Replies

1. 
   JohnSprung | May 13, 2004 09:46pm | #1

   The most important thing with compression fittings is to flare the end of the pipe after you slide the parts that go there onto it.  Without the flare, you have nothing but friction to hold it, and some late night when the pressure runs high it'll pop off.  With the flare, the pressure trying to push the fitting off makes it dig into the copper pipe and seal better.

   -- J.S.

2. 
   Frankie | May 13, 2004 09:48pm | #2

   My guess is your fitting is not going on/ seated straight or the collar is too far back. Double check. If the collar was damaged by not seating fitting properly you may need to change it. That means cutting the pipe. Cutting only the collar out usually results in damagine the copper pipe.

   F.

3. 
   RalphWicklund | May 13, 2004 10:44pm | #3

   You used emery paper on the pipe? Although it's not much, you could have scratches deep enough so that the metal to metal connection on the compression ring over the pipe is not enough to stop the ooze along the scratches.

   You could have a damaged compression ring or a cracked nut.

   There's a difference between regular compression fittings and flared connections. You wouldn't flare the end because the end would not fit into the valve and there's no nose to accept the end of the flare.

1. 
   JohnSprung | May 14, 2004 09:52pm | #14

   I don't mean a big visible flare like with a flare fitting.  You just want to expand the O.D. of the end maybe 0.010" - 0.030", just enough to keep the brass ring on, not so much that it won't fit in the stop.  Roller cutters push the copper in the wrong direction, reducing the diameter.  Soldering on an NPT adapter is a better way to go, since you'll never have to cut the pipe again to replace the stop.

   -- J.S.

4. 
   mike4244 | May 14, 2004 02:56am | #4

   DO NOT use emory paper on compression fittings, do not flare the ends either. Just clean the  pipe with a rag if it is dirty. The only thing to do now is what you didn't want to hear. Replace compression fittings with a soldered one. Then you clean the pipe and fitting with emory paper and wire brush for fitting.

   mike

5. 
   tenpenny | May 14, 2004 03:15am | #5

   Are you using flared or flareless fittings?  That will make a difference.

1. 
   FastEddie1 | May 14, 2004 03:58am | #6

   Lowes sells repair kits that have just the compression ring and the nut, so if you can cut off the old one cleanly...if there's enough slack in the pipe...you don't need to buy a new stop.

   Whenever you are asked if you can do a job, tell'em "Certainly, I can!"  Then get busy and find out how to do it.  T. Roosevelt

1. 
   Wayfarer | May 14, 2004 05:14am | #7

   Great, I'm in the process of doing compression fittings on some plumbing right now.  On the kitchen sink I did the solder thing as I have three valves involved, but figured with everything else I would use compression fittings.  I don't know, what's the buzz of finish plumbing.  I mean I'm doing the work and labor, should I solder on fittings with a male thread end, or go with the compression fittings?

6. 
   RCovell | May 14, 2004 07:55am | #8

   You sound like you did everything one should do to assure a good tight fit. I've found an occasional bad fitting, everything from a bad body on the valve to a cracked nut. If you think you're OK in those areas, try this little trick: turn off the water, remove the stop and wrap about 1 1/2 turns of Teflon tape around the ferrule itself. Reassemble the stop and turn the water back on. Might work for you.

   Bob.

7. 
   WebTrooper | May 14, 2004 08:39am | #9

   Hi Rootgobbler,

   I'm assuming you're not using the flare type but rather, the type with the brass ring. I use these almost exclusively so I can replace them easily, if need be. You shouldn't have scratched them up with emery cloth, or any sanding/cleaning. That's for soldering.

   What you need to do is reinstall the fitting but this time use pipe dope (PTFE paste) around the ring and on the threads. It's unorthodox but it works. The dope will fill the minute scratches that are causing the leaking.

   ~ WebTrooper ~

   "But don't take my word for it. I was wrong once and it could happen again!"

8. 
   arrowshooter | May 14, 2004 05:04pm | #10

   If you keep tightenning it it should stop leaking.

   Look closely at the valve sometimes the valve stem nut will leak and needs tightening.

1. 
   rootgobler1 | May 14, 2004 07:31pm | #11

   To those that responded:  Thank you all so much for your input.  Note that I was refering to compression ring fittings and not to flared type fittings.  To summarize my take on the eleven suggestions I received, it looks like one should clean the copper pipe only with a very fine emery cloth or possibly steel wool and a rag to minimize scratches that might ooze water that the compression ring could not seal.  Also, to stop the oozing of water, it was suggested that a small bit of pipe joint compound (or even one and a half turns of teflon tape) be applied over the compression ring after it is assembled on the pipe.  This slightly unorthodox procedure might be the trick that could prevent any such fittings from leaking.   Someone about to do a lot of fittings might try it on all connections and let us know the results.  Lastly, thank you Fine Homebuilding for providing this forum. 

1. 
   johnnyd | May 14, 2004 09:29pm | #12

   I've always been suspicious of those ring compression fittings...to the point where I generally solder, BUT I can second that usage of teflon paste.  I also use teflon paste on PVC trap threads.

2. 
   ClayS | May 14, 2004 11:19pm | #15

   I used to do nothing but finnish plumbing and we used the compression  angle stops. I always dressed the cut copper with a highly used  emery cloth to clean/polish it. Also used pipe dope on each and evey one, slide stop on, pipe dope copper, slide compression ferl on, pipe dope it secure with cresent wrench and tighten nut. don't forget to ream copper befor doilng all this. If you have to you can cut the ferl off with a hacksaw blade but you have to be real carefull.

9. 
   DanH | May 14, 2004 09:42pm | #13

   Two tricks:

   1) When inserting the pipe into the ferrule and fitting, push it all the way in, then withdraw it a small amount -- maybe 1/16". If you don't do this, then as the ferrule tightens against the pipe it will "squeeze out" the pipe a bit and the pipe, having nowhere to go, will be forced backwards out of the fitting. The amount of motion that occurs isn't much, but it's enough to keep the fitting from sealing correctly.

   2) Use a small amount of whatever lubricant on the pipe, ferrule, and inside the nut. This will help everything slide together easily so that nothing remains "cocked" as the fitting is tightened.

   OK, and a 3rd one:

   Where possible (eg, when connecting a sink) throw out the "flexible" copper pipes and use good-quality, steel-reenforced flexible hoses. They connect to standard ferrule-type fittings but do so with a rubber gasket, not a ferrule. (I realize this doesn't apply to angle stops and the like where the pipe in question is a supply pipe, rather than just a hookup connection.)