Aarrrghhh!

[DryFly]

We're in the process of refurbing the interior of our '73 Argosy, and I removed the plastic bathroom sink/counter combination. In order to remove it, I had to cut the hot and cold water supply lines - no big deal as I want to put ss braided supply hoses on, so I thought I could just use a compression fitting to adapt from the 3/8" copper supply line to the braided supply hose, right? I mean, what could go wrong?

Well... it seems the 3/8" copper pipe really isn't 3/8". I can't get a compression fitting on no matter what, including heating the fitting with a torch. Instead of being .375", the supply line actually mic's out at .3758. My local plumbing supply guru thinks that at some point the lines froze and expanded but did not break. Maybe.

So I'm looking for suggestions. Has anyone else run into this? I really don't want to tear the whole thing out and start over with PEX as I think I would have to go all the way back to the main supply.

Here are photos. The first shows the sink prior to removal; the next after removal; the third photo shows the two lines just sitting there, waiting for repair. In the third photo you can see the two supply lines cut off, and just below the cut, taking off to the left are the 3/8" lines that feed the shower. One of the reasons for my hesitation to switch to PEX is that these lines might also be over sized, in which case I would have to replace them too- just digging the hole deeper.

Ideas?

Thanks

[Protohyp]

seems such a short run. not like your local code enforcement it going to be in there but some short runs of flex tube (water grade) and some hose clamps. and a few beers.

[Melody Ranch]

emory paper and a few rubs.

[Protagonist]

According to ASTM B88 "Standard Specification for Seamless Copper Water Tube", nominal 1/4-inch Type K, Type L or Type M copper tubing for water supply service is 3/8 inch outside diameter, with a tolerance of ±0.002 inches for annealed pipe (suitable for compression fittings; drawn pipe, not suitable for compression fittings has a tolerance of only ±0.001 inches).

No, that's not a typo; the 3/8-inch outside-diameter copper pipe actually is a nominal 1/4-inch size.

So anyway, if it miked out at 0.3758 outside diameter, it's actually within manufactuing tolerance, since it's between 0.373 and 0.377 inches for annealed pipe, or between 0.374 and 0.376 inches for drawn pipe. No need for it to have expanded due to freezing.

Sorry I can't offer a sugggestion to mate the braided line to the copper tubing; I've never actually done a transition like that. I only know about the ASTM B88 because I've had to deal with it for work.

[rogerdodger]

Originally Posted by Protohyp

seems such a short run. not like your local code enforcement it going to be in there but some short runs of flex tube (water grade) and some hose clamps. and a few beers.

Good answer. Flex tube may outlast the rest of the plumbing.

[Lumatic]

Copper lines once frozen are just a teeny bit bigger.

I thought this was a thread about pirates. Arrghh.

[DryFly]

Thanks to all. I'm heading out tomorrow and getting flex tube, seems like the easiest thing to do.

[Protohyp]

do you need me to give you the address to mail the beers?

[Nuvite-F]

Yeah, I've run into this situation more than once. In one case, I'm pretty sure the lines had been frozen a time or two.

There are a couple of alternatives. One time I made a mandrel on the lathe to expand some sweat fittings a little to fit the swollen copper tube. It worked!

You might try Sharkbite fittings (or similar Lowe's Gator Bite) which seal on the OD of the tube with an O-ring and seem to tolerate a little diameter variation.

The flex tube and hose clamp approach will probably work OK. Use two hose clamps at each transition from copper to flex tubing. Double-clamped fittings seem to be a lot more reliable than single-clamped fittings. I don't know why.
.

[idroba]

That problem happens all the time and I have run into it too. Simple, once you understand what happened. At some point the lines froze and expanded. Now they are no longer the original diameter and you cannot get the compression rings on them. If you try to flare them, generally the flare will not work either, as the metal of the pipe is too thin due to stretching. Sometimes the flare nut will not even go over the pipe. I have had some success, if they are not to badly stretched, with the gray fittings used with gray polly pipe which used to be used prior to PEX. Even there, the fitting put over the pipe will often not work. Sharkbite fittings will not work either.

If you unsolder the short stubs you show from the fitting, and solder a new stub made from new copper pipe in, it will work fine. The stretching does not generally affect the solder fittings, that is they do not expand.

Have fun!

[Tom Nugler]

I’ve run into this problem on all three Vintage Trailers I’ve owned.
OK…. I know this is probably stupid and over the top. But that’s never stopped me before.
I’ve got a small lathe and it’s really easy to bore out the inside of a new compression fitting and silver solder it onto the expanded tubing. Now you've got a properly sized threaded end to attach the flexible supply lines to.
Yea. I know it’s not practical for most but it beats anything else in the area of smug self satisfaction.

Tom.

[Wazbro]

If you go with the hose clamps and flexible tubing get good hose clamps (I have seen a package of 6 in a dollar store if you want to replace your floor, even with double clamps) and don't get the clear hose make sure it's reinforced for pressure and double clamps is a good idea.

[DryFly]

Well this all presents a conundrum.
I wonder if I'd be opening up a new can of worms by trying to unsolder the the short stubs. idroba, have you done this before? Any tips and do's and don'ts?
Several years ago I had a 1-1/2" water line that feeds a commercial building burst. The plumber and I dug it up and he installed a rubber sleeve that was held in place with two stainless hose clamps. It is still holding strong with no issues. I wonder however if the flex tube lacks the ability to be properly compressed? I would really prefer a sweat fitting if I thought I could get the old one off without creating more issues.

I hate plumbing.

[Protohyp]

take the proper threaded copper fitting that will connect to your braided line and sweat that to whatever diameter copper pipe you have that is close to the 3/8" it can be about a 2" length then connect that with the flex tube to your existing pipes.

[FreshAir]

Braided hose and double clamps are holding after 5 years.....and I check them regularly. Like you I don't (can't) want to re plumb everything with pex.
Neil

[DryFly]

After trying everything else I could think of, including Shark Bites, I decided to use the same system FreshAir used. Here's a pic. I'll pressurize the system in a month or so (other projects are in the way - read honey do list). I'm pretty confident this will hold, but as with all my plumbing projects I'll keep a careful eye on it.
Thanks for all your help and input, as usual

[polarlyse]

NICE JOB. Looks good from NJ
But then again I'm 3000 mi. away when you pressurize.

Just kiddin

[Lumatic]

I have replace split copper with the same technique. Have not had any leaks.

[A W Warn]

I suggest you should cut a small piece of the original pile and take it with you to test fit new sweat fitting to use as adapters. You should find the fittings will have the same tolerances as the pipe. Some will be slightly larger/smaller than others.

If you do find you must use clamps and flexible pipe, slightly flair the end of the existing copper pipe to keep water pressure from pushing the flexible pipe off of the copper.

[bwoodtx]

I can tell you that old copper tubing of the 1970's is not the same size as copper tubing of today. Just went through this on a re-plumb of an Argosy. I did not want to remove the existing drain valves and wanted to adapt them to Pex. No such animal available.

One word of caution in using the clear braided tubing. If you check the specs it is not suitable for hot water use. Yes, it will work for awhile, but every time it gets hot water through it, it wil swell until it eventually it will fail. Usually right under the clamp.