Said It Here

Is dark brown metal under paint copper?

Scratching away paint on a pipe often reveals a dark brown color instead of a shiny finish, leaving people unsure if the metal underneath is actually copper. This ambiguity makes it difficult to determine the actual pipe material or whether connections need to be cut out.

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    Scraping away paint to check the color
  2. 2
    Sanding the oxidation to reveal shiny metal underneath
  3. 3
    Checking if the pipe can be dented with a fingernail or crushed by hand
  4. 4
    Leaving the connection alone if it is not leaking
  5. 5
    Consulting a licensed plumber
  6. 6
    Replacing the connection using a proper transition donut or gasket with lead and oakum, or using a fernco

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.

r/Plumbing2 people · September 2026

Is this an approved connection or should I cut out the hub and fernco?source ↗

miakpaeroe · r/Plumbing · 8 upvotes

I scratched away the paint in the second pic and it was this brown colour under.source ↗

PristinePea9377 · r/Plumbing · 1 upvotes

Okay thanks but shouldn’t it be shiny if it’s copper this is like a dark brownsource ↗

PristinePea9377 · r/Plumbing · 1 upvotes

Nah it’s hard like construction adhesive!source ↗

miakpaeroe · r/Plumbing · 1 upvotes

Where this came up

People with this problem also raised