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  • #31
    Originally posted by 754 View Post
    Nickel city, you or I have totally not got the concept of stitching.
    If a hole was broke out of a piece you can stitch it back in , or a crack.
    But it ain't gonna join two flat pieces together.
    Is the way I see it
    Yes, there are many types of pining or stitching.

    On a cast iron joint you drill through the crack, thread it the plug it with an appropriate screw.

    Glue it up and clean to your needs.

    The idea is the screw threads in the broken hole will actually keep the part from pulling apart. And the plugs are tiny. JR
    My old yahoo group. Bridgeport Mill Group

    https://groups.yahoo.com/neo/groups/...port_mill/info

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    • #32
      I have had luck with repairs of that sort by drilling holes and using cap screws. A couple of SHCSs would probably hold it stronger than the original CI. Come in from the outside edge. Drill with the correct size tap drill with the two pieces clamped together. Enlarge the leg holes for clearance. And if you counterbore for their heads a bit of putty would hide them completely if you paint over it. Go deep for a lot of threads in engagement for extra strength. That would probably be the neatest repair.

      I don't think that JB Weld would hold it.
      Paul A.
      SE Texas

      Make it fit.
      You can't win and there IS a penalty for trying!

      Comment


      • #33
        Originally posted by 754 View Post
        Nickel city, you or I have totally not got the concept of stitching.
        If a hole was broke out of a piece you can stitch it back in , or a crack.
        But it ain't gonna join two flat pieces together.
        Is the way I see it
        Notice how there is a cross piece that goes across the break before they stitch it lengthwise with the break with the threaded pins -- it'll hold just fine. Better than the original casting, in fact.

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        • #34
          Still haven't started this project. I just got the actual cast iron piece today. Just thought I'd update the thread with some additional pictures. I still haven't figured out how I want to approach this since it's not replaceable. Of course I could make a replica out of aluminum if I screw it up but I don't want to do that. Can't decide if I want to TIG or MIG it with Silicon Bronze or stick it with nickle rod. <duh>

          [IMG][/IMG]

          [IMG][/IMG]

          [IMG][/IMG]

          [IMG][/IMG]

          -JW:





          Last edited by Smokedaddy; 06-20-2019, 06:07 PM.

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          • #35
            I've done the braze thing, it worked but it takes a lot of heat and that seems like a big piece of metal. in my limited experience you had to get most of the work to really high temp, else it acted like big heat sink and wicked the heat as soon as you move the torch to a different spot. You guys with more experience aren't concerned about that on a large thick piece like that? I wonder about Tig brazing, never done it, but it might let you braze without worrying about the 'enough' heat challenges there may be with a torch.

            Another thought is make a new one of out three pieces of steel. Get them burned, bevel the edge and weld them together and carefully grind the weld to a nice fillet. The appeal of that is the original sits unmolested waiting to see if the steel one works out. Steel will ring more than CI, don't know if that matters
            in Toronto Ontario - where are you?

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            • #36
              Peening is very important.

              My $.02...

              "V" the break back 3/16" both sides. Clamp the pieces to a flat welding table fitting tightly. Heat with a propane weed burner or a O/A rosebud and try to get to 8 or 900f. If it is preheated hot enough the rod will flow like a good solder and look nice. Use bronze or silicone-bronze rod and borax for flux. Peen aggressively to take the tension out of the cooling bronze and prevent cracking. I use a air needle scaler for quickness but using the ball on the ball peen hammer would be fine. Clean up for appearance with a die grinder and a sander and your done.

              The repairs I've done have been successful. Even a few I didn't give much hope to.

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              • #37
                Seems like with those angles it could be drilled and tapped. JR
                My old yahoo group. Bridgeport Mill Group

                https://groups.yahoo.com/neo/groups/...port_mill/info

                Comment


                • #38
                  Originally posted by 754 View Post
                  Nickel city, you or I have totally not got the concept of stitching.
                  If a hole was broke out of a piece you can stitch it back in , or a crack.
                  But it ain't gonna join two flat pieces together.
                  Is the way I see it


                  Lock and stitch pins seal a crack, and actually push the crack apart.
                  They rely on the iron around the crack to hold everything together.
                  They are not going to hold together a broken off tab, or a piece
                  completely broken in two. Not going to work in this instance.

