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Need Help With Brass

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  • #16
    Pictures

    Here are some pictures of what I'll be dealing with. I added one of the full length out of the ground so you could see what they look like and why so much water gushes out during an accident. The stopper is at the bulb out in the bottom with a 1" stem that goes the whole way to the top.

    The threads are 2-1/2" on the side and 4-1/2" on the front. The adapters must be attached permanently according to our accountant, I know, sounds crazy. If it is to be paid out of (A) account, it has to be mounted permanently, otherwise, it needs to be paid out of (B) account which is not desirable by the office. Im not sure lock-tite would be the answer.

    I am considering most suggestions, however, on the silver rods, I notice they come in different %'s like 5, 10, etc, which would be best. I also heard from one of the workers the other day that some of these older fittings are leaded in which creates a whole new problem seeing how lead has a low melting point.

    Also, the threads are sloppy on hydrants, would heating it up, threading it on tight, then letting it cool work with sloppy threads ?
    Attached Files

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    • #17
      Heat is your enemy

      The original fitting could have been press fitted. Also, I would be very surprized if it wasn't bronze, due to higher corrosion resistance. They appear very similar.

      Given the differing thermal coeficient of expansion (6e-6 in/F for cast iron and 10e-6 in/F for bronze and brass), you want to do this as quickly and with as little heat as possible. Since the material with the HIGHER coef. of expansion is on the INSIDE, heating it a lot will cause the cast iron to bust from the induced pressure.

      Answering your question about silver brazing rods, I use no less than 15% silver for brazing air conditioning lines... copper to copper alloys. But I'd recommend a 45% flux coated silver brazing rod for this job because you don't need a lot of heat to make it flow.

      It is expensive - about 10 dollars a rod - but I have made perfect joints with it connecting copper lines to steel lines. I've even used it to braze over chrome plating. The stuff will flow over almost anything. The ones I buy have a bright orange flux on them. They can be had from a good HVAC supplier.

      You'll need about 1 rod for each of these joints. DEFINATELY don't need an inch of braze. Just enough to wet it like solder.

      If the original fittings are indeed leaded in place, you will be limited to a cold joint method. Brazing or welding will quickly melt out the lead, and you will be totally screwed. You COULD possibly solder the new one on with a low temperature eutectic solder, but you will be running pretty close to the edge. Just use one 3 dollar tube of red locktite on each adaptor.

      BTW I have TIG welded brass and success depends on the zinc content. Some brasses have less zinc and can be tigged with great results.
      Last edited by Bodybagger; 03-01-2008, 08:42 PM.

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      • #18
        If they were soldered in originally how about a mecahnical fastener? Thread the two pieces together and drill and tap a hole. Run in a set screw and then drill out the allen or fill it so it can't be removed. A little leakage won't hurt.

        How about just plain old 2 part epoxy. Devcon makes a huge range of epoxy adhesives and with all that surface area you'll never get them loose. Many are thicker than locktite.

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        • #19
          Drill and drive steel pins flush

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          • #20
            from the info given this is an in situ job, so GTAW and GMAW are out, soldering? (hard or soft) silly, why put all that heat into the part?, same goes for brazing.
            epoxy? hmmm. feasible, but expensive and messy. there are one part adhesives up to the task, but price could be a concern, any adhesive has the same problem as LockTite, that is, capping the hydrant, you do not want to glue the cap on.
            LockTite? i've discussed that.
            screws, pins, etc. too time consuming.
            i'm telling you, SMAW with bronze electrodes, lowest heat input, permanant join, cheapest, easiest, quickest, depending on your artistic nature, 2 small beads at 180 degrees, 3 at 120, 4 at 90, 6 at 60, a full bead is not necessary.

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            • #21
              Even though the drilling and pinning or set screws is more time consuming, it may be the answer in the long run. Being the only welder in 2 crews of 30 guys, this would free me up so I don't get backed up on my other work. I could always weld the critical ones if necessary. Anybody or should I say ALMOST anybody can drill a hole and drive in a drift pin or set screw. This would also prevent any lead from seeping out by welding. As far as leagage, thats no concern if you ever see how they leak when the fire department uses them.

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              • #22
                Since the adapters are going to be attached with the idea of not being removed........drilling one maybe two 1/4" holes and pin should be an easy job. Cast and brass........easy to drill. Unless your pay is determined by time spent..do the easiest. Tapping is too much trouble.

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                • #23
                  Originally posted by KBar View Post
                  Even though the drilling and pinning or set screws is more time consuming, it may be the answer in the long run. Being the only welder in 2 crews of 30 guys, this would free me up so I don't get backed up on my other work. I could always weld the critical ones if necessary. Anybody or should I say ALMOST anybody can drill a hole and drive in a drift pin or set screw. This would also prevent any lead from seeping out by welding. As far as leagage, thats no concern if you ever see how they leak when the fire department uses them.
                  Kbar, it's your deal and if you're cool with pinning that's fine. question is how much 'meat' is available for the pin, having not seen the adaptors, do you have to pin through the thread?

                  also, the heat input from a SMAW would be miniscule and wouldn't affect the lead.
                  Last edited by PUMPKINHEAD; 03-02-2008, 02:53 PM.

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                  • #24
                    I agree withh pumpkinhead. You wouldn't do much more than just warm up the potential lead inside the hydrant and it requires little time and effort to do. 2-1/2" to 3/4" long beads 180* appart would be plenty.

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