Small leak in compression fitting

Hey everyone. My plumbing under my kitchen sink was super corroded and figured I'd sleep better at night knowing it was fixed so I set out to do my first plumbing job since I bought my house.
I just finished replacing everything under the sink and it looks great. My only concern is one of the compression fittings that connects the copper piping coming from the faucet to the flexible faucet hose is leaking. It's not a big leak (I have to wait a minute or so for a drop to appear). I've tightened up the fitting quite a bit to get it to this point and am worried that I might bust something if I try to tighten it up any more.
Is it worth trying to get another 1/4 turn on it or will a leak like this stop leaking after a bit??
Thanks for your help!

With compression fittings, there is such a thing as "too tight". When this occurs, replacement is the only option. You'll have to cut back the portion of pipe where the compression ring (ferrel) bit into the pipe. Of course this may leave the pipe too short and replacement of the entire length is now in order. However, it won't hurt anything to give a bit more tight to see if this will stop the leak, just make sure you don't break the connection while attempting this.

Sounds like a plan. I made sure to leave a little extra length of pipe just in case I messed things up so I'll tighten it up and see how things go.

SteveDel said:

so I'll tighten it up and see how things go.

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Steve:

Trust me when I say this as I have absolutely no reason to lie:
Before you do any more plumbing, learn to solder.

Buy yourself a length of 1/2 inch copper pipe, some cheap fittings, a GOOD quality torch that mixes the fuel with air in a short tube before igniting the mixture, and some lead free solder. Follow the basic directions in any DIY Plumbing book, and by the time you end up going through those $100 of materials, you'll be proficient at soldering.

I say that because a soldered joint is the only plumbing connection I would trust inside a wall where I can't see that connection to know if it's the source of a leak. That's cuz it's an extremely rare thing to have a soldered joint leak if it didn't leak the first time it saw any water pressure.

You're already starting to do your own plumbing, and the more compression fittings you install, the more you'll regret not having learned to solder first. That's because you'll be wanting to go back and redo all that plumbing with soldered joints.

Most newbies are kinda scared of soldering, so it's an important milepost to achieve, and it's better to do that before you have all kinds of compression fittings in your house that you'll subsequently wish were all soldered joints.

Nestor that sounds like great advice. I've read enough to know that you never put a compression joint inside a wall. I planned on getting a length of copper pipe and soldering away till I was confident enough to do it for real but there were a few issues. The pipe coming out of the wall is very short. I had to take off the old fittings with a torch since there wasn't enough room to cut the pipe. I figured that soldering this joint would be pretty difficult for a noob. Another thing that kinda frustrated me was the lack of selection for copper fittings at Lowes. I probably need to find a local plumbing supply store.

I will take your advice and buy myself a length of pipe and some fittings and get comfortable with soldering. Hopefully I'll be able to replacing my work under the sink in the near future with a more permanent solution.

Thanks again!

SteveDel said:

Hopefully I'll be able to replacing my work under the sink in the near future with a more permanent solution.

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Gawd I hate to tell you this, but that's the kick in the A$$ with compression fittings. When you tighten a compression fitting onto a copper pipe, you actually crimp a brass sleeve (called a "ferrule") onto that pipe with a compression nut behind that brass sleeve. So, I kinda doubt you're gonna be able to get that brass ferrule off without cutting it off. Like, I mean, cutting the pipe behind the ferrule to remove that ferrule so you can solder a coupling onto that pipe and extend it a bit further. Do you even have room to do that?

Does anyone in here know if it's possible to cut a brass compression fitting ferrule along it's length and then pry it off the copper pipe? What tool would a person use to cut the ferrule without mucking up the pipe?

I have heard people say that you can remove a brass ferrule from a copper pipe, but how it's done, I have no clue. The force with which you've crimped that brass ferrule onto that short piece of pipe may make removing it a pipe dream.

If push comes to shove to fix that leak, undo that compression fitting, wrap some soft teflon tape around that ferrule as best you can to make a water tight seal between the ferrule and the fitting and put the compression fitting back on, but don't tighten the bygeezus out of it. Just a bit more than snug should be OK.

