Repairing copper pipe

What is the service? Freeze, as in water?
Mueller® Pipe Repair Products - Mueller Co.

Copper.org: Plumbing: TechCorner - Soldering and Brazing Explained

How to Fix Cracked Copper Pipes - Yahoo Voices - voices.yahoo.com

most likely its solder, perhaps silver solder if it was a high pressure application. you need to cut the split out and solder in the same size pipe with copper couplings, you can find most of that stuff at a home center like Home depot or a better hardware store

If you are not experienced with this type of high temperature soldering, there is mechanical connection method.....video instruction for this repair....start at 1 min...

https://www.youtube.com/watch?v=UE9WbTFLnTI

SharkBite fittings....

You don't say what medium is outside and inside the pipe and the pressures involved. The problem with trying to cut out a section and use couplings to install a new piece is this - since copper is very malleable a considerable length may have been 'hydraulically' expanded beyond the section that split. If so, a coupling will not fit over the pipe. If this is moderate pressure water inside with a low pressure medium on the outside, you might try cleaning the sides (edges) of the split, then squeeze the pipe/tube back together and solder or braze the crack back together. (Or solder/braze a 'band-aid' over the split.)

reminds me of a couple of drain lines in 15 degree freezers I've repaired

It is more likely to be silver-solder, or brazing, although regular solder will provide excellent service at temperatures up to, oh, say 135degC, so it depends upon the wetting materials each side of the coil and their temperatures and pressures, which haven't been mentioned in the original posting.

The best repair is to chop out the affected section for scrap, and renew it.

You dont weld Cu pipe, you braze it.

In reality,copper pipe can be soldered,brazed, or welded.

Soldering occurs at below around 840F.

Above 840F is considered brazing.

And of course, welding is accomplished at the melting point of the particular alloy of copper,which is around 1981F for copper.

Yes copper pipe can be welded with the tig process and a footpetal to control heat, however it is not practical for a repair job.

Thanks for all the comments. What I found out was that a hand held wire brush was not enough and after using an electric wire brush, the weld was definitely done with brass. Look first and then speak, aye.

Solar Eagle hit the nail on the head. The Sharkbite fittings are the easiest way for a non-welder type person to do the job. I have used them,and They do not leak, and are very simple to install.

Cut the pipe, debur it, and press the fitting on.You will need a short nipple of the same type as the leaking pipe, and 2 fittings,unless the split is very short. That's it.

I know how to sweat and\or silver solder copper, but for household water supply,I will never solder again.

The higher temperature (and price) silver solder I will reserve for A/C units and high pressure systems.

Good luck.

A GA to Solar Eagle!