Strange rust/corrosion on drain pipe?

[alexthefifth]

I'm wondering what could cause this corrosion on the outside of this metal pipe? I believe it is nickel?

I know some metals react when placed together but I didn't think plastics reacted with metals?

 

[Twowaxhack]

Chlorine based chemicals or a mixture of chemicals causing a corrosive atmosphere.
I bet you keep bleach or ajax, Comet under there

That’s chrome plated brass.

It can also eat its way through from the inside out and the chrome is the only thing holding it together.

 

[alexthefifth]

We keep comet powder there yes but don't use comet to clean anything in the sink. Are you saying just the air/fumes that are released by comet powder are enough to cause this kind of corrosion?

 

[FishScreener]

It is failing from the interior. And teh joint in the right of the picture is cocked and leaking. Get a kit and replace both.

 

[Twowaxhack]

We keep comet powder there yes but don't use comet to clean anything in the sink. Are you saying just the air/fumes that are released by comet powder are enough to cause this kind of corrosion?

Yes that’s what I’m saying. I see it all the time.

 

[FishScreener]

I'm wondering what could cause this corrosion on the outside of this metal pipe? I believe it is nickel?

I know some metals react when placed together but I didn't think plastics reacted with metals?

I think the brass is reacting with the sewer gas. Sewer gas contains hydrogen sulfide, and hydrogen sulfide reacts with copper, and thus the copper in the brass.

And if you have hard water, teh minerals in it can react with the zinc in the brass.

 

[Twowaxhack]

I think the brass is reacting with the sewer gas. Sewer gas contains hydrogen sulfide, and hydrogen sulfide reacts with copper, and thus the copper in the brass.

Sewer gas is on the inside of the pipe.

 

[FishScreener]

It is corroding from the inside to the outside, and very near complete failure. You are seeing daughter chemicals form the interior reactions as fluffy stuff on the outside, where the water doesn’t flush them away.

The hydrogen sulfide isn’t normally very reactive with copper. But in the presence of water vapors it is. Just guessing never researched it, but I’d guess that the inside of a wast line has close to 100% humidity.

 

[Twowaxhack]

It is corroding from the inside to the outside, and very near complete failure. You are seeing daughter chemicals form the interior reactions as fluffy stuff on the outside, where the water doesn’t flush them away.

You can’t tell that from a picture. It can be chemicals attaching the chrome finish.

To check I pinch it with my fingers.

If it breaks through it’s from the inside out. If it doesn’t and the finish just comes off then it’s from the outside.

 

[Twowaxhack]

Oops wrong thread. .

 

[alexthefifth]

I’d guess that the inside of a wast line has close to 100% humidity.

Interesting that you mention this, is this known to be a problem? Is it not supposed to be humid in a waste line?

 

[Twowaxhack]

I had a customer call and tell me they have a leak under one of the master baths lavatories.

I go out there and the floor of the cabinet and the walls of the painted cabinet are wet.

Dripping almost.

I dry it all up and start checking for a leak.

Couldn’t find a leak.

By the time I quit looking forward a leak the walls and floor of the cabinet were getting wet again.

The hinges were rusty, they chrome on everything was being attacked.

No smell at all.

She kept all kinds of drugs, cleaners, make up . Etc under there.

They left the cabinet doors open for a week and kept a fan blowing in the cabinet before it stopped getting wet.

Under a sink can be like a chemistry lab of chemicals that get spilled and mixed.