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Cast Iron (repair)

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  • Doozer
    replied
    First I try to offer helpful advise.
    Then as I see it, it is fair game to be a ball buster.

    -D

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  • Smokedaddy
    replied
    Originally posted by Doozer View Post
    If I couldn't make that on a bandsaw with a piece of plate in under an hour,
    I'd turn in my ManCard. Just saying.-Doozer
    You must be a very talented individual.

    -JW:

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  • Doozer
    replied
    If I couldn't make that on a bandsaw with a piece of plate in under an hour,
    I'd turn in my ManCard. Just saying.

    -Doozer

    Leave a comment:


  • Smokedaddy
    replied
    Originally posted by pigpen60 View Post
    Would it be to much trouble to machine a new one? I'm sure someone could do a foe? finish to match.
    Heck I could do that but it would take 'me' a long time to make an exact replica. I've done that with quite a few things. If I had a CNC machine that would be a different story. Tentatively I have a plan and will pursue it soon.

    -JW:

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  • pigpen60
    replied
    Would it be to much trouble to machine a new one? I'm sure someone could do a foe? finish to match.
    Last edited by pigpen60; 06-21-2019, 06:53 PM. Reason: spelling

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  • Smokedaddy
    replied
    Originally posted by Doozer View Post
    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
    I have a small spool of SB for my MIG machine. Guess I need to read about it somewhere.

    -JW:

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  • wyop
    replied
    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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  • Doozer
    replied
    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

    Leave a comment:


  • Jim Williams
    replied
    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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  • nickel-city-fab
    replied
    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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  • fjk
    replied
    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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  • Doc Nickel
    replied
    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.

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  • wyop
    replied
    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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  • Doozer
    replied
    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

    Leave a comment:


  • JRouche
    replied
    Seems like with those angles it could be drilled and tapped. JR

    Leave a comment:

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