Watch this Plumbing forum for a post on basic instructions on how to solder. I will also explain why each step is done. If you know what you're doing and why, you'll have much more confidence doing it.

Does anyone else have any idea of what to do here if Steve can't stop that leak without busting something?

You really need to cut the pipe at the fitting. I have never been able to get one to work properly after it leaks, and I have replaced many kitchens.
Your other option is to buy a longer flexible line and another fitting if you are short on distance. Just make sure you have access to where the fitting connects.
I had this issue with my own dishwasher. I just gave up on the copper line with compression fittings and switched to a braided stainless steel flex line...no worries.

Absolutely learn how to sweat pipe...todays tools have made it easier, just be careful where you point the flame.

Most compression fittings leak due to the pipe not being pushed all the way into the fitting. This prevents the ferrule from properly seating. Old Plumbers trick for some compression fitting leaks is to run a piece of heavy string through a candle a few times. Then cut off enough to wrap around the pipe once or twice, above the ferrule, than reconnect the nut and tighten.

inspectorD said:

...<snip>.....I had this issue with my own dishwasher. I just gave up on the copper line with compression fittings and switched to a braided stainless steel flex line...no worries.......<snip>....

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Me, too and I've never figured out exactly where I was going wrong with the compression fittings.

Well I cut off the compression fitting and put in another one, tightened it up, and it's working fine. I did have a couple of questions for the future though.

First, about the short pipe coming out of the back of my kitchen cabinet. I'm guessing if I cut out the back of the cabinet and the drywall I would find a supply pipe coming up from the floor to a 90 degree fitting to the short pipe. I could use the torch to get the short pipe off of the 90 and solder in a new longer pipe, correct?

Second, my original problem was with connecting the braided flexible pipe coming from the shutoff valve to the 3/8" copper pipe going to the faucet. I had to use a 3/8" compression to 1/2" threaded connector. If I was going to go the soldering route in the future, how would things change? I guess I'm wondering what my other options would be going from the shutoff to the 3/8" pipe at the faucet?

Thank you all once again for the help.

SteveDel said:

First, about the short pipe coming out of the back of my kitchen cabinet. I'm guessing if I cut out the back of the cabinet and the drywall I would find a supply pipe coming up from the floor to a 90 degree fitting to the short pipe. I could use the torch to get the short pipe off of the 90 and solder in a new longer pipe, correct?

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Well, if you did cut out a big section of the back of the cabinet and the drywall behind it, yes you could do that, but a smarter plan would be to just cut a small hole in the cabinet back where the pipe comes out, and solder a coupling and a longer pipe onto that short pipe. Then, cover the hole in the back of the cabinet where the piping comes out with a "split escutcheon":



That would look a bit more civilized.

You should also inquire about "Sharkbite" fittings, which you simply push over the end of a 1/2 inch copper pipe to make a connection. I've never used them, so I can't comment on them. But, you should certainly investigate whether they would work for you. Also, one of the biggest manufacturers of copper fittings in the US is a company called Nibco. They have new ways of connecting 1/2 inch copper piping, and you might want to snoop around their web site to find out what they have that might work for you.

Second, my original problem was with connecting the braided flexible pipe coming from the shutoff valve to the 3/8" copper pipe going to the faucet. I had to use a 3/8" compression to 1/2" threaded connector. If I was going to go the soldering route in the future, how would things change? I guess I'm wondering what my other options would be going from the shutoff to the 3/8" pipe at the faucet?

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What I would do if I were you is...

Once you learn how to solder, and your compression valve starts leaking or looking like it needs replacing, then cut it off and try soldering a coupling and piece of pipe onto what you have coming out of your cabinet. That way you can just extend your existing short pipe. If it's just plain too short to solder a coupling onto, then use a hole saw to cut a 1 1/2 or 2 inch hole in the back of the cabinet to give you more room. If that still isn't enough, you can cut a bigger hole once you've got a plan in place to cover it, and that won't be very hard.

