Re-rounding copper tubing, repair problems

**Yersmay** · 04-16-2012, 11:38 PM

Today I helped a friend repair a hot water re-circulation line under a slab in an apartment building he owns. Apparently, the pump ran 24/7 for years and now this line has leaks. The line is 3/4 inch soft copper. I've learned on this forum that joints under a slab should be brazed, not soldered. However, no one was much interested in this, so we went ahead and soldered. The main problem we encountered was that the cut end of the copper tubing was not really round and this made fitting a slip coupling on to it very difficult. We tried various methods of cutting -- sawzall... gently tightening a pipe cutter so as to not deform the pipe. The pipe cutter worked the best but generally this problem presented itself with agonizing consistency. Is there a tool that re-shapes the cut end of a soft copper tube to make it round again? Any thoughts on this would be greatly appreciated. Thanks in advance.

**Winslow** · 04-17-2012, 12:27 AM

There is a tool made for that purpose but it may be hard to find. I usually use a brass fitting of some sort (a ball valve or drop ear 90) to round out the pipe again. Get it close enough to start the brass fitting and tap it on with a hammer, then rotate it around and the pipe will then be round enough for your slip coupling. As for brazing as long as your solder joints are good it should outlast the rest of the system.

hj · 04-17-2012, 05:50 AM

The tool consists of two parts. The first one rerounds the tubing, and the second one goes inside to restore the O.D. of the tubing, since the first one may "squeeze" it and make it undersized. Depending on the situation, and how out of round the tubing it, the two pieces may have to be used in the reverse order to get a good joint.

**Yersmay** · 04-17-2012, 06:49 AM

Thanks for the quick responses. Based on your info I found a great tool made by Reed Tool. Its model number is RCR 341. I guess it's called a 'Re-rounder'. It looks like a bolt cutter but the jaws come with a shape that defines the O.D. of the pipe. It will squeeze the pipe back into a round shape. I will keep searching for HJ's description of another tool that is used on the inside of the pipe. Thanks again!

hj · 04-17-2012, 07:58 AM

Swigtools.com has a tool that does both sides at once.

**Yersmay** · 04-17-2012, 04:45 PM

Here is a picture of the tool I found that is the re-rounding device. I assume the outer shell is placed over the pipe, then the inner cylinder is tapped in. The instructions on the Swigtools (a similar but not identical tool) site said to use a 'food grade lubricant'. Apparently, mineral oil qualifies. I'm a little worried, though, about traces of mineral oil screwing up the sweated joint. Is soap and water enough to clean the mineral oil off the pipe? Alcohol? Any other type of solvent I should have on hand? Thanks again.

**jimbo** · 04-17-2012, 05:27 PM

That swig item looks like you would need different inserts for K, L, M ???

hj · 04-18-2012, 06:32 AM

It is the same as the two piece tool, and NONE of them compensate for the thinner walls of grades "L" or "M". I never use a lubricant, because that would just make soldering the joint more difficult. The one pictured will let you use the outer one and then the inner one at the same time. Most do not have a large enough opening in the female portion to let the male one slide through. This prevents the two of them from jamming on the copper and getting stuck.

**Yersmay** · 04-18-2012, 06:45 AM

I tried to attach another picture... this time with the female section of the tool inverted. This will show the space between the male and female which allows the presence of the pipe. So the female section is divided with two diameters -- a larger diameter to allow the pipe to be present between the male and female sections, and slightly smaller diameter that fits with a closer tolerance to the male section. The shelf inside the female section butts up against the end of the pipe. I'm still not sure, HJ, how this would prevent jamming but if you feel a lubricant is a bad idea I won't use it. Thanks again.

**BobL43** · 04-18-2012, 08:54 AM

Originally Posted by hj

It is the same as the two piece tool, and NONE of them compensate for the thinner walls of grades "L" or "M". I never use a lubricant, because that would just make soldering the joint more difficult. The one pictured will let you use the outer one and then the inner one at the same time. Most do not have a large enough opening in the female portion to let the male one slide through. This prevents the two of them from jamming on the copper and getting stuck.

Ahemm.........That 55 gallon drum of personal lube on Amazon is probably water soluble and food grade

hj · 04-18-2012, 02:20 PM

When the two pieces are used at the same time, the thickness of the copper wall will determine whether the two pieces will bind together because of the copper tubing between them. Used one at a time it cannot happen, which is why the opening on the female side is smaller than the shaft of the male one so they CANNOT but used on the tubing at the same time.