Copper pipe ends oxidized inside near joint after soldering

[k9mlxj]

Hi,

A quick question on soldering copper pipe.

I was installing a bath/shower faucet, and when I was soldering an elbow joint on the copper pipe, it didn't solder well.

After a few attempts, I pulled off the elbow joint, and I realized the outside *AND* the inside of the copper pipes on both ends was black (oxidized). I cleaned up the outside of the tube real well to remove all the oxidization on the outside of the tubes, used a new elbow joint and brushed and fluxed all contact points, then reinstalled with the new elbow joint, and it finally went fine (no leak afterward).


I didn't really clean up the oxidization on the *inside* of both ends of the pipes though. Is that fine with using the shower? I kind of smell a bit of carbon when the water came out now. Would it go away eventually? Is that harmful?


Thanks.

[hj]

If it is "loose" it will flush out as soon as you use some water. If it is not, then it should not create a problem. You probably "smell" the carbon because you know it is there, and if you had not seen it would not know the difference. The "oxidation" was probably "water soluble" flux that you overheated, and if so there should have been very little "inside" the pipe.

[k9mlxj]

The black residue from the burnt flux was about 1 inch length into the pipe. As long as there won't be health issue it'd be fine then. It stuck pretty well in the pipe.

Just wonder, would that burnt flux inside the pipe eventually dissolve/loosen up and get flushed out later as the shower is used daily? Or it'd be stuck for a long time?


Thx.