Thread: What is this material?

I see this about once a year. I have never confirmed what this gray metal tubing is.
tubing1.jpgtubing2.jpg

Please, tell me what this stuff is?

Looks like tinned copper. Never saw it before.

Originally Posted by Mark Reinmiller

Looks like tinned copper. Never saw it before.

I can't find any examples of copper tubing tinned on the exterior, but I agree that that's what it looks like. Interesting that no one else has commented, which indicates that it may be very rare.

When sweating copper, the pipe is wiped off to remove the excess flux, otherwise the area will green. If there is also excess solder it will adhere. I think this plumber was on a mission (or was smoking pot).

I have seen exposed copper tinned in order to change the appearance.