(I'm thinking you might buy a 6 inch hole saw for cutting holes in ceilings for recessed lighting, and then use a clean out cover for a 6 inch diameter gavanized chimney duct to cover that sucker.)

Once you get a copper pipe coming out of the wall, I'd solder an elbow onto it, then a 1/2 inch ball valve, and then you're never going to have a problem getting from a 1/2 inch copper supply pipe into your faucet. If you couldn't do that, then your faucet manufacturer would be in big trouble and more concerned about that situation than you.

I'm not that familiar with the names of the different adapter fittings, nor do I know what kind of connections are on your faucet, but be assured that you're always going to be able to get from a 1/2 inch copper pipe to any faucet in the world.

When you go shopping for a ball valve, make sure it has a packing nut on it so that you can tighten the packing on it. Some manufacturers are making ball valves without packing nuts. Their position on the matter is: "Our valves never leak past the packing, so you'll never need to tighten a packing nut cuz it's never gonna leak, so we don't need packing nuts." To me, that circular logic completely ignores the inevitable possibility that despite the manufacturer's assurances, the ball valve still might leak past the packing. I wouldn't buy any ball valve that didn't have a packing nut to allow me to tighten the packing just in case.

Thanks Nestor, I like the idea of the coupling way better and will most likely go that route once I feel comfortable enough. Thanks for putting up the post about soldering as well, I really appreciate the insight.

I just wanted to add a few comments:
Sharkbites are the greatest thing since sliced bread. They are expensive but, makes basic plumbing a no-brainer for any noob. However, I would use them extensively in lieu of a soldered joint.

Also, if your going to solder, use MAPP gas and save yourself a headache. MAPP gas comes in a yellow cylinder rather than propane gas which comes in a blue cylinder.

Kok328:

Shouldn't the sentence that reads "However, I would use them extensively in lieu of a soldered joint." read as either:

However, I would not use them extensively in lieu of a soldered joint.

or

And I would use them extensively in lieu of a soldered joint.

You've got a "however" in there that warns us that what's going to be said next runs contrary to what's already been said. But, that doesn't happen and so it's a bit confusing.

About using MAAP gas: I know most plumbers do, but I can't help thinking that for people new to soldering it might be more cautious to advise they just stick with propane until they become proficient at soldering. I use propane only because I've never had a good reason to switch to MAAP gas. As long as you mix the fuel and air before igniting the mixture, propane burns plenty hot enough to do the job. I haven't had a solder joint leak on me since I was using a pencil tip torch, and that's gotta be about 15 years ago or more. So, I can't really understand why you say "use MAAP gas and save yourself a headache." I have no troubles whatsoever soldering 1/2 and 3/4 inch brass and copper with propane and lead-free solder.

This is a nice "study" on how to solder and what really works.
I use Mapp gas, the reasoning is, it heats the pipe a heck of lot faster than propane. Having a flame for a shorter span of time is always a better way to start. When I started soldering I was using a propane torch and almost gave up. The reasoning was a little bit of water left in the line took forever to steam out, and the joint would not hold.
And I know all the water needs to be out, but in a perfect world that is not always what we are up against.

Nestor, you did a fine job of helping folks get a start on soldering, they can only get better at learning from here on.:rofl:

Thanks Nestor, you are correct, I used improper grammar. What I meant to say is that I would not use sharkbites in lieu of a soldered joint when doing large jobs consisting of numerous connections.

re: MAPP gas; like inspectorD indicates, use MAPP gas and you won't get frustrated with learning/using soldering techniques due to the short-comings of propane versus MAPP.

In the meantime, it appears that I need to sign up for a grammar 101 class at my local elementary school.

Thanks for correcting my post, I guess I shouldn't wander out of the electrical and HVAC forums.

you don't have to cut off the fitting. We bought a "Handle and Sleeve Puller Kit" at Home Depot made by Brass Craft. You just attach the clamp behind the nut (compression ring inside) and turn the screw which pulls the compression ring & nut off the copper pipe. Way easier then cutting the compression fitting & risking cutting the Cu pipe. You may have to trim up some pipe so that the new compression fitting compresses on a fresh spot on the pipe.
If you put a new compression fitting on a on spot it will leak.

also check out a product by ProBite that does not require the compression fitting. I found it on line, but can't find it in the stores.