                  As for $10 a stick Muggy rod, no freaking way.
                  I am not paying $100 for a steak dinner either.
                  Unless it includes a happy ending if ya know what I mean.
                  Brazing rod is no where near the cost of Muggy. Get real.

                  -Doozer
                  DZER

                  Comment


                  • #39
                    I've pre-heated large pieces like that two ways:

                    - the weed burner method, which lots of folks have proposed here.
                    - or, I've put it over my Weber BBQ when the coals spread out nice and even. I use a remote IR thermometer to tell when I've got it at the temp I want.

                    Then I weld with high-nickel rod (the Muggy rods sound like they're nickel and nickel alloys), or braze it. I prefer stick welding with nickel rod after a good pre-heat. I like Lincoln's Tech-Rod 55. It might not always be machinable, but it is pretty forgiving. Last time I bought some, I think I gave $12 or $15 a pound for the stuff - that was a few years back. It probably costs more now. I seem to recall there were about 25 or 28 rods of 3/32 per pound, and something like 13 or 14 1/8th rods per pound. That's a lot cheaper than $10/stick.

                    After I'm done welding, I'll put it back on the grill and let it stay hot, adding some coals every now and again. I don't want it more than about 900F. If you have to, put some bricks under the part to raise it up so it doesn't get quite so hot. When it gets late and I'm going to go to sleep in a couple hours, I'll let the coals burn down and toss a welding blanket over the part and call it a day. I've welded up the legs on old machine tools like this. They're still holding, last I knew from the person who bought it.

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                    • #40
                      Originally posted by Doozer View Post
                      As for $10 a stick Muggy rod, no freaking way.
                      -The way I look at it, it's either a $10 stick of Muggy, or a $2 stick of braze rod, $1 in flux, and $20 in oxygen and acetylene. There's also maybe half an hour of Muggy welding, or three hours of heat-soak, braze and cool-down.

                      Take your pick.

                      While the OP's part is small enough to be brazed with relative ease, I've used Muggy, with excellent results, on parts that could not be. The base casting for my big lathe- a casting that weighs roughly 800 pounds or more- the body casting of my Arboga drill press, which has the windings for the nonreplaceable 2-speed motor solidly pressed into the casting itself, and so on.

                      Almost any one of the aforementioned techniques will work, if done with skill and care. Silver solder, braze, nickel rod, pin and bolt, etc. Muggy, in my opinion, is by far the easiest- you can basically just weld the parts, with virtually no preheat, essentially just like you're stick-welding mild-steel parts. That casting I showed above, I did just that. I'd pile weld on, let it cool, grind the excess off, fill in more weld, grind smooth, etc.

                      At no time did I preheat, nor did I worry about slow cooling with sand, blankets or any other insulator. I had the part clamped to a steel sawhorse out on the apron in front of the shop, I'd pile on a half a stick or so, let it cool a bit, pile on the other half, let it cool, move it to the [also outdoor] vise to do the grinding, lather, rinse, repeat. No cracks whatsoever.

                      Basically it cost me something like five sticks all together- I can't recall, may have been six or even seven. But it saved what was basically a nonreplaceable part- I'd been looking for a replacement for several years prior to rebuilding the saw, and none were available at ANY price. $70 in rod and a few hours' work was well worth the price.

                      Doc.
                      Doc's Machine. (Probably not what you expect.)

                      Comment


                      • #41
                        I’ve done a little cast iron welding and it certainly can be done and would make an excellent repair. However, CI welding is not simple. Since you say that this piece is “not replaceable” I would STRONGLY recommend not welding it if you are not already good at it. Either get someone who is good at it to weld this piece or do something else (pins and glue sound reasonable)

                        Frank

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                        • #42
                          Originally posted by Doozer View Post
                          Lock and stitch pins seal a crack, and actually push the crack apart.
                          They rely on the iron around the crack to hold everything together.
                          They are not going to hold together a broken off tab, or a piece
                          completely broken in two. Not going to work in this instance.

