HAZ. Therefore put nickel down first, then regular steel over it. The nickel provides a "buffer zone" for things to move around as it cools.
                              For the same reason I love nickel for stainless repairs -- SS is *very* sensitive to both the carbon and the chromium precipitating out of the weld as it cools.
                              Last edited by nickel-city-fab; 06-06-2021, 08:02 PM.
                              25 miles north of Buffalo NY, USA

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