Replies

1. 
   Guest_ | Jun 08, 2000 08:04pm | #1

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   Use flux, paste type should work.

   Next question you should ask yourself. Why is the copper pitting?

2. 
   Ed_W | Jun 08, 2000 08:39pm | #2

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   Larry,

   you can always cut out the damaged section and replace with new pipe and compression unions.

   Ed

3. 
   Guest_ | Jun 08, 2000 09:13pm | #3

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   If it were me, I'd STRONGLY consider replacing the entire run of pipe w/ plastic.

   'course I'm saying that w/ out knowing all the particulars.

4. 
   Mark_M | Jun 14, 2000 04:37am | #4

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   Its pitting because copper hates lime in soil

1. 
   Tim_H | Jun 14, 2000 07:28am | #5

   *Edsure don't like the idea of a basically unaccesible pair of compression fittings. Seems like a problem waiting to happen. granted ,this my be the best approach in this situation.Had a on-line discussion (Diffrent site)and everybody was sort of amazed that the UPC did not address the situation at all. Oh maybe I'm too cautious. Just don''t like to bury or hide them.

5. 
   Guest_ | Jun 14, 2000 09:01am | #6

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   How to solder it: Like all sweat joints: Sand the pipe well, wire brush the fitting, spread a THIN film of flux on both, heat one side until the other side is hot enough to suck solder. If the pipe just keeps dripping a little water, you'll never got all the joint hot enough until you put a Wonder Bread plug up the pipe. The pulp will blast out when you turn the pressure on.

   I was required to use flare (not compression and not sweat) underground on my 440-foot-long, 11-foot deep (-40F winters) service line. Plastic pipe was not allowed unless it was the special polyethylene pipe with a metal thaw wire built in. But in milder climates and more corrosive soils, plastic is good. Don't go to a huge size (> 1 inch for good flow and minimal pressure drop) without providing backstops for water hammer.

   If the soil is corrosive to the pipe, you could theoretically protect the pipe from further corrosion with cathodic protection - a low voltage connected to the pipe to prevent further loss of metal. This is done routinely on underground tanks.

   Another possible cause of the pits, if they are limited to the area around the fittings, is excessive acid flux left in on the on the pipe. One women report her plumber dunking the pipe in the flux, getting a huge glob inside the pipe. Months later she had leaks near the joints.

   If you do lose the service line for a while, turn it of at both ends and run a (preferable food-grade) garden hose over to the neighbors and tie into your hose bib (if you've still got an old-style hose bib without the back-flow preventer) or cold spigot in the laundry. I've done that when the utility hasn't connected me yet in a new building. -David

1. 
   Guest_ | Jun 15, 2000 05:09am | #8

   *Our plumber uses silver solder for joints that are buried. This method is also used for repairing breaks in pipes that are in the house slab. (In Dallas most residential foundations are post tension slab on grade.)

6. 
   Larry_Z | Jun 15, 2000 05:09am | #7

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   I need to repair an underground copper water pipe. A damaged section was
   recently repaired and the tubing was observed to be corroded and pitted.
   I am guessing that the new leak is caused by the previous solder joint
   failing. This is probably caused by incomplete cleaning of the old pipe.
   Emery cloth cannot clean the bottom of all the pits and the corrosion
   interferes with adhesion. Is there a good, easy way to guarantee a
   good solder joint?

   Thanks.