                          As for $10 a stick Muggy rod, no freaking way.
                          I am not paying $100 for a steak dinner either.
                          Unless it includes a happy ending if ya know what I mean.
                          Brazing rod is no where near the cost of Muggy. Get real.

                          -Doozer
                          Ah, OK gotcha. Makes sense now -- they need the surrounding material to "push" against, but if there isn't any surrounding material, yer screwed. I refuse to run any welding rod that I don't know the chemistry of. Usually I preheat, butter the weld with a few layers of nickel 99x (ni-rod 99) and fill/cap with 7018. Wrap it in a blanket and let it sit overnight. Works great for me on hydraulic components.

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                          • #43
                            I did a cast iron welding repair a few years ago. The broken part was a bracket from a foot powered mortising machine. I ground out a ā€œVā€ at the break and positioned the parts by bolting them to an angle iron jig. The assembly was heated to red in a coal forge. Cast iron rod and cast iron welding flux were used with an OA torch to weld the part. The welded part, still attached to the jig, was placed in a container of vermiculite and cooled overnight. The welded part machined well when cleaning up the clamping surface.

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                            • #44
                              By all means choose whatever repair method works for you.
                              The reasons that I prefer brazing...
                              If you are preheating the part anyways for electric welding, might as well keep with the torch and braze it.
                              If you get the part hot and actually weld it with the OA torch (melting the base iron and use iron filler),
                              that seems to me like good as well. The thing is, aluminum bronze brazing rod is actually stronger and
                              more ductile than the original cast iron, which is advantageous to a successful repair.
                              The advantage of OA brazing or OA welding over electric arc welding, is the temperature of the weld zone.
                              The electric arc has a much higher temperature than an OA flame. It does not have as much heat input,
                              but the higher temperature makes the high carbon cast iron get potentially glass hard and brittle if the
                              part has not been preheated very well, and post cooled very slowly. The lower temperature of OA brazing
                              has much less of a tendency to get the part hard and brittle, because the only puddle you have is the
                              actual bronze, not the base metal.
                              I have Tig brazed with silicon bronze filler, but only on smaller pieces of steel. I tried it once on a casting,
                              but I could not get enough heat into the part without creating a puddle in the base metal (bad for brazing).
                              One method that looks promising is silicon bronze Mig filler wire. I watched SV Seeker ship building videos
                              and Doug has been using silicon bronze Mig for quite a few things. It looks well suited for cast iron repairs.

                              --Doozer
                              DZER

                              Comment


                              • #45
                                Originally posted by Doc Nickel View Post
                                Almost any one of the aforementioned techniques will work, if done with skill and care. Silver solder, braze, nickel rod, pin and bolt, etc. Muggy, in my opinion, is by far the easiest- you can basically just weld the parts, with virtually no preheat, essentially just like you're stick-welding mild-steel parts. That casting I showed above, I did just that. I'd pile weld on, let it cool, grind the excess off, fill in more weld, grind smooth, etc.
                                Doc.
                                I can see an application for Muggy rod when you're dealing with a crack on a machine where tear-down would be a huge job. I've had a couple of those on farm equipment, and if I'd known about a rod like Muggy, where I didn't need to be there for hours with a weed burner, blankets and water hoses (to keep the heat from going places I didn't want it), I would have whipped out my wallet and been all over that like flies on a cowpie. There are times when time is money, and having a primary tractor down when you're planting is one of those times. It needed repaired now, ASAP to get the seed in the ground that day.

                                The reason why some of those specialized rods are spendy is that some metals cost a fair penny. Nickel ain't cheap... the Lincoln 99% Ni rod ain't cheap. It isn't as much as the Muggy rod, but it ain't cheap. Learning about it here has been very interesting, and I might well order some in, "just to have on hand..." because we all run into castings cracking sooner or later if you're around enough machinery.

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