View Full Version : Trouble with copper fittings

11-11-2008, 09:34 PM
I am having trouble with 3/4" copper fittings being too tight on type L tubing. I purchased most of the material from Home Depot. I know many professionals question the quality of materials from HD, preferring to patronize their local plumbing supplier instead. With the cost of copper, I was trying to save $$. Most of the fittings are Nibco brand. I know a lot of the tubing in the racks is pretty beat up, but I avoided any tubes or fittings that were obviously banged up. I'm using a quality Rigid tubing cutter, an Oatey 4-in-1 wire brush tool for cleaning, and an Oatey inner/outer tubing reamer. Sometimes the parts slide together ok while dry fitting, but after dressing everything up nice an shiny they don't fit, even with considerable force. I really don't get that, as the wire brushing is removing some material - shouldn't it make the parts easier to slide together??? I realize the wire brushing slightly roughens up the material, but it shouldn't be an interference fit. I've tried using plumbers sandcloth as well, with the same results. I also thought the paste flux (Oatey brand) would act as a lubricant, but that is not the case. I am reluctant to sweat any fittings that are force fit, as I know to get a proper joint there needs to be a slight gap for the solder to flow into. I'm spending way too much time on joint prep. Are these brands ok, or is the problem out of round fittings or tubing due to mis-handling? I'm thinking of taking it all back for a credit and finding a good plumbing supply house. Also, anyone have any slick tips for correcting slight out-of-round fittings/tubing?

My background:
I learned to sweat solder copper plumbing decades ago, but I've done it infrequently in between. I know how to use the torch, and I'm not having any problems with the actual soldering, just fitting the parts.

Project background:
I am repiping my entire house water supply lines with copper type L tubing. The house originally had rolled copper tubing under the slab. I've had two leaks over the years - 1) a very poor solder fitting where the rolled tubing came up into the kitchen; and 2) a leak developed in the middle of a hot water line under the slab. I decided to bypass the under-slab piping with new copper tubing in the attic. I successfully bypassed just the offending line, but since I had to open up some walls I wanted to do the whole house before I closed everything up. Since the house is almost 30 years old, I felt that the second leak that developed under the slab could happen elsewhere at any time.

11-11-2008, 10:39 PM
Cutting type L can leave a ride on the end of the pipe.
Just cut that off with a sharp edge.
It's not the fittings.

11-11-2008, 11:21 PM

Thanks for that tip. I thought the outside reamer was supposed to take care of that but apparently it's not a very good tool, or I don't know how to use it. I'll pay special attention and look for a ridge on the cut tube.

Btw, this is the best forum I've seen for a wide range of work. Thanks for providing this, and thanks to all who contribute their expertise.


11-12-2008, 06:45 AM
A file or good emery cloth will reduce the ridge. Advancing the cutter wheel slower so there is less ridge produced and the rollers can depress it as it forms also works.

11-12-2008, 11:20 PM
If slowing down how fast you tighten down the thumbscrew does not fix the problem, ensure your cutting wheel is not badly worn. You should be able to get a new cutting wheel at any supply house that carries Ridgid. It should not be more than a couple bucks.

Unless they have gone down in quality lately, Nibco fittings are as good as any out there.

11-13-2008, 07:26 AM
It should not be more than a couple bucks.



But you are right on with the idea....dull cutter blades make problems.

11-14-2008, 03:47 AM
Thanks for the tips guys. Gotta say though, I'm still struggling with it. I knew that advancing the cutter wheel with too much force could distort the tube or cause a higher ridge, so I've been careful about that. I think the blade is still in good shape. If I had any doubts about that being the cause of all this grief I'd gladly spend the 8 bucks for a new wheel, even though that seems pretty steep. But I'm making darned sure that there is no ridge left as I dress the end of the tube, then I take the emery cloth and wire brush to the tube and fitting. The really weird and maddening thing is that I can slip the fitting on and off dry no problem. But when I flux the fitting and try to slide it on the tube again it's like it has superglue on it instead of flux. Get it maybe a third of the way on and it doesn't want to go any further or back or spin. The flux is working as it's supposed to when I finally get a fitting all the way on and put the solder to it. But it is so frustrating getting the pieces reassembled in place, especially in the tight area I'm working right now between the joists and rafters. Flux is cheap, maybe I'll go find a different brand, or just fresh, though I don't see anything wrong with what I've got (other than the glue-like properties). I'm thinking of making a video of my struggles, just to show I'm not making this up. I can't believe something so simple is giving me so much grief. Come to think of it, I'd have to heavily edit the video toward the end, otherwise I'm sure I'd get into trouble for saying all the seven words George Carlin made famous, and then some. Oh well, just airing it out here, I don't know what else you can tell me. Still plugging away, slow but sure.