To remove a leaking ferrule from copper pipe, just use a Dremel tool with a small abrasive disc attachment on it, and then sort of grind away a small slot into that brass ferrule. Don&#8217;t cut all the way through the ferrule or you&#8217;ll nick the copper pipe, just grind a slow about 80% to 90% of the way through and then stick a straight-edge screwdriver into that slot and twist it to break the ferrule open. ( I read this on Wikapedia. )

I hate compression fittings because you&#8217;re not supposed to tighten them &#8220;TOO&#8221; tight, only tighten the nut finger tight and then use a wrench to twist another 1/2 turn more.
I just did some tests on a compression type of fitting and some small bits of scrap 1/2" copper pipe and this is what I've found out: You cannot just begin turning from the "finger tight" position because some brass ferrules are larger than others, so you need to first begin tightening the compression fitting down, and then after anywhere from about 1/4 to 'one-full' turn of the nut (With an adjustable wrench) you will begin to notice that the twisting is not so easy anymore, and this is where the brass ferrule is actually clamping down on the pipe. It is from this point that you need to turn 1/2 extra turn MORE.

Once this was all done I looked inside the test pipe and I could see the spot where the brass ferrule has actually reduced the diameter of the copper pipe, so you don't need to worry about this pipe "POPPING OUT" of the compression fitting, it is firmly in there for sure !
( By the way, always have extra brass ferrules on hand, they cannot be re-used once they've been squeezed down like this.)

As for the sealing of any possible gaps between the pipe and the ferrule itself; that's where the guesswork comes in. If your pipe is new with no deep scratches then you don't need anything added, just the pressure of the squeezed ferrule should do the trick. But if you've used sandpaper to remove old paint or corrosion or something like that, then there's a ton of deep scratches and no matter how much you tighten that little nut the water's going to leak out through these deep scores, and this is where you probably need some type of liquid to seal the gaps between the pipe surface and the ferrule, either liquid thread sealer (Permatex) or liquid waterproof epoxy will do the trick (I prefer the epoxy for a gap-filler). Apply a thin layer to the pipe where the ferrule will be, and then slid the ferrule into place over this layer of liquid sealant, and then slide the nut into place, and then tighten it as described above.

Just make sure you don't use a type of liquid that hardens too fast because if it does then it will crack once you tighten the ferrule, and then the water will leak out anyways. You want to tighten the ferrule and only THEN do you want that liquid to harden (after an hour or so), sealing the gaps in all those hair-like grooves.

I have seen those &#8220;Sharkbite&#8221; fittings, I think they are so cool ! From everything that I have heard about them they are just about PERFECT in every way! So my advice is if the fitting is in an area that is visible, and the pipe surface is nice and clean, then go with those "SharkBite" fittings. Just make sure you buy that small tool to remove any burrs around the edges of the pipe, as any burrs will make a cut / score in the O-ring inside the SharkBite fitting and this is where you leak will occur. If you remove the burrs on the cut pipe then you will never encounter any leaks with the Sharkbite fittings.

However, if you sanded the pipe to get rid of any oxidization or layers of paint then the water will come out through those hairlike scratches that the sandpaper left, the O-rings only work on perfectly NEW pipe surfaces, not old pipe that has deep surface scratches / defects in them. That's the main problem with those "Sharkbite" fittings as I see it.

My favorite type of easily-removable / adjustable non-solder fitting are flare fittings. I use 5/8" flare fittings on 1/2" rigid copper pipes, they NEVER ever leak! But you need to have expensive flaring tools, and trying to find 5/8" flare fittings at Home Depot is not always easy. And those fittings are not pretty either, they just basic brass, they are not chromed and pretty looking the way customers want things these days.

For small plumbing repairs or new connections, look into a product called "Shark Bites", they are simple to use as an alternative to soldering.
They are readily availabe at the big box stores.

If you can't solder you can buy expensive Shark Bite fittings. no solder works on pex, cpvc, or copper