Thanks again,

11-14-2008, 07:58 AM
As Jeremy in the comics would say, "By now you should have given up and called a plumber."

12-29-2008, 10:14 AM
MP, I feel your pain. I am having the exact same troubles. I will be checking my tubing cutter. I put one elbow on and turned it and it locked. It absolutely will not come off, turn or budge in any way. It's like it is welded together....but it was a dry fit. ARRRGH!. If it's not the fitting, it must be the 3/4" copper I'm using....Home Cheapo of course. It's driving me nuts. I haven't done a copper job in quite a few years but have never had a problem like this. I thought it was the NIBCO fittings too but I bought some from another source and same thing.

I'll also turn the wheel slower on my cuts. Good thing my kids we not there yesterday to see the show!:eek:

Gary Swart
12-29-2008, 10:44 AM
It is my opinion that pipe is pipe and fittings are fittings no matter where you buy them. Certainly pipes can be mishandled and ends buggered up, but that could happen anywhere. Big Box stores don't make pipe and fittings, they buy them from the Chinese or Korean manufactures just like every one else. You might try a small flat file to knock a ridge off, but I think better cutting technique will solve your problem. And yeah, it's a b***h when you dry fit then can remove the fitting, but it will come off. I avoid dry fitting for that reason. PVC and ABS pipe are even worse. NEVER dry fit plastic pipe.

12-29-2008, 11:21 AM
I'll mail you the pipe with the elbow. I could'nt get it off even using a workbench vice. About a foot of 3/4" copper and an unsoldered elbow.....Oh, nevermind, I just remembered it's on my neighbor's roof now!:D

12-29-2008, 11:59 AM
FWIW, the ridge is usually only on one side of the cut. If you can figure out which side, you can swing the cutter 'round to always have the ridge on the scrap piece.

As far as the wedged-together fitting & pipe, to get them apart, try heating the fitting so it expands a bit, then pry them apart.

Gary Swart
12-29-2008, 01:22 PM
It would be an interesting challenge! I can think of a couple of ploys to try, including heating. One trick that might work would be a piece of 1/2" pipe inside the fitting and using that as a lever. Another would be a drive punch to tap on the edge of the fitting. In the real world, I'd probably punt, cut the damn thing off and save the pipe.:D

12-29-2008, 08:03 PM
The really weird and maddening thing is that I can slip the fitting on and off dry no problem. But when I flux the fitting and try to slide it on the tube again it's like it has superglue on it instead of flux. Get it maybe a third of the way on and it doesn't want to go any further or back or spin.

You've got to use some finesse son:) Plumbing aint as rough as people think it is. Sometimes you have to romance things a little bit. It's all about the twist.

12-29-2008, 08:34 PM
And there's no reason you cannot use a file if you need to knock that lip down a bit prior to fitting.

Dunbar Plumbing
12-29-2008, 08:46 PM
Slooooooooooooooooooooooow down when you're cutting that tubing; that makes a difference right there.

12-30-2008, 05:58 AM
The cutter wheel is a V so it displaces metal on both sides which will create a ridge on both sides. Some fittings are tight on one side and loose on the other, possibly because of handling or manufacturing tolerances. Put a piece of copper into the other opening and rap it off with a hammer.

12-30-2008, 04:56 PM
You've got to use some finesse son:) Plumbing aint as rough as people think it is. Sometimes you have to romance things a little bit. It's all about the twist.

:eek: Like a bull in an antique store.

12-31-2008, 11:27 AM
With fittings getting stamped out in China these days it's not uncommon to come across fittings that you can't fit into. Also if the fitting is slightly crushed it can be impossible to get it in without a tool to fix the fitting's shape. This is not a commonly found tool anymore.

Most importantly, use a Rigid cutter. The cheap ones you can buy will leave ridges as mentioned earlier. If your cutter is giving you a ridge on the outter side of the pipe, return it as defective if it's new, and go out and buy a Rigid cutter.

The reamer you have is to remove the inner ridge created from cutting the tubing. That ridge can cause ventricles which will spin around in the pipes till it hits a joint then it will wear a hole in the pipe next to the fitting or through the fitting itself. Reamers I get usually spin one way easierly (clockwise I think). Reamers that are part of a tubing cutter is a sign of a crappy tool. If you ream, get a dedicated reaming tool along w/ the better tubing